//判斷應(yīng)用是否在前臺運行
public boolean isRunningForeground(Context context){
        String packageName=getPackageName(context);
        String topActivityClassName=getTopActivityName(context);
        System.out.println("packageName="+packageName+",topActivityClassName="+topActivityClassName);
        if (packageName!=null&&topActivityClassName!=null&&topActivityClassName.startsWith(packageName)) {
            System.out.println("應(yīng)用在前臺執(zhí)行");
            return true;
        } else {
            System.out.println("應(yīng)用在后臺執(zhí)行");
            return false;
        }
    }

// 判斷應(yīng)用是否在運行
public boolean isRun(Context context,String mPackageName){
        ActivityManager am = (ActivityManager)context.getSystemService(Context.ACTIVITY_SERVICE);
        List<RunningTaskInfo> list = am.getRunningTasks(100);
        boolean isAppRunning = false;
        //100表示取的最大的任務(wù)數(shù)，info.topActivity表示當(dāng)前正在運行的Activity，info.baseActivity表示系統(tǒng)后臺有此進程在運行
        for (RunningTaskInfo info : list) {
            if (info.topActivity.getPackageName().equals(mPackageName) || info.baseActivity.getPackageName().equals(mPackageName)) {
                isAppRunning = true;
                Log.i("ActivityService",info.topActivity.getPackageName() + " info.baseActivity.getPackageName()="+info.baseActivity.getPackageName());
                break;
            }
        }
        if(isAppRunning){
            Log.i("ActivityService", "該程序正在運行");
        }else{
            Log.i("ActivityService", "該程序沒有運行");
        }
        return isAppRunning;
}

//獲取棧頂ActivityName
public  String getTopActivityName(Context context){
        String topActivityClassName=null;
         ActivityManager activityManager =
        (ActivityManager)(context.getSystemService(android.content.Context.ACTIVITY_SERVICE )) ;
         List<runningtaskinfo> runningTaskInfos = activityManager.getRunningTasks(1) ;
         if(runningTaskInfos != null){
             ComponentName f=runningTaskInfos.get(0).topActivity;
             topActivityClassName=f.getClassName();
         }
         return topActivityClassName;
    }

    public String getPackageName(Context context){
         String packageName = context.getPackageName();  
         return packageName;
    }

/**
 * 用于管理Activity,獲取Activity
 * 在結(jié)束一個activity后應(yīng)該判斷當(dāng)前棧是否為空,為空則將本類引用置為null,以便于虛擬機回收內(nèi)存
 * 單例,調(diào)用 {@link #getActivityManager()} 獲取實例
 * 成員變量 {@link #mActivityStack} 應(yīng)該與系統(tǒng)的回退棧保持一致,所以在啟動activity的時候必須在其onCreate中
 * 將該activity加入棧頂,在activity結(jié)束時,必須在onDestroy中將該activity出棧
 */

public class ActivityManager {

    private static ReStack<Activity> mActivityStack;    //Activity棧
    private static ActivityManager mInstance;

    private ActivityManager() {
        mActivityStack = new ReStack<>();
    }

    /**
     * 獲取ActivityManager的單例.
     *
     * @return ActivityManager實例
     */
    public static ActivityManager getActivityManager() {
        if (mInstance == null) {
            mInstance = new ActivityManager();
        }
        return mInstance;
    }

    /**
     * 添加一個activity到棧頂.
     *
     * @param activity 添加的activity
     */
    public void pushActivity(Activity activity) {
        if (mActivityStack == null) {
            mActivityStack = new ReStack<>();
        }
        mActivityStack.push(activity);
    }

    /**
     * 獲取棧頂?shù)腁ctivity.
     *
     * @return 如果棧存在, 返回棧頂?shù)腶ctivity
     */
    public Activity peekActivity() {
        if (mActivityStack != null && !mActivityStack.isEmpty()) {
            return mActivityStack.peek();
        } else {
            return null;
        }
    }

    /**
     * 結(jié)束當(dāng)前的activity,在activity的onDestroy中調(diào)用.
     */
    public void popActivity() {
        if (mActivityStack != null && !mActivityStack.isEmpty()) {
            mActivityStack.pop();
        }
        //如果移除一個activity之后棧為空,將本類的引用取消,以便于讓虛擬機回收
        if (mActivityStack != null && mActivityStack.isEmpty()) {
            mInstance = null;
        }
    }

    /**
     * 結(jié)束最接近棧頂?shù)钠ヅ漕惷腶ctivity.
     * 遍歷到的不一定是被結(jié)束的,遍歷是從棧底開始查找,為了確定棧中有這個activity,并獲得一個引用
     * 刪除是從棧頂查找,結(jié)束查找到的第一個
     * 在activity外結(jié)束activity時調(diào)用
     *
     * @param klass 類名
     */
    public void popActivity(Class<? extends BaseActivity> klass) {
        for (Activity activity : mActivityStack) {
            if (activity != null && activity.getClass().equals(klass)) {
                activity.finish();
                break;              //只結(jié)束一個
            }
        }
    }

    //移除所有的Activity
    public void removeAll(){
        for (Activity activity : mActivityStack) {
            if (activity != null) {
                activity.finish();
                break;              
            }
        }
    }
}