java - 开始另一个 Activity 时如何停止可运行对象？

我有一个Android应用程序，当值是“ 1”时会显示一个对话框，并反复显示该对话框，直到该值设置为“ 0”为止。 Runnable调用Handler会启动对话框，并且Runnable会延迟循环。

问题是，当我转到具有相同功能的其他活动并返回时，该对话框已经打开。这导致我的应用崩溃。我已经尝试使用removeMessage和removeCallback，但是仍然有问题。

Handler

Handler myHandler = new Handler()
{
    @Override
    public void handleMessage(Message msg)
    {
        /* Dialog */
        final AlertDialog.Builder AlertAlarm_Build;
        LayoutInflater inflater = (LayoutInflater) Settings_Activity.this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        AlertAlarm_Build = new AlertDialog.Builder(Settings_Activity.this);
        final View Disengaged_View;
        Disengaged_View = inflater.inflate(R.layout.disengage_dialog,null);
        final AlertDialog PasswordDialog = AlertAlarm_Build.create();
        PasswordDialog.show();

        final String[] given_password = new String[1];
        final boolean[] Password_Pass = {false};

        //respose
        final RequestQueue requestHander;
        requestHander = (RequestQueue) Volley.newRequestQueue(getApplicationContext());

...//Ask for password

        //New
        PasswordDialog.setOnDismissListener(new DialogInterface.OnDismissListener()
        {
            @Override
            public void onDismiss(DialogInterface dialogInterface)
            {
                recreate();
            }
        });

    }

};

Runnable

    //Runnable
final Runnable aMyRunnable = new Runnable()
{
    @Override
    public void run()
    {
        RequestQueue requestRun;
        requestRun = (RequestQueue) Volley.newRequestQueue(getApplicationContext());

        if(New_engaged[0].equals("1") && New_alarm[0].equals("1"))
        {
            set_engaged[0] = "1";
            myHandler.sendEmptyMessage(0);
        }
        else
        {
            requestRun.add(JOR_SystemCheck);
            myHandler.postDelayed(this,5000);

        }
    }
};

onStop

    protected void onStop() {
        super.onStop();
        myHandler.removeCallbacksAndMessages(aMyRunnable);
        myHandler.removeMessages(0);
    }

错误

/AndroidRuntime: FATAL EXCEPTION: main
              Process: com.example.djwiz.eclipse5, PID: 17705
              android.view.WindowManager$BadTokenException: Unable to add window -- token android.os.BinderProxy@f8866f3 is not valid; is your activity running?
                  at android.view.ViewRootImpl.setView(ViewRootImpl.java:765)
                  at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:356)
                  at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:92)
                  at android.app.Dialog.show(Dialog.java:330)
                  at com.example.djwiz.eclipse5.Settings_Activity$1.handleMessage(Settings_Activity.java:68)
                  at android.os.Handler.dispatchMessage(Handler.java:105)
                  at android.os.Looper.loop(Looper.java:164)
                  at android.app.ActivityThread.main(ActivityThread.java:6541)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)

最佳答案

基于removeCallbacksAndMessages的文档


  删除obj为令牌的回调和已发送消息的所有未决帖子。如果token为null，则将删除所有回调和消息


您的代码与任何令牌都不匹配：
myHandler.removeCallbacksAndMessages(aMyRunnable);

因此解决方案是使用：

myHandler.removeCallbacksAndMessages(null);