Currently, what I did is to access the camera and use it to take a picture, but this isn't exactly what I want to accomplish.
I want to activate and display front camera preview on my content page, and then take a picture by pressing a button control.
I've searched around and I can't seem to find any solution. In Xamarin, there's CameraView from Xamarin Community Toolkit that can be used for camera stream, but from the looks of it, CameraView hasn't been implemented in .NET MAUI Community Toolkit. Is there any other way to do this? Thank you.
This is the code for the button event
private async void takephoto(object sender, EventArgs e)
{
if (MediaPicker.Default.IsCaptureSupported)
{
FileResult photo = await MediaPicker.Default.CapturePhotoAsync();
if (photo != null)
{
// save the file into local storage
string localFilePath = Path.Combine(FileSystem.CacheDirectory, photo.FileName);
using Stream sourceStream = await photo.OpenReadAsync();
Stream stream = await photo.OpenReadAsync();
using FileStream localFileStream = File.OpenWrite(localFilePath);
await sourceStream.CopyToAsync(localFileStream);
DisplayPhoto.Source = ImageSource.FromStream(() =>
{
return stream;
});
}
}
}
clientViaUserConsent opens URL in browser but it said invalid request. this URL is generated internally from lib. I had double-checked my ClientId for both platforms but still face issues for getting AuthClient for create a calendar event.
I used the below packages to create events in the google calender.
googleapis: ^8.1.0
googleapis_auth: ^1.3.0
static final androidClientId = ClientId('xxxxxxxx.apps.googleusercontent.com');
static final iOSClientId = ClientId('xxxxxxx.apps.googleusercontent.com');
final _clientID = Platform.isAndroid ? EventProvider.androidClientId : EventProvider.iOSClientId;
final _scopes = [CalendarApi.calendarScope];
clientViaUserConsent(_clientID, _scopes, prompt).then((AuthClient client) {
var calendar = CalendarApi(client);
}
void prompt(String url) async {
print(" => $url");
if (await canLaunch(url)) {
await launch(URL);
} else {
throw 'Could not launch $url';
}
}
I am referring to this article for creating an event in google calendar.
https://blog.codemagic.io/google-meet-events-in-flutter/
https://medium.com/flutter-community/flutter-use-google-calendar-api-adding-the-events-to-calendar-3d8fcb008493
You are seeing that error because the app hasn't been verified. If you are the app developer I advise you to check the App Verification FAQ to learn more about the verification steps. If you aren't the developer, you could try to enable the less secure app access but please be mindful of the consequences:
Less secure apps can make it easier for hackers to get in to your account, so blocking sign-ins from these apps helps keep your account safe.
I'm using SignalR for push notifications on my Flutter app and that works ok. I get the message from the backend and show notification using flutter_local_notifications. The problem is that the SignalR service would shut down after some time.
How can I make my app stay on in the background? and even start on reboot?
Here's my code:
import 'dart:async';
import 'dart:convert';
import 'package:flutter/material.dart';
import 'package:isolate_test/Model/UserMessageModel.dart';
import 'package:signalr_core/signalr_core.dart';
import 'EndPointService.dart';
import 'NotificationService.dart';
class SignalRProvider {
static String appName = "NOTIFICATION";
static String? userName = "";
static String deviceName = "android_app";
static List<UserMessageModel> messages = <UserMessageModel>[];
HubConnection connection = HubConnectionBuilder()
.withUrl(
'my_url',
HttpConnectionOptions(
logging: (level, message) => print(message),
))
.withAutomaticReconnect()
.withHubProtocol(JsonHubProtocol())
.build();
Function(bool update)? onMessagesUpdateCallback;
SignalRProvider({
this.onMessagesUpdateCallback,
});
setUsername(String username) {
userName = username;
}
Future initSignalR(BuildContext context) async {
WidgetsFlutterBinding.ensureInitialized();
await NotificationService().init();
connection.on('SignalRUserReceiveMessage', (message) async {
var data = message!.first;
if (data != null) {
UserMessageModel msg = UserMessageModel.fromJson(data);
messages.add(msg);
msg.showNotification();
}
if (onMessagesUpdateCallback != null) {
onMessagesUpdateCallback!(true);
}
});
connection.on('SignalRMonitoringMessage', (message) async {
var data = message!.first;
if (data != null) {
UserMessageModel msg = UserMessageModel.fromJson(data);
messages.add(msg);
msg.showNotification();
}
if (onMessagesUpdateCallback != null) {
onMessagesUpdateCallback!(true);
}
});
connection.on("SignalRReceiveConnectedMessage", (message) async {
await connection.send(methodName: 'SignalRInit', args: [
userName,
appName,
connection.connectionId,
]);
});
connection.on("SignalRReceiveDisconnectedMessage", (message) async {
if (connection.state == HubConnectionState.disconnected) {
connection.start();
}
});
await connection.start();
}
List<UserMessageModel> getMessages() {
return messages;
}
Future deleteMessage(UserMessageModel _msg) async {
if (_msg == null) return;
var response =
await EndPointService().SetupApi("Message", "", []).httpDelete(
HeaderEnum.BasicHeaderEnum,
ResponseEnum.ResponseModelEnum,
jsonEncode(_msg),
);
}
addOrUpdateMessage(UserMessageModel _msg) {
if (_msg == null) return;
if (messages != null) {
var found =
messages.firstWhere((e) => e.user == _msg.user && e.id == _msg.id);
var index =
messages.indexWhere((e) => e.user == _msg.user && e.id == _msg.id);
if (found != null) {
messages[index] = _msg;
} else {
messages.add(_msg);
}
if (onMessagesUpdateCallback != null) {
onMessagesUpdateCallback!(true);
}
}
}
setMessagesUpdateCallback(Function(bool update) func) {
onMessagesUpdateCallback = func;
}
}
SignalR problems
SignalR for Flutter uses web sockets and SSE to receive messages from the SignalR service. If the app was terminated because the user restarted their phone or the OS shut down the app to save battery, these push notifications would not be received by the app.
To overcome this, app developers (and SignalR) have to use FCM on Android, and APNs on iOS (or FCM which will also use APNs on iOS). All other approaches will be more limited because the operating systems do not allow users to keep background processes running the entire time. This was actually allowed years ago, but the operating systems have made these changes to save the user battery - they enforce that all apps go through the same push notification medium - FCM on Android, APNs on iOS.
SignalR for Flutter uses neither FCM nor APNs. At it's current state, SignalR is not well suited for Android or iOS - take a look at the comments with people struggling with similar problems to you on How to use signalr in Android.
Alternative solution
The simplest / easiest way to get started is to use Firebase Cloud Messaging.
On Android, it will be used directly to send messages to devices, and
on iOS, FCM will use APNs to reach devices reliably
Caveat: On Android, there is a more complicated alternative called unifiedpush, but the limitations include showing a notification to the user at all times to handle background notifications.
My analysis: This is all done based on my quick investigation by reading the pubspec.yaml, the GitHub issues on the original repo, the SignalR documentation, and some experience implementing Push Notifications for Flutter.
Disclosure: I just released a push notification library 2 days ago called push which would be well suited to these types of Push Notification packages making the transformation to using FCM on Android and APNs on iOS. However, as an app developer, in most cases, you should use firebase_messaging, not push.
I worked with SignalR but on native Platform(IOS & Android), I made stock app and get realtime price. When app go to background, I will disconnect with SignalR server after 5 second, and when app go to foreground again, I check if app's current state not connect to server SignalR, I'll connect again. I think it not good if your app still connect and receiver data from signalR server in background state.
I'm making a Flutter Web App which has to access the microphone and streams the audio data as an array of integers for further processing.
I already succeeded doing this in plain JavaScript.
Things I've tried:
The flutter_sound library, but I couldn't get it to work. I also can't find any working examples for that library.
dart:web_audio seems to be a thing, but apparently you can't even import it yet in normal Flutter Apps.
dart:js is what im trying to do right now. I was able to create an AudioContext with var audioContext = JsObject(context['AudioContext']);. However, after that I dont know what syntax can be used to transfer the JavaScript code into Dart. Here is what I'm doing in JavaScript:
function initAudio() {
try {
audioCtx = new AudioContext();
const GotAudioStream = function(stream) {
const audioSource = audioCtx.createMediaStreamSource(stream);
const audioProcessor = audioCtx.createScriptProcessor(bufSize, 1, 1);
audioSource.connect(audioProcessor);
audioProcessor.connect(audioCtx.destination);
audioStarted = true;
audioProcessor.onaudioprocess = function(e) {
checkAudioBuffer(e.inputBuffer);
};
};
navigator.mediaDevices.getUserMedia({ audio: true, video: false }).then(GotAudioStream);
}
catch (err) {
console.log(err);
}
}
Does anyone have experience with the dart:js library or another Idea on how to implement a simple (live!) audio stream in Flutter Web?
Regards,
Kaisky
I'm trying to send a message to multiple phone numbers via WhatsApp using Flutter:
sendMessage() async {
var number = ["201020402642", "201030666895"];
var baseUrl = "https://api.whatsapp.com/send/";
var urlIos = "";
number.forEach((element) async {
var url = baseUrl +"?phone=${element} &text=msg";
if (await canLaunch(url)) {
await launch(url);
} else {
print("not installed");
}
});
}
It only sends a message to the last number.
Is there a way to send a message to a group of numbers?
Unfortunately, there's no way to send a message for more than 1 number at the same time using deep links. The only way you can do something like this is by using the WhatsApp business API through REST requests. There are some third-party software with this feature like https://www.twilio.com/whatsapp
Here is the WhatsApp API doc
https://developers.facebook.com/docs/whatsapp/api/messages/#sending-messages