Android学习笔记(九)之Android 获取正在运行的Activity

首先是新建一个Android工程，然后修改【main.xml】文件如下：

添加一个ListView

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<ListView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:id="@+id/tasklist"
/>
</LinearLayout>

然后编辑【java代码】

package com.cayden.run;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import android.app.Activity;
import android.app.ActivityManager;
import android.app.ActivityManager.RunningTaskInfo;
import android.content.Context;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;

public class MyActivityRunDemo extends Activity {

private ListView tasklist=null;
private ListAdapter adapter=null;
private List<String> all=new ArrayList<String>();
private ActivityManager activityManager=null;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

tasklist=(ListView)this.findViewById(R.id.tasklist);

activityManager=(ActivityManager)super.getSystemService(Context.ACTIVITY_SERVICE);

listActivity();
}

public void listActivity(){
List<RunningTaskInfo> tasks=	activityManager.getRunningTasks(30);
Iterator<RunningTaskInfo> itInfo=tasks.iterator();
while(itInfo.hasNext()){
RunningTaskInfo info=itInfo.next();
all.add("【id="+info.id+"】,"+info.baseActivity.getClassName());

}
adapter=new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,this.all);

tasklist.setAdapter(adapter);
}
}

最后需要再配置所需要的权限【AndroidManifest.xml】

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.cayden.run"
android:versionCode="1"
android:versionName="1.0">
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name=".MyActivityRunDemo"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>

</application>
<uses-sdk android:minSdkVersion="8" />

<uses-permission android:name="android.permission.GET_TASKS"></uses-permission>
</manifest>

程序运行效果如图所示：



更多获取详见ActivityManager的API文档