Question

我想在用户按下手机时显示警告框。所以我只使用::

public boolean onKeyDown(int keyCode, KeyEvent event) {
        if ((keyCode == KeyEvent.KEYCODE_BACK)) {
            try {
                  AlertDialog.Builder alertbox = new AlertDialog.Builder(this);
                    alertbox.setMessage("This is the alertbox!");
                    alertbox.setPositiveButton("Yes", new DialogInterface.OnClickListener() {


                        public void onClick(DialogInterface arg0, int arg1) {
                            Toast.makeText(getApplicationContext(), "'Yes' button clicked", Toast.LENGTH_SHORT).show();
                        }
                    });

                    // set a negative/no button and create a listener
                    alertbox.setNegativeButton("No", new DialogInterface.OnClickListener() {


                        public void onClick(DialogInterface arg0, int arg1) {
                            Toast.makeText(getApplicationContext(), "'No' button clicked", Toast.LENGTH_SHORT).show();
                        }
                    });

                    alertbox.show();
          stopService(new Intent(this, BackServices.class));
                finish();
            } catch (Exception e) {
                // TODO: handle exception
            }
        }
        return super.onKeyDown(keyCode, event);
    }

but problem is ：当我按下alertbox show但它退出应用程序时。我希望停止退出应用程序，直到用户按下yes按钮。如果用户按否，则返回应用程序

Answer 1

有两件事可以实现

<强> 1）。

stopService(new Intent(this, BackServices.class));
                finish();

从此处删除finish();，因为这是您的活动关闭的原因

2。）而不是

return super.onKeyDown(keyCode, event);

你可以像这样返回假，

  return false;

Answer 2

我的方法就是这样，

    public void onBackPressed() {
    //finish();
     AlertDialog.Builder alertbox = new AlertDialog.Builder(this);
     alertbox.setTitle("Warning");
     alertbox.setMessage("Exit Application?");
     alertbox.setPositiveButton("Yes", new
     DialogInterface.OnClickListener() {
     public void onClick(DialogInterface arg0, int arg1) {
     finish();
     }
     });
     alertbox.setNegativeButton("No", new
     DialogInterface.OnClickListener() {
     public void onClick(DialogInterface arg0, int arg1) {

     }
     });
     alertbox.show();
}

或者考虑一下你自己的代码，我可能会做这样的事情。

你必须在像这样的正面按钮点击事件中提供finish（），

public boolean onKeyDown(int keyCode, KeyEvent event) {
    if ((keyCode == KeyEvent.KEYCODE_BACK)) {
        try {
              AlertDialog.Builder alertbox = new AlertDialog.Builder(this);
                alertbox.setMessage("This is the alertbox!");
                alertbox.setPositiveButton("Yes", new DialogInterface.OnClickListener() {


                    public void onClick(DialogInterface arg0, int arg1) {
                        Toast.makeText(getApplicationContext(), "'Yes' button clicked", Toast.LENGTH_SHORT).show();
         stopService(new Intent(this, BackServices.class));
                              finish();
                    }
                });

                // set a negative/no button and create a listener
                alertbox.setNegativeButton("No", new DialogInterface.OnClickListener() {


                    public void onClick(DialogInterface arg0, int arg1) {
                        Toast.makeText(getApplicationContext(), "'No' button clicked", Toast.LENGTH_SHORT).show();
                    }
                });

                alertbox.show();


        } catch (Exception e) {
            // TODO: handle exception
        }
    }
    return super.onKeyDown(keyCode, event);
}

Answer 3

Keep your code as it is...with adding finish() call in positive button click
And override onBackPressed() method with doing nothin

public void onBackPressed() {

}

public boolean onKeyDown(int keyCode, KeyEvent event) {
    if ((keyCode == KeyEvent.KEYCODE_BACK)) {
        try {
              AlertDialog.Builder alertbox = new AlertDialog.Builder(this);
                alertbox.setMessage("This is the alertbox!");
                alertbox.setPositiveButton("Yes", new DialogInterface.OnClickListener() {


                    public void onClick(DialogInterface arg0, int arg1) {
                        Toast.makeText(getApplicationContext(), "'Yes' button clicked", Toast.LENGTH_SHORT).show();
         stopService(new Intent(this, BackServices.class));
                              finish();
                    }
                });

                // set a negative/no button and create a listener
                alertbox.setNegativeButton("No", new DialogInterface.OnClickListener() {


                    public void onClick(DialogInterface arg0, int arg1) {
                        Toast.makeText(getApplicationContext(), "'No' button clicked", Toast.LENGTH_SHORT).show();
                    }
                });

                alertbox.show();


        } catch (Exception e) {
            // TODO: handle exception
        }
    }
    return super.onKeyDown(keyCode, event);
}

Answer 4

更好的解决方案是返回true以表明您已经消耗了该事件。

public boolean onKeyDown(int keyCode, KeyEvent event) {
    if ((keyCode == KeyEvent.KEYCODE_BACK)) {
        // do your stuff
        ....
        ....
        return true;  // control will return from here. super will not be called.
    }
    return super.onKeyDown(keyCode, event);
}

AlertBox在Android中重新按下

4 个答案: