android - 在 android 中显示来自非 Activity 类的对话框警报

Question

我想通过 AlertDialogManager 显示一个警告对话框类到 non-activity类 DeviceAdminReceiverSample的方法 onDisabled , 但每当我调用 alertDialog通过该方法，它会生成带有以下文本的错误

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 上东西，但我不知道该放什么让它起作用，我试过了 this , getApplicationContext()但都是徒劳的。我对这两个类的代码如下

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);
}

Answer 1

只需在您的alertDialog.show();

之前添加

alertDialog.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);

如果上述方法无效，请尝试以下操作:

alertDialog.getWindow().setType(WindowManager.LayoutParams.TYPE_APPLICATION_PANEL); 

并使用此权限:

<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />