Question

在我的应用程序中，FirstActivity Asynctask在asyntask结束时调用secondactivity将被打开

当asyntask正在运行时app处于后台完成异步任务后应用程序自动进入前台而无需任何用户交互

如何避免它？

Answer 1

在android中，我们可以发现应用程序在前台或后台是这样的：

ActivityManager activityManager = (ActivityManager) getApplicationContext()
.getSystemService(Activity.ACTIVITY_SERVICE);
String className = activityManager.getRunningTasks(1).get(0).topActivity
.getClassName();

if (className.equals("your activity class name with package")) {
//ToDO
}

Answer 2

在使用如下方法开始第二个活动之前，检查您的应用程序是否在前台：

public static boolean isApplicationSentToBackground(final Context context) {
    ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
    List<RunningTaskInfo> tasks = am.getRunningTasks(1);
    if (!tasks.isEmpty()) {
        ComponentName topActivity = tasks.get(0).topActivity;
        if (!topActivity.getPackageName().equals(context.getPackageName())) {
            return true;
        }
    }
    return false;
}

Answer 3

检查是否打开了任何活动。

    /***
     * Checking Whether any Activity of Application is running or not
     * @param context
     * @return
     */
    public boolean isForeground(Context context) {

        // Get the Activity Manager
        ActivityManager manager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);

        // Get a list of running tasks, we are only interested in the last one, 
        // the top most so we give a 1 as parameter so we only get the topmost.
        List< ActivityManager.RunningTaskInfo > task = manager.getRunningTasks(1); 

        // Get the info we need for comparison.
        ComponentName componentInfo = task.get(0).topActivity;

        // Check if it matches our package name.
        if(componentInfo.getPackageName().equals(context.getPackageName())) 
            return true;

        // If not then our app is not on the foreground.
        return false;
    }

使用它：

if(isForeground(context)) {
    //Nothing to do
} else {

    /**
          You can do here what you want to do
      **/

}

Android应用自动进入前台

3 个答案: