Question

我需要在后台服务中提示alertDialog，但是由于错误的上下文而崩溃，我该如何处理它，哪里可以获得正确的上下文？

Answer 1

服务类内的代码打开AlertDialog

private void showAlertDialog() {

        KeyguardManager km = (KeyguardManager) getSystemService(Context.KEYGUARD_SERVICE);
        KeyguardManager.KeyguardLock kl = km.newKeyguardLock("MyKeyguardLock");
            kl.disableKeyguard();

            PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
            WakeLock wakeLock = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK| PowerManager.ACQUIRE_CAUSES_WAKEUP
                    | PowerManager.ON_AFTER_RELEASE, "MyWakeLock");
            wakeLock.acquire();


        final CharSequence[] items = { getString(R.string.test1), getString(R.string.tes2), getString(R.string.test3), getString(R.string.cancel) };
        AlertDialog.Builder builder = new AlertDialog.Builder(getApplicationContext());
        builder.setTitle("Title");
        builder.setItems(items, new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int item) {
                if (items[item].equals(getString(R.string.test1))) {
                    dialog.dismiss();

                } else if (items[item].equals(getString(R.string.test2))) {
                    dialog.dismiss();

                } else if (items[item].equals(getString(R.string.test3))) {

                }else if (items[item].equals(getString(R.string.cancel))) {
                    dialog.dismiss();


                }
            }
        });

        alert = builder.create();
        alert.getWindow().setType(WindowManager.LayoutParams.TYPE_SYSTEM_ALERT);
        alert.getWindow().addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON|
                WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD|
                WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED|
                WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);


        alert.show();

        alert.setOnDismissListener(new OnDismissListener() {

            @Override
            public void onDismiss(DialogInterface arg0) {

            }
        });


        alert.setOnCancelListener(new OnCancelListener() {

            @Override
            public void onCancel(DialogInterface dialog) {

            }
        });


    }

您必须在清单文件中添加权限

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

您可以根据需要在警告对话框中执行自定义。

完成

Answer 2

接受的答案在Oreo +中不起作用请在WindowManager.LayoutParams中使用标志TYPE_APPLICATION_OVERLAY而不是TYPE_PHONE或SYSTEM_ALERT：使用

WindowManager.LayoutParams.TYPE_APPLICATION_OVERLAY

代替

WindowManager.LayoutParams.TYPE_SYSTEM_ALERT

Answer 3

1，您必须设置：mDialog.getWindow().setType( WindowManager.LayoutParams.TYPE_SYSTEM_ALERT); 2，设置权限：

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

如何在后台服务中使用alertDialog

3 个答案: