在android中显示来自非活动类的对话框警报 [英] Show dialog alert from a non-activity class in android

问题描述

我想通过 AlertDialogManager 类向 non-activity 类显示一个警报对话框 DeviceAdminReceiverSample 的方法 onDisabled，但是每当我通过该方法调用 alertDialog 时，它都会生成带有以下文本的错误

I want to show an Alert Dialog via AlertDialogManager class to a non-activity class DeviceAdminReceiverSample's method onDisabled, but whenever I call alertDialog via that method it generates error with following text

错误

06-12 12:01:19.923: E/AndroidRuntime(468): FATAL EXCEPTION: main
06-12 12:01:19.923: E/AndroidRuntime(468): java.lang.RuntimeException: Unable to start           
receiver com.android.remotewipedata.DeviceAdminReceiverSample:   
android.view.WindowManager$BadTokenException: Unable to add window -- token null is not   
for an application

我知道问题出在 context 的事情上，但我不知道该放什么才能让它工作，我尝试了 this, getApplicationContext() 但都是徒劳的.我的两个类的代码如下

I know the issue is with context thing but I don't know what to put there so that it work, I tried this, getApplicationContext() but all vain. My code for both classes is below

AlertDialogManager

public class AlertDialogManager {

public void showAlertDialog(Context context, String title, String message,
        Boolean status) {
    final AlertDialog alertDialog = new AlertDialog.Builder(context).create();
    alertDialog.setTitle(title);
    alertDialog.setMessage(message);

    if (status != null)
        alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                alertDialog.dismiss();
            }
        });
    alertDialog.show();
}

}

DeviceAdminReceiverSample

public class DeviceAdminReceiverSample extends DeviceAdminReceiver {
static final String TAG = "DeviceAdminReceiver";
AlertDialogManager alert = new AlertDialogManager();

/** Called when this application is no longer the device administrator. */
@Override
public void onDisabled(Context context, Intent intent) {
    super.onDisabled(context, intent);
    Toast.makeText(context, R.string.device_admin_disabled,
            Toast.LENGTH_LONG).show();
    // intent.putExtra("dialogMessage", "Device admin has been disabled");
    // intent.setClass(context, DialogActivity.class);
    // intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    // context.startActivity(intent);
    alert.showAlertDialog(context, "Alert",
            "Device admin has been disabled", true);
}

推荐答案

问题是您只能显示来自活动的 AlertDialogs".这不是上下文问题.

The problem is 'You can show AlertDialogs from Activity only'. This is not an issue of context.

虽然这不是一个好主意，显示来自接收者的对话(最好使用通知)，但如果你想这样做，你可以创建一个活动作为对话和显示

这篇关于在android中显示来自非活动类的对话框警报的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！