android 判断当前应用的是否为前台task 判断当前的activity是否为top activity 判断当前应用的是否为后台task

import java.util.List;

import android.app.Activity;

import android.app.ActivityManager;

import android.app.ActivityManager.RunningTaskInfo;

import android.content.Context;

import android.util.Log;

public class SystemUtils {

public static final int DEFAULT_TASK_NUM = 100;

public static List<RunningTaskInfo> getRunningTask(Context context) {

return getRunningTask(context, DEFAULT_TASK_NUM);

}

public static List<RunningTaskInfo> getRunningTask(Context context, int num) {

if (context != null) {

ActivityManager am = (ActivityManager) context

.getSystemService(Context.ACTIVITY_SERVICE);

List<RunningTaskInfo> rTasks = am.getRunningTasks(1);

return rTasks;

}

return null;

}

public static boolean isTopActivity(Activity activity) {

return isTopActivity(activity, activity.getClass());

}

public static boolean isTopActivity(Context context,

Class<? extends Activity> activity) {

return isTopActivity(context, activity.getName());

}

/**

* 判断当前的activity是否为top activity

* @param context

* @param className

* @return

*/

public static boolean isTopActivity(Context context, String className) {

List<RunningTaskInfo> rTasks = getRunningTask(context, 1);

for (RunningTaskInfo task : rTasks) {

Log.d("SystemUtils", "isTopActivity:" + task.topActivity.getClassName()

+ "|" + className);

if (task.topActivity.getClassName().equals(className)) {

return true;

}

}

return false;

}

/**

* 判断当前应用的是否为前台task

*

* @param context

* @return

*/

public static boolean isAppForgroud(Context context) {

if (context != null) {

String packName = context.getPackageName();

List<RunningTaskInfo> rTasks = getRunningTask(context, 1);

RunningTaskInfo task = rTasks.get(0);

return packName.equalsIgnoreCase(task.topActivity.getPackageName());

}

return false;

}

/**

* 判断当前应用的是否为后台task

*

* @param context

* @param packName

* @return

*/

public static boolean isAppBackgroud(Context context) {

if (context != null) {

String packName = context.getPackageName();

List<RunningTaskInfo> rTasks = getRunningTask(context, 1);

RunningTaskInfo task = rTasks.get(0);

return !packName

.equalsIgnoreCase(task.topActivity.getPackageName());

}

return false;

}

}