Android ActivityManager使用案例详解

//判断应用是否在前台运行
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("应用在前台执行");
            return true;
        } else {
            System.out.println("应用在后台执行");
            return false;
        }
    }

// 判断应用是否在运行
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表示取的最大的任务数，info.topActivity表示当前正在运行的Activity，info.baseActivity表示系统后台有此进程在运行
        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", "该程序正在运行");
        }else{
            Log.i("ActivityService", "该程序没有运行");
        }
        return isAppRunning;
}

//获取栈顶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;
    }

public class ActivityManager {

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

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

    
    public static ActivityManager getActivityManager() {
        if (mInstance == null) {
            mInstance = new ActivityManager();
        }
        return mInstance;
    }

    
    public void pushActivity(Activity activity) {
        if (mActivityStack == null) {
            mActivityStack = new ReStack<>();
        }
        mActivityStack.push(activity);
    }

    
    public Activity peekActivity() {
        if (mActivityStack != null && !mActivityStack.isEmpty()) {
            return mActivityStack.peek();
        } else {
            return null;
        }
    }

    
    public void popActivity() {
        if (mActivityStack != null && !mActivityStack.isEmpty()) {
            mActivityStack.pop();
        }
        //如果移除一个activity之后栈为空,将本类的引用取消,以便于让虚拟机回收
        if (mActivityStack != null && mActivityStack.isEmpty()) {
            mInstance = null;
        }
    }

    
    public void popActivity(Class<? extends BaseActivity> klass) {
        for (Activity activity : mActivityStack) {
            if (activity != null && activity.getClass().equals(klass)) {
                activity.finish();
                break;              //只结束一个
            }
        }
    }

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