Blazor Barcode Scanner Tutorial Using IronBarcode

    <script src="webcam.js"></script>

    // current video stream
    let videoStream;
    async function initializeCamera() 
    {
        const canvas = document.querySelector("#canvas");
        const video = document.querySelector("#video");
        if (
            !"mediaDevices" in navigator ||
            !"getUserMedia" in navigator.mediaDevices
            )
            {
                alert("Camera API is not available in your browser");
                return;
            }

        // video constraints
        const constraints = {
            video: {
                width: {
                    min: 180
                },
                height: {
                    min: 120
                },
            },
        };

        constraints.video.facingMode = useFrontCamera ? "user" : "environment";

        try {
                videoStream = await navigator.mediaDevices.getUserMedia (constraints);    
                video.srcObject = videoStream;
            } 
            catch (err) 
            {
                alert("Could not access the camera" + err);
            }
    }

' current video stream
	Private videoStream As let
	Async Function initializeCamera() As [function]
		const canvas = document.querySelector("#canvas")
		const video = document.querySelector("#video")
		If (Not "mediaDevices") in navigator OrElse (Not "getUserMedia") in navigator.mediaDevices Then
				alert("Camera API is not available in your browser")
				Return
		End If

		' video constraints
		const constraints = {
			video: {
				width: { min: 180 },
				height: { min: 120 }
			}
		}

		constraints.video.facingMode = If(useFrontCamera, "user", "environment")

		Try
				videoStream = Await navigator.mediaDevices.getUserMedia(constraints)
				video.srcObject = videoStream
			Catch e1 As err
				alert("Could not access the camera" & err)
			End Try
	End Function

    protected override async Task OnInitializedAsync()
    {
        await JSRuntime.InvokeVoidAsync("initializeCamera");
    }

Protected Overrides Async Function OnInitializedAsync() As Task
		Await JSRuntime.InvokeVoidAsync("initializeCamera")
End Function

    <section class="section">
        <video autoplay id="video" width="320"></video>
    </section>

function getFrame(dotNetHelper) 
{
    canvas.width = video.videoWidth;
    canvas.height = video.videoHeight;
    canvas.getContext('2d').drawImage(video, 0, 0);
    let dataUrl = canvas.toDataURL("image/png");
    //Invoke ProcessImage Function and send DataUrl as a parameter to it 
    dotNetHelper.invokeMethodAsync('ProcessImage', dataUrl);
}

    [JSInvokable]
    public async void ProcessImage(string imageString)
    {

        var imageObject = new CamImage();
        imageObject.imageDataBase64 = imageString;
        var jsonObj = System.Text.Json.JsonSerializer.Serialize(imageObject);
        //Do image processing here
        var barcodeeResult = await Http.PostAsJsonAsync($"Ironsoftware/ReadBarCode", imageObject);
        if (barcodeeResult.StatusCode == System.Net.HttpStatusCode.OK)
        {
            QRCodeResult = barcodeeResult.Content.ReadAsStringAsync().Result;
            StateHasChanged();
        }
    }

<JSInvokable>
Public Async Sub ProcessImage(ByVal imageString As String)

		Dim imageObject = New CamImage()
		imageObject.imageDataBase64 = imageString
		Dim jsonObj = System.Text.Json.JsonSerializer.Serialize(imageObject)
		'Do image processing here
		Dim barcodeeResult = Await Http.PostAsJsonAsync($"Ironsoftware/ReadBarCode", imageObject)
		If barcodeeResult.StatusCode = System.Net.HttpStatusCode.OK Then
			QRCodeResult = barcodeeResult.Content.ReadAsStringAsync().Result
			StateHasChanged()
		End If
End Sub

    private async Task CaptureFrame()
    {
        await JSRuntime.InvokeAsync<String>("getFrame", DotNetObjectReference.Create(this));
    }

Private Async Function CaptureFrame() As Task
		Await JSRuntime.InvokeAsync(Of String)("getFrame", DotNetObjectReference.Create(Me))
End Function

    [HttpPost]
    [Route("ReadBarCode")]
    public string ReadBarCode(CamImage imageData)
    {
        try
            {
                var splitObject = imageData.imageDataBase64.Split(',');
                byte[] imagebyteData = Convert.FromBase64String((splitObject.Length > 1) ? splitObject[1] : splitObject[0]);
                IronBarCode.License.LicenseKey = "Key";

                using (var ms = new MemoryStream(imagebyteData))
                {
                    Image barcodeImage = Image.FromStream(ms);
                    var result = IronBarCode.BarcodeReader.QuicklyReadOneBarcode(barcodeImage);
                    if (result == null || result.Value == null)
                    {
                        return $"{DateTime.Now} : Barcode is Not Detetced";
                    }

                    return $"{DateTime.Now} : Barcode is ({result.Value})";
                }

            }
        catch (Exception ex)
            {
                return $"Exception is {ex.Message}";
            }
    }

    //Post Object 
    public class CamImage
    {
        public string imageDataBase64 { get; set; }
    }

<HttpPost>
<Route("ReadBarCode")>
Public Function ReadBarCode(ByVal imageData As CamImage) As String
		Try
				Dim splitObject = imageData.imageDataBase64.Split(","c)
				Dim imagebyteData() As Byte = Convert.FromBase64String(If(splitObject.Length > 1, splitObject(1), splitObject(0)))
				IronBarCode.License.LicenseKey = "Key"

				Using ms = New MemoryStream(imagebyteData)
					Dim barcodeImage As Image = Image.FromStream(ms)
					Dim result = IronBarCode.BarcodeReader.QuicklyReadOneBarcode(barcodeImage)
					If result Is Nothing OrElse result.Value Is Nothing Then
						Return $"{DateTime.Now} : Barcode is Not Detetced"
					End If

					Return $"{DateTime.Now} : Barcode is ({result.Value})"
				End Using

		Catch ex As Exception
				Return $"Exception is {ex.Message}"
		End Try
End Function

	'Post Object 
	Public Class CamImage
		Public Property imageDataBase64() As String
	End Class