Android – 第22页 – 蓝天白云

Android中用ListView实现表格部局

分类：Android 阅读 (2,985) No Responses »

8月 202012

* 本例使用ListView和自定义的行部局实现了一个最基本的表格部局
* 和一个可变长度的表格部局
* 并实现的简单的行组件的单击事件

XML文件1 activity_list_view_table.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent" >

 <ListView
 android:id="@+id/listView1"
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:layout_alignParentLeft="true"
 android:layout_alignParentTop="true" >

 </ListView>

</RelativeLayout>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent" >

<ListView

android:id="@+id/listView1"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_alignParentLeft="true"

android:layout_alignParentTop="true" >

</ListView>

</RelativeLayout>

XML文件2 listview_row_basic.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- 顶层使用RelativeLayout布局，用于自定义的listview的行 -->
<!-- layout_height用于设置行的高度，可以根据需要设置 -->
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="30dip" >

    <!-- 最左侧的TextView，宽度固定。layout_alignParentLeft和layout_alignParentTop用于对齐左上角 -->
    <!-- layout_margin用于和其他的组件隔开一定的距离 -->
    <!-- gravity属于用于设置内容的重心，此处为垂直居中，此外layout_height属于必须设置为match_parent即等于RelativeLayout的高度 -->
    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_margin="5dip"
        android:gravity="center_vertical"
        android:text="Small Text"
        android:textAppearance="?android:attr/textAppearanceSmall" />

    <!-- 最右侧的Button，设置layout_alignParentRight和layout_alignParentTop为true -->
    <Button
        android:id="@+id/button1"
        style="?android:attr/buttonStyleSmall"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:text="Delete" />

    <!-- 右数第二个Button，设置layout_toLeftOf为Button1 -->
    <Button
        android:id="@+id/button2"
        style="?android:attr/buttonStyleSmall"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_toLeftOf="@+id/button1"
        android:text="Edit" />

    <!-- 此TextView的内容比较长，layout_toLeftOf为@+id/button2， layout_toRightOf为@+id/textView1 -->
    <!-- 即占据了Button2和TextView1之间的全部空间 -->
    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_alignParentTop="true"
        android:layout_margin="5dip"
        android:layout_toLeftOf="@+id/button2"
        android:layout_toRightOf="@+id/textView1"
        android:gravity="center_vertical"
        android:text="Small Text"
        android:textAppearance="?android:attr/textAppearanceSmall" />

</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="match_parent"

android:layout_height="30dip" >

<TextView

android:id="@+id/textView1"

android:layout_width="wrap_content"

android:layout_height="match_parent"

android:layout_alignParentLeft="true"

android:layout_alignParentTop="true"

android:layout_margin="5dip"

android:gravity="center_vertical"

android:text="Small Text"

android:textAppearance="?android:attr/textAppearanceSmall" />

<Button

android:id="@+id/button1"

style="?android:attr/buttonStyleSmall"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentRight="true"

android:layout_alignParentTop="true"

android:text="Delete" />

<Button

android:id="@+id/button2"

style="?android:attr/buttonStyleSmall"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentTop="true"

android:layout_toLeftOf="@+id/button1"

android:text="Edit" />

<TextView

android:id="@+id/textView2"

android:layout_width="wrap_content"

android:layout_height="match_parent"

android:layout_alignParentTop="true"

android:layout_margin="5dip"

android:layout_toLeftOf="@+id/button2"

android:layout_toRightOf="@+id/textView1"

android:gravity="center_vertical"

android:text="Small Text"

android:textAppearance="?android:attr/textAppearanceSmall" />

</RelativeLayout>

XML文件3 listview_row.xml

<?xml version="1.0" encoding="utf-8"?>
<!-- 使用RelativeLayout做为顶层布局元素 -->
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <!-- 二级布局窗体加一个LinearLayout是为了使子LinearLayout能使用layout_weight来控制宽度 -->
    <LinearLayout
        android:id="@+id/linear_class_2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:gravity="fill_vertical" >

        <!-- 为了能控制第一个TextView的宽度所以把TextView嵌套到一个LinearLayout中，并设置其layout_weight为1  -->
        <!-- 此TextView显示的内容比较短，一般不会超出LinearLayout的长度 -->
        <!-- 设置gravity的值为center_vertical，意思为在本行垂直居中 -->
        <LinearLayout
            android:id="@+id/linearLayout1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:layout_weight="1" >
            <TextView
                android:id="@+id/textView1"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="Small Text"
                android:textAppearance="?android:attr/textAppearanceSmall" />
        </LinearLayout>

        <!-- 为了能控制第二个TextView的宽度所以把TextView嵌套到一个LinearLayout中，并设置其layout_weight为4  -->
        <!-- 此TextView显示的内容比较长，所在TextView2需要做一些其他的设置以使他不超出LinearLayout的长度 -->
        <LinearLayout
            android:id="@+id/linear_class_3_tv2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_vertical"
            android:layout_weight="4"
            android:clipChildren="false" >

            <TextView
                android:id="@+id/textView2"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:maxWidth="@dimen/padding_small"
                android:selectAllOnFocus="true"
                android:text="Small Text"
                android:textAppearance="?android:attr/textAppearanceSmall" />
        </LinearLayout>

        <!-- 两个Button为固定宽度，放在一个LinearLayout中，并设置LinearLayout的宽度为固定值90dip -->
        <LinearLayout
            android:layout_width="90dip"
            android:layout_height="wrap_content" >
            <Button
                android:id="@+id/button1"
                style="?android:attr/buttonStyleSmall"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:text="Edit" />
            <Button
                android:id="@+id/button2"
                style="?android:attr/buttonStyleSmall"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:text="Delete" />

        </LinearLayout>
    </LinearLayout>

</RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="match_parent"

android:layout_height="match_parent" >

<LinearLayout

android:id="@+id/linear_class_2"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentLeft="true"

android:layout_alignParentRight="true"

android:layout_alignParentTop="true"

android:gravity="fill_vertical" >

<LinearLayout

android:id="@+id/linearLayout1"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_gravity="center_vertical"

android:layout_weight="1" >

<TextView

android:id="@+id/textView1"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:text="Small Text"

android:textAppearance="?android:attr/textAppearanceSmall" />

</LinearLayout>

<LinearLayout

android:id="@+id/linear_class_3_tv2"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_gravity="center_vertical"

android:layout_weight="4"

android:clipChildren="false" >

<TextView

android:id="@+id/textView2"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:maxWidth="@dimen/padding_small"

android:selectAllOnFocus="true"

android:text="Small Text"

android:textAppearance="?android:attr/textAppearanceSmall" />

</LinearLayout>

<LinearLayout

android:layout_width="90dip"

android:layout_height="wrap_content" >

<Button

android:id="@+id/button1"

style="?android:attr/buttonStyleSmall"

android:layout_width="wrap_content"

android:layout_height="match_parent"

android:text="Edit" />

<Button

android:id="@+id/button2"

style="?android:attr/buttonStyleSmall"

android:layout_width="wrap_content"

android:layout_height="match_parent"

android:text="Delete" />

</LinearLayout>

</RelativeLayout>

JAVA代码文件 ListViewTableActivity.java

/*******************************************************************************
 * 本例使用ListView和自定义的行部局实现了一个最基本的表格部局
 * 和一个可变长度的表格部局
 * 并实现的简单的行组件的单击事件
 *
 * 作者：http://svn1.bcoder.com
 *
 *******************************************************************************/
package com.bcoder.listviewtable;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.text.TextUtils.TruncateAt;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.TextView;

public class ListViewTableActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_list_view_table);

        ArrayList&lt;HashMap&lt;String, String&gt;&gt; dItems = new ArrayList&lt;HashMap&lt;String, String&gt;&gt;();

        HashMap&lt;String, String&gt; mItem1 = new HashMap&lt;String, String&gt;();
        mItem1.put("Name", "张三");
        mItem1.put("URL", "http://svn1.bcoder.com");
        dItems.add(mItem1);

        HashMap&lt;String, String&gt; mItem2 = new HashMap&lt;String, String&gt;();
        mItem2.put("Name", "李四");
        mItem2.put("URL", "http://svn1.bcoder.com/?page_id=111");
        dItems.add(mItem2);

        HashMap&lt;String, String&gt; mItem3 = new HashMap&lt;String, String&gt;();
        mItem3.put("Name", "李四");
        mItem3.put("URL", "http://svn1.bcoder.com/?page_id=111");
        dItems.add(mItem3);

        HashMap&lt;String, String&gt; mItem4 = new HashMap&lt;String, String&gt;();
        mItem4.put("Name", "李四");
        mItem4.put("URL", "http://svn1.bcoder.com/?page_id=111");
        dItems.add(mItem4);

        HashMap&lt;String, String&gt; mItem5 = new HashMap&lt;String, String&gt;();
        mItem5.put("Name", "李四");
        mItem5.put("URL", "http://svn1.bcoder.com/?page_id=111");
        dItems.add(mItem5);

        HashMap&lt;String, String&gt; mItem6 = new HashMap&lt;String, String&gt;();
        mItem6.put("Name", "李四");
        mItem6.put("URL", "http://svn1.bcoder.com/?page_id=111");
        dItems.add(mItem6);

        HashMap&lt;String, String&gt; mItem7 = new HashMap&lt;String, String&gt;();
        mItem7.put("Name", "李四");
        mItem7.put("URL", "http://svn1.bcoder.com/?page_id=111");
        dItems.add(mItem7);

        HashMap&lt;String, String&gt; mItem8 = new HashMap&lt;String, String&gt;();
        mItem8.put("Name", "李四");
        mItem8.put("URL", "http://svn1.bcoder.com/?page_id=111");
        dItems.add(mItem8);

        HashMap&lt;String, String&gt; mItem9 = new HashMap&lt;String, String&gt;();
        mItem9.put("Name", "李四");
        mItem9.put("URL", "http://svn1.bcoder.com/?page_id=111");
        dItems.add(mItem9);

        HashMap&lt;String, String&gt; mItem10 = new HashMap&lt;String, String&gt;();
        mItem10.put("Name", "李四");
        mItem10.put("URL", "http://svn1.bcoder.com/?page_id=111");
        dItems.add(mItem10);

        //下面两行用于切换使用listview_row_basic或者listview_row的行部局
        MyAdapter adapter = new MyAdapter(this, dItems, R.layout.listview_row,
        //MyAdapter adapter = new MyAdapter(this, dItems, R.layout.listview_row_basic,
        		new String[] {"Name", "URL"},
        		new int[] {R.id.textView1, R.id.textView2});

        ListView lv = (ListView)findViewById(R.id.listView1);
        lv.setAdapter(adapter);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_list_view_table, menu);
        return true;
    }

    public class MyAdapter extends SimpleAdapter{

		public MyAdapter(Context context, List&lt;? extends Map&lt;String, ?&gt;&gt; data,
				int resource, String[] from, int[] to) {
			super(context, data, resource, from, to);
		}

		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			View curRowView = super.getView(position, convertView, parent);
			final TextView tv = (TextView)curRowView.findViewById(R.id.textView2);
			//用于设置当字符长度超出TextView的宽度时，在末尾显示为"..."
			//此属于也可以在activity设计界面中设置，还可以为其他值，如：START, MIDDLE 或者 MARQUEE
			tv.setEllipsize(TruncateAt.END);
			//设置此属于上面的属性才会生效
			tv.setSingleLine(true);
			//设置最大行数为1，则最多只显示一行，此属性可以在activity设计界面中设置
			tv.setMaxLines(1);

			OnClickListener onUrlTxtClick = new OnClickListener() {

				public void onClick(View v) {
		    		Uri uri = Uri.parse(tv.getText().toString());
		    		Intent logintent = new Intent(Intent.ACTION_VIEW, uri);
		    		startActivity(logintent);
				}

			};

			//实现TextView的点击效果
			tv.setOnClickListener(onUrlTxtClick);

			return curRowView;
		}
    }

}

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

/*******************************************************************************

* 本例使用ListView和自定义的行部局实现了一个最基本的表格部局

* 和一个可变长度的表格部局

* 并实现的简单的行组件的单击事件

* 作者：http://svn1.bcoder.com

*******************************************************************************/

package com.bcoder.listviewtable;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

import android.app.Activity;

import android.content.Context;

import android.content.Intent;

import android.net.Uri;

import android.os.Bundle;

import android.text.TextUtils.TruncateAt;

import android.view.Menu;

import android.view.View;

import android.view.View.OnClickListener;

import android.view.ViewGroup;

import android.widget.LinearLayout;

import android.widget.ListView;

import android.widget.SimpleAdapter;

import android.widget.TextView;

public class ListViewTableActivity extends Activity {

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_list_view_table);

ArrayList<HashMap<String, String>> dItems = new ArrayList<HashMap<String, String>>();

HashMap<String, String> mItem1 = new HashMap<String, String>();

mItem1.put("Name", "张三");

mItem1.put("URL", "http://svn1.bcoder.com");

dItems.add(mItem1);

HashMap<String, String> mItem2 = new HashMap<String, String>();

mItem2.put("Name", "李四");

mItem2.put("URL", "http://svn1.bcoder.com/?page_id=111");

dItems.add(mItem2);

HashMap<String, String> mItem3 = new HashMap<String, String>();

mItem3.put("Name", "李四");

mItem3.put("URL", "http://svn1.bcoder.com/?page_id=111");

dItems.add(mItem3);

HashMap<String, String> mItem4 = new HashMap<String, String>();

mItem4.put("Name", "李四");

mItem4.put("URL", "http://svn1.bcoder.com/?page_id=111");

dItems.add(mItem4);

HashMap<String, String> mItem5 = new HashMap<String, String>();

mItem5.put("Name", "李四");

mItem5.put("URL", "http://svn1.bcoder.com/?page_id=111");

dItems.add(mItem5);

HashMap<String, String> mItem6 = new HashMap<String, String>();

mItem6.put("Name", "李四");

mItem6.put("URL", "http://svn1.bcoder.com/?page_id=111");

dItems.add(mItem6);

HashMap<String, String> mItem7 = new HashMap<String, String>();

mItem7.put("Name", "李四");

mItem7.put("URL", "http://svn1.bcoder.com/?page_id=111");

dItems.add(mItem7);

HashMap<String, String> mItem8 = new HashMap<String, String>();

mItem8.put("Name", "李四");

mItem8.put("URL", "http://svn1.bcoder.com/?page_id=111");

dItems.add(mItem8);

HashMap<String, String> mItem9 = new HashMap<String, String>();

mItem9.put("Name", "李四");

mItem9.put("URL", "http://svn1.bcoder.com/?page_id=111");

dItems.add(mItem9);

HashMap<String, String> mItem10 = new HashMap<String, String>();

mItem10.put("Name", "李四");

mItem10.put("URL", "http://svn1.bcoder.com/?page_id=111");

dItems.add(mItem10);

//下面两行用于切换使用listview_row_basic或者listview_row的行部局

MyAdapter adapter = new MyAdapter(this, dItems, R.layout.listview_row,

//MyAdapter adapter = new MyAdapter(this, dItems, R.layout.listview_row_basic,

new String[] {"Name", "URL"},

new int[] {R.id.textView1, R.id.textView2});

ListView lv = (ListView)findViewById(R.id.listView1);

lv.setAdapter(adapter);

}

@Override

public boolean onCreateOptionsMenu(Menu menu) {

getMenuInflater().inflate(R.menu.activity_list_view_table, menu);

return true;

}

public class MyAdapter extends SimpleAdapter{

public MyAdapter(Context context, List<? extends Map<String, ?>> data,

int resource, String[] from, int[] to) {

super(context, data, resource, from, to);

}

@Override

public View getView(int position, View convertView, ViewGroup parent) {

View curRowView = super.getView(position, convertView, parent);

final TextView tv = (TextView)curRowView.findViewById(R.id.textView2);

//用于设置当字符长度超出TextView的宽度时，在末尾显示为"..."

//此属于也可以在activity设计界面中设置，还可以为其他值，如：START, MIDDLE 或者 MARQUEE

tv.setEllipsize(TruncateAt.END);

//设置此属于上面的属性才会生效

tv.setSingleLine(true);

//设置最大行数为1，则最多只显示一行，此属性可以在activity设计界面中设置

tv.setMaxLines(1);

OnClickListener onUrlTxtClick = new OnClickListener() {

public void onClick(View v) {

Uri uri = Uri.parse(tv.getText().toString());

Intent logintent = new Intent(Intent.ACTION_VIEW, uri);

startActivity(logintent);

}

};

//实现TextView的点击效果

tv.setOnClickListener(onUrlTxtClick);

return curRowView;

}

———————————

点击此下下载源代码

———————————

Android中调用邮件发送程序

分类：Android 阅读 (2,132) No Responses »

8月 092012

本例主要是使用了Intent对象的隐式调用方式，设置intent的Action, Data和Extra来传递的相关的信息

activity布局代码如下：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <EditText
        android:id="@+id/txtReceiver"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_alignParentTop="true"
        android:layout_toRightOf="@+id/textView1"
        android:ems="10"
        android:inputType="textEmailAddress"
        android:text="yourmail@svn1.bcoder.com" />

    <EditText
        android:id="@+id/txtEmailContent"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentRight="true"
        android:layout_below="@+id/txtReceiver"
        android:ems="10"
        android:gravity="top"
        android:inputType="textMultiLine"
        android:lines="10"
        android:text="Here is the bodytext!" />

    <Button
        android:id="@+id/button1"
        style="?android:attr/buttonStyleSmall"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_below="@+id/txtEmailContent"
        android:layout_marginRight="31dp"
        android:layout_marginTop="16dp"
        android:onClick="callEmailApp"
        android:text="Call" />

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/txtReceiver"
        android:layout_alignBottom="@+id/txtReceiver"
        android:layout_alignParentLeft="true"
        android:text="Receiver:"
        android:textAppearance="?android:attr/textAppearanceMedium" />

</RelativeLayout>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent" >

<EditText

android:id="@+id/txtReceiver"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentRight="true"

android:layout_alignParentTop="true"

android:layout_toRightOf="@+id/textView1"

android:ems="10"

android:inputType="textEmailAddress"

android:text="yourmail@svn1.bcoder.com" />

<EditText

android:id="@+id/txtEmailContent"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentLeft="true"

android:layout_alignParentRight="true"

android:layout_below="@+id/txtReceiver"

android:ems="10"

android:gravity="top"

android:inputType="textMultiLine"

android:lines="10"

android:text="Here is the bodytext!" />

<Button

android:id="@+id/button1"

style="?android:attr/buttonStyleSmall"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentRight="true"

android:layout_below="@+id/txtEmailContent"

android:layout_marginRight="31dp"

android:layout_marginTop="16dp"

android:onClick="callEmailApp"

android:text="Call" />

<TextView

android:id="@+id/textView1"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignBaseline="@+id/txtReceiver"

android:layout_alignBottom="@+id/txtReceiver"

android:layout_alignParentLeft="true"

android:text="Receiver:"

android:textAppearance="?android:attr/textAppearanceMedium" />

</RelativeLayout>

类代码如下：

package com.bcoder.callmailapp;

import android.net.Uri;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;
import android.support.v4.app.NavUtils;

public class MainActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

    public void callEmailApp(View view){
    	EditText txtReceiver = (EditText)findViewById(R.id.txtReceiver);
    	EditText txtContent = (EditText)findViewById(R.id.txtEmailContent);
    	Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("mailto:" + txtReceiver.getText().toString()));
    	intent.putExtra(Intent.EXTRA_SUBJECT, "Welcome to bcoder.com");
    	intent.putExtra(Intent.EXTRA_BCC, "bcc@svn1.bcoder.com");
    	intent.putExtra(Intent.EXTRA_CC, "cc@svn1.bcoder.com");
    	intent.putExtra(Intent.EXTRA_TEXT, txtContent.getText().toString());
    	intent.putExtra(Intent.EXTRA_EMAIL, new String[]{"coder1@svn1.bcoder.com", "coder2@svn1.bcoder.com"});
    	startActivity(intent);
    }

}

package com.bcoder.callmailapp;

import android.net.Uri;

import android.os.Bundle;

import android.app.Activity;

import android.content.Intent;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.widget.EditText;

import android.support.v4.app.NavUtils;

public class MainActivity extends Activity {

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

}

@Override

public boolean onCreateOptionsMenu(Menu menu) {

getMenuInflater().inflate(R.menu.activity_main, menu);

return true;

}

public void callEmailApp(View view){

EditText txtReceiver = (EditText)findViewById(R.id.txtReceiver);

EditText txtContent = (EditText)findViewById(R.id.txtEmailContent);

Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse("mailto:" + txtReceiver.getText().toString()));

intent.putExtra(Intent.EXTRA_SUBJECT, "Welcome to bcoder.com");

intent.putExtra(Intent.EXTRA_BCC, "bcc@svn1.bcoder.com");

intent.putExtra(Intent.EXTRA_CC, "cc@svn1.bcoder.com");

intent.putExtra(Intent.EXTRA_TEXT, txtContent.getText().toString());

intent.putExtra(Intent.EXTRA_EMAIL, new String[]{"coder1@svn1.bcoder.com", "coder2@svn1.bcoder.com"});

startActivity(intent);

}

本代码调试环境：

* Eclipse: Indigo Service Release 2
* Android SDK: 4.0(API LEVEL 14)

点击这里下载CallMailApp

注意：

1. 如果你还没有在你的手机或者AVD上创建相关的email帐户，运行此程序时会提示Unsupported action(不支持的Action)!

Android中service开发总结

分类：Android 阅读 (2,517) No Responses »

8月 082012

1、为什么要使用service?

在我们开发的应用中，有的时候需要做一些长期运行的任务，比如下载文件、音乐播放器、闹钟或者邮件程序等。由于Android系统会根据系统资源使用情况自动清理闲置的后台程序，所以普通的Activity程序在运行一段时间后就有可能被系统清理掉，不能达到长期运行的效果。而包含service的进程属于优先权比较高的（关于进程的生命周期相关知识请点击这里查看）不容易被系统清理掉，所以对那些应用来说，选择service是必要的。

2、创建一个Service

在工程节点或者包节点上右键，选择”New->Class”，输入包名，类名称，SuperClass输入或者选择android.app.Service，点击ok，创建一个服务类成功，创建完成后初始化代码如下：

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;


public class TestService extends Service {

	@Override
	public IBinder onBind(Intent intent) {
		// TODO Auto-generated method stub
		return null;
	}

}

import android.app.Service;

import android.content.Intent;

import android.os.IBinder;

public class TestService extends Service {

@Override

public IBinder onBind(Intent intent) {

// TODO Auto-generated method stub

return null;

}

创建完成后还无法使用此服务，需要在AndroidManifestXml中声明该服务类，示例如下：

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <service android:name="TestService" android:label="@string/app_name" android:icon="@drawable/ic_launcher"></service>
    </application>

<application

android:allowBackup="true"

android:icon="@drawable/ic_launcher"

android:label="@string/app_name"

android:theme="@style/AppTheme" >

<activity

android:name=".MainActivity"

android:label="@string/app_name" >

<intent-filter>

</intent-filter>

</activity>

</application>

3、服务类的一些重要方法

getApplication()

Return the application that owns this service.

onBind(Intent intent)

Return the communication channel to the service.

onConfigurationChanged(Configuration newConfig)

Called by the system when the device configuration changes while your component is running.

onCreate()

Called by the system when the service is first created.

onDestroy()

Called by the system to notify a Service that it is no longer used and is being removed.

onLowMemory()

This is called when the overall system is running low on memory, and actively running processes should trim their memory usage.

onRebind(Intent intent)

Called when new clients have connected to the service, after it had previously been notified that all had disconnected in itsonUnbind(Intent).

onStart(Intent intent, int startId)

This method was deprecated in API level 5. Implement onStartCommand(Intent, int, int) instead.

onStartCommand(Intent intent, int flags, int startId)

Called by the system every time a client explicitly starts the service by calling startService(Intent), providing the arguments it supplied and a unique integer token representing the start request.

onTaskRemoved(Intent rootIntent)

This is called if the service is currently running and the user has removed a task that comes from the service’s application.

onTrimMemory(int level)

Called when the operating system has determined that it is a good time for a process to trim unneeded memory from its process.

onUnbind(Intent intent)

Called when all clients have disconnected from a particular interface published by the service.

startForeground(int id, Notification notification)

Make this service run in the foreground, supplying the ongoing notification to be shown to the user while in this state.

stopForeground(boolean removeNotification)

Remove this service from foreground state, allowing it to be killed if more memory is needed.

stopSelf()

Stop the service, if it was previously started.

stopSelf(int startId)

Old version of stopSelfResult(int) that doesn’t return a result.

stopSelfResult(int startId)

Stop the service if the most recent time it was started was startId.

4、Service的调用方法

Service可能通过两种方法启动，一种是通过startService另外一种是通过bindService

1) startServie的声明如下：public abstract ComponentName startService (Intent service)

参数说明：service是你要启动的服务对象，通过Intent构造，你可以在Intent对象中加入其他需要的参数，以在服务中使用。执行此函数后，如果服务未启动则系统会创建此服务并执行，如果执行此函数时服务已经在运行，则服务会继续执行。

	Intent servicentent = new Intent(this, CloudNoteService.class);
	//servicentent.putExtra("MusicFile", "")
	this.startService(servicentent);

Intent servicentent = new Intent(this, CloudNoteService.class);

//servicentent.putExtra("MusicFile", "")

this.startService(servicentent);

每次调用startService时都会触发服务内的android.app.Service.onStartCommand方法，此机制提供一个方便的方法通过Intent参数传入一些需要的参数，以避免必须再使用BindService才能实现的功能。

终止由startService启动的服务方法：一种是可以在服务内部调用stopSelf()来停止服务，另一种是在调用startService的context中通过调用stopService来终止

2) bindService声明如下：public abstract boolean bindService (Intent service, ServiceConnection conn, int flags)

参数说明：
service: 是要绑定的服务的实例标识，
conn: 用于接收成功绑定或者结束绑定时的通知，在连接时可以接收service返回的对象，
flags: 为绑定选项，可能为0, BIND_AUTO_CREATE, BIND_DEBUG_UNBIND, BIND_NOT_FOREGROUND, BIND_ABOVE_CLIENT, BIND_ALLOW_OOM_MANAGEMENT, BIND_WAIVE_PRIORITY.

对于由startService启动的服务，也可以使用此函数进行绑定。如果服务没有启动，可以设置flags为BIND_AUTO_CREATE，这样执行此函数时服务会被自动创建。

只有当调用该服务存在的时候系统才认为该服务有必须继续执行代码，比如当调用该服务的Activity停止或者销毁后它绑定的服务也会停止工作。所以在执行长期操作的时候不要在bindService中执行，即不要在Service的onbind函数中启动相应的定时器，否则当activity结束后，该定时器也会不再执行工作，而应该先用startService启动服务，并在服务的onStartCommand中执行定时器操作。

注意：

1、在使用一个service前必须在AndroidManifest.xml中定义该服务类名称，如：<service android:name=”Em8CheckerService”></service>

Different sytles to show data in listview

分类：Android 阅读 (2,533) No Responses »

7月 232012

Bellow is several different styles to show data in listview, you can use it to select your desired style.

Just show it very simply, if you have suggestions, please contact us.

Soure code file have been attached.

Download Source Code of the article listviewTest

This gallery contains 0 photos

Errors made by myself when develop android app

分类：Android 阅读 (1,934) No Responses »

7月 162012

1. App crashes when it starts, because I make a error to set TextView.textcolor to a String resource Value, it should be a drawable resource value

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <string name="mainbtnlogin">Login</string>
    <drawable name="general_back_color">#FFFFFF</drawable> //this is right to assign to a color type variable
    <string name="general_text_color">#000000</string> //this is wrong to assign to a color type variable
    <drawable name="general_linkable_color">#0000FF</drawable>
    <string name="value_zero">0</string>
</resources>

<?xml version="1.0" encoding="utf-8"?>

<string name="mainbtnlogin">Login</string>

<drawable name="general_back_color">#FFFFFF</drawable> //this is right to assign to a color type variable

<string name="general_text_color">#000000</string> //this is wrong to assign to a color type variable

</resources>

2. I wrote a function which used Context of the activity. But when I finished coding, eclipse gave an error message. After a about 1 hour research, I finally found I wrote the function in the subclass of the activity. After moving the function to the main class, it works.

package em8.admin;

//import a lot of packages

public class Em8MainActivity extends Activity {
	/** Called when the activity is first created. */
    @SuppressLint({ "ParserError", "NewApi" })
	@Override
    public void onCreate(Bundle savedInstanceState) {
        setContentView(R.layout.main);
        ...
    }

    public class ShowStatisticsTask extends AsyncTask&lt;String, integer, Long&gt;{
    	LogResItem lrItem = null;
    	SharedPreferences prefs = getSharedPreferences(ConstData.Settings_file_name, MODE_PRIVATE);
	    @Override
	    protected Long doInBackground(String... params) {
	    }

	    protected void onPostExecute(Long result) {
	    }

            //It is difficult to find, right?
	    public void showNotification(int icon,String tickertext,String title,String content){
	    	Notification notification=new Notification(icon,tickertext,System.currentTimeMillis());
	    	notification.defaults=Notification.DEFAULT_ALL;

	    	PendingIntent pt=PendingIntent.getActivity(this, 0, getIntent(), 0);
	    	notification.setLatestEventInfo(this,title,content,pt);
	    	notifyMgr.notify(notification_id, notification);
	    }

    }
}

package em8.admin;

//import a lot of packages

public class Em8MainActivity extends Activity {

/** Called when the activity is first created. */

@SuppressLint({ "ParserError", "NewApi" })

@Override

public void onCreate(Bundle savedInstanceState) {

setContentView(R.layout.main);

...

}

public class ShowStatisticsTask extends AsyncTask<String, integer, Long>{

LogResItem lrItem = null;

SharedPreferences prefs = getSharedPreferences(ConstData.Settings_file_name, MODE_PRIVATE);

@Override

protected Long doInBackground(String... params) {

}

protected void onPostExecute(Long result) {

}

//It is difficult to find, right?

public void showNotification(int icon,String tickertext,String title,String content){

Notification notification=new Notification(icon,tickertext,System.currentTimeMillis());

notification.defaults=Notification.DEFAULT_ALL;

PendingIntent pt=PendingIntent.getActivity(this, 0, getIntent(), 0);

notification.setLatestEventInfo(this,title,content,pt);

notifyMgr.notify(notification_id, notification);

}

3. (be continued…)

"Integer types not allowed" error

分类：Android 阅读 (2,151) No Responses »

7月 162012

When I gave a margin value 10 to TextView, the eclipse give a below error message.

error: Error: Integer types not allowed (at ‘layout_margin’ with value ’10’).

I searched on internet, and found can’t give a integer value to it, should use 10dip.

StrictMode of android

分类：Android 阅读 (2,308) No Responses »

7月 122012

StrictMode is a developer tool which used to detect accident in program. For example, if you do internet access or local file operation in the UI directly, the strictmode mechanism will throw an error to the application.

StrictMode is used default since Android 3.0(HoneyComb).

example of a wrong case

	public void downloadHtml(View view) throws IOException{
    	String response = &quot;&quot;;
    	DefaultHttpClient client = new DefaultHttpClient();
    	HttpGet httpGet = new HttpGet(&quot;http://svn1.bcoder.com&quot;);
		HttpResponse execute = client.execute(httpGet);
		InputStream content = execute.getEntity().getContent();

		BufferedReader buffer = new BufferedReader(new InputStreamReader(content));
		String s = &quot;&quot;;
		while ((s = buffer.readLine()) != null) {
			response += s;
		}
		TextView tv = (TextView)findViewById(R.id.textView1);
    	tv.setText(response);
    }

public void downloadHtml(View view) throws IOException{

String response = "";

DefaultHttpClient client = new DefaultHttpClient();

HttpGet httpGet = new HttpGet("http://svn1.bcoder.com");

HttpResponse execute = client.execute(httpGet);

InputStream content = execute.getEntity().getContent();

BufferedReader buffer = new BufferedReader(new InputStreamReader(content));

String s = "";

while ((s = buffer.readLine()) != null) {

response += s;

}

TextView tv = (TextView)findViewById(R.id.textView1);

tv.setText(response);

}

If you request an url like above, your app will crashes.

So the right thing we do this is we can run the internet request in thread(Threads, AsyncTask, Handler), I give a simple by AsyncTask.

	public void downloadHtml(View view) throws IOException{
	DownloadHtmlTask task = new DownloadHtmlTask();
	task.execute(new String[] { &quot;http://svn1.bcoder.com&quot; });
    }

	private class DownloadHtmlTask extends AsyncTask&lt;String, Void, String&gt; {
		@Override
		protected String doInBackground(String... urls) {
			String response = &quot;&quot;;
			InputStream in = null;
			for (String url : urls) {
				DefaultHttpClient client = new DefaultHttpClient();
				HttpGet httpGet = new HttpGet(url);
				try {
			    	URL urlget = new URL(url);
			    	HttpURLConnection conn = (HttpURLConnection)urlget.openConnection();

			    	conn.connect();

			    	in = (conn.getInputStream());
					BufferedReader buffer = new BufferedReader(new InputStreamReader(in));
					String s = &quot;&quot;;
					while ((s = buffer.readLine()) != null) {
						response += s;
					}

				} catch (Exception e) {
					e.printStackTrace();
				}
			}
			return response;
		}

		@Override
		protected void onPostExecute(String result) {
			TextView textView =  (TextView)findViewById(R.id.textView1);;
			textView.setText(result);
		}
	}

public void downloadHtml(View view) throws IOException{

DownloadHtmlTask task = new DownloadHtmlTask();

task.execute(new String[] { "http://svn1.bcoder.com" });

}

private class DownloadHtmlTask extends AsyncTask<String, Void, String> {

@Override

protected String doInBackground(String... urls) {

String response = "";

InputStream in = null;

for (String url : urls) {

DefaultHttpClient client = new DefaultHttpClient();

HttpGet httpGet = new HttpGet(url);

try {

URL urlget = new URL(url);

HttpURLConnection conn = (HttpURLConnection)urlget.openConnection();

conn.connect();

in = (conn.getInputStream());

BufferedReader buffer = new BufferedReader(new InputStreamReader(in));

String s = "";

while ((s = buffer.readLine()) != null) {

response += s;

}

} catch (Exception e) {

e.printStackTrace();

}

return response;

}

@Override

protected void onPostExecute(String result) {

TextView textView = (TextView)findViewById(R.id.textView1);;

textView.setText(result);

}

It looks very troublesome when we just debug the program, so we can also use a simple code to disable ThreadPolicy to avoid errors.

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();
        StrictMode.setThreadPolicy(policy);
    }

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder().permitAll().build();

StrictMode.setThreadPolicy(policy);

}

…

Page 22 of 22 Newer Entries 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22