Hook up disposing events and remove listeners on dispose

sabitertan · Feb 24, 2023 · c978307 · c978307
1 parent 604e0d8
commit c978307
Showing 1 changed file with 20 additions and 3 deletions.
diff --git a/BlazorBarcodeScanner.ZXing.JS/BarcodeReader.razor.cs b/BlazorBarcodeScanner.ZXing.JS/BarcodeReader.razor.cs
@@ -120,6 +120,9 @@ protected override async Task OnAfterRenderAsync(bool firstRender)
 
                     BarcodeReaderInterop.BarcodeReceived += ReceivedBarcodeText;
                     BarcodeReaderInterop.ErrorReceived += ReceivedErrorMessage;
+                    BarcodeReaderInterop.DecodingStarted += DecodingStarted;
+                    BarcodeReaderInterop.DecodingStopped += DecodingStopped;
+
                     if (StartCameraAutomatically && _videoInputDevices.Count > 0)
                     {
                         await _backend.SetVideoInputDevice(SelectedVideoInputId);
@@ -136,13 +139,18 @@ protected override async Task OnAfterRenderAsync(bool firstRender)
         [Obsolete("Please use DisposeAsync")]
         public void Dispose()
         {
-            StopDecoding();
+            DisposeAsync();
         }
         public async ValueTask DisposeAsync()
         {
             try
             {
                 await StopDecoding();
+
+                BarcodeReaderInterop.BarcodeReceived -= ReceivedBarcodeText;
+                BarcodeReaderInterop.ErrorReceived -= ReceivedErrorMessage;
+                BarcodeReaderInterop.DecodingStarted -= DecodingStarted;
+                BarcodeReaderInterop.DecodingStopped -= DecodingStopped;
             }
             catch (Exception ex)
             {
@@ -170,7 +178,6 @@ public async Task StartDecoding()
             var height = StreamHeight ?? 0;
             await _backend.StartDecoding(_video, width, height);
             SelectedVideoInputId = await _backend.GetVideoInputDevice();
-            IsDecoding = true;
             StateHasChanged();
         }
 
@@ -200,7 +207,6 @@ public async Task StopDecoding()
         {
             BarcodeReaderInterop.OnBarcodeReceived(string.Empty);
             await _backend.StopDecoding();
-            IsDecoding = false;
             StateHasChanged();
         }
 
@@ -266,6 +272,17 @@ private async Task ReceivedErrorMessage(ErrorReceivedEventArgs args)
             StateHasChanged();
         }
 
+        private Task DecodingStarted(DecodingActionEventArgs _)
+        {
+            IsDecoding = true;
+            return Task.CompletedTask;
+        }
+        private Task DecodingStopped(DecodingActionEventArgs _)
+        {
+            IsDecoding = false;
+            return Task.CompletedTask;
+        }
+
         protected async Task ChangeVideoInputSource(string deviceId)
         {
             SelectedVideoInputId = deviceId;