我使用了AlertDialog,但它只在APP打开时显示对话框。
如果APP在后台运行,则AlertDialog不会显示在顶部。
例如,时钟APP。
当时间到了,它会在顶部显示对话框或提示窗口。
当APP在后台运行时如何在顶部显示对话框???
答案 0 :(得分:1)
您可以在应用处于后台时显示系统级警报。请考虑使用以下代码来显示此类警报。
WindowManager wm = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
WindowManager.LayoutParams params = new WindowManager.LayoutParams(
WindowManager.LayoutParams.MATCH_PARENT,
WindowManager.LayoutParams.MATCH_PARENT,
WindowManager.LayoutParams.TYPE_SYSTEM_ALERT
| WindowManager.LayoutParams.TYPE_SYSTEM_OVERLAY,
WindowManager.LayoutParams.FLAG_NOT_TOUCH_MODAL
| WindowManager.LayoutParams.FLAG_NOT_FOCUSABLE,
PixelFormat.TRANSPARENT);
params.height = WindowManager.LayoutParams.MATCH_PARENT;
params.width = WindowManager.LayoutParams.MATCH_PARENT;
params.format = PixelFormat.TRANSLUCENT;
params.gravity = Gravity.TOP;
LinearLayout ly = new LinearLayout(context);
ly.setBackgroundColor(Color.BLACK);
ly.setOrientation(LinearLayout.VERTICAL);
ImageView iv = new ImageView(context);
iv.setImageResource(R.drawable.ic_launcher);
ly.addView(iv);
TextView tv1 = new TextView(context);
tv1.setWidth(params.width);
tv1.setBackgroundColor(Color.BLUE);
ly.addView(tv1);
wm.addView(ly, params);
在清单中添加权限
uses-permission android:name =“android.permission.SYSTEM_ALERT_WINDOW”
答案 1 :(得分:0)
我知道回复有点迟,但由于没有接受答案,你可以考虑这个。
您不必为窗口创建和添加自定义视图。如果您的目标是只显示常规对话框,则可以执行以下操作。
创建一个Service类,让应用程序通过将其写入AndroidManifest.xml来了解该服务。喜欢的东西;
<service android:name="your.package.name.PopupService"/>
然后实施服务;
public class PopupService extends Service {
private Intent myIntent;
MaterialDialog dialog;
@Override
public IBinder onBind(Intent intent) {
return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId) {
this.myIntent = intent;
showDialog(myIntent.getStringExtra("msg")); // you can send extra information to service via intent
return super.onStartCommand(intent, flags, startId);
}
@Override
public void onCreate() {
super.onCreate();
}
private void showDialog(String message)
{
if (dialog != null) {
if (dialog.isShowing()) {
dialog.dismiss();
}
}
dialog = new MaterialDialog.Builder(getApplicationContext())
.content(message)
.positiveText("OK")
.negativeText("cancel")
.positiveColor(getResources().getColor(R.color.colorAccent))
.negativeColor(getResources().getColor(R.color.colorPrimary))
.cancelable(true)
.callback(new MaterialDialog.ButtonCallback() {
@Override
public void onPositive(MaterialDialog dialog) {
stopSelf();
}
@Override
public void onNegative(MaterialDialog dialog) {
stopSelf();
}
})
.dismissListener(new DialogInterface.OnDismissListener() {
@Override
public void onDismiss(DialogInterface dialog) {
stopSelf();
}
})
.build();
dialog.getWindow().setType(WindowManager.LayoutParams.FLAG_SHOW_WHEN_LOCKED
| WindowManager.LayoutParams.FLAG_DISMISS_KEYGUARD
| WindowManager.LayoutParams.FLAG_TURN_SCREEN_ON);
dialog.show();
}
@Override
public void onDestroy() {
if (dialog != null) {
dialog.dismiss();
}
super.onDestroy();
}
}
当您想要显示对话框时,只需调用服务,例如;
Intent intent = new Intent(MainActivity.this, PopupService.class);
intent.putExtra("msg","Test Message");
startService(intent);
还有一件事,就是将此权限添加到AndroidManifest.xml
<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>
希望这会有所帮助:)