Trying to use the upload/progress in radzen ide...any ideas?

using Radzen's ide I created a new page, dropped an upload control and a progress bar onto my new page. When running it in VS2019 we get an error:
Failed to load resource: the server responded with a status of 400 (Bad Request) [http://localhost:5000/UploadAttachment/Single]
The program '' has exited with code -1 (0xffffffff).

The documentation isn't clear on it when you're not in vs2019 and are in radzen especially since we don't use the razor/blazor page @code we're using what radzen generates for us in vs2019.

You need to find what is causing the exception. Check Radzen's output pane or use Visual Studio to debug the application.

I added via nuget package manager the Radzen.Blazor
in _Imports.razor I added
@using Radzen
@using Radzen.Blazor
in my page
I added
@using Microsoft.JSInterop


Manual Upload

OnChange(args, "Manual Upload")) Progress=@(args => OnProgress(args, "Manual Upload")) />
RUupload.Upload()) Style="margin-bottom: 20px;" />
in the code block I added:

@code {
EventConsole console;

RadzenUpload RUupload;

int progress;
string info;

int customParameter = 1;

void OnChange(UploadChangeEventArgs args, string name)
    foreach (var file in args.Files)
        console.Log($"File: {file.Name} / {file.Size} bytes");

    console.Log($"{name} changed");

void OnProgress(UploadProgressArgs args, string name)
{ = $"% '{name}' / {args.Loaded} of {args.Total} bytes.";
    this.progress = args.Progress;

    if (args.Progress == 100)

        foreach (var file in args.Files)
            console.Log($"Uploaded: {file.Name} / {file.Size} bytes");

void OnComplete(UploadCompleteEventArgs args)
    console.Log($"Server response: {args.RawResponse}");


Visual studio is complaining about the code block, and specifically
EventConsole console;

I'm using vs 2019, .net 5, radzen ide primarily for scaffolding purposes

in error list I get:

Severity Code Description Project File Line Suppression State
Error CS0246 The type or namespace name 'EventConsole' could not be found (are you missing a using directive or an assembly reference?) TestUploadComponent.Client C:\Users\rwdevalcourt\source\repos\TestUploadComponent\TestUploadComponent\Client\Pages\Upload.razor 20 Active

This is not part of the NuGet package:

@enchev @korchev
I was able to add a razor component named EventConsole and copy/paste the code from your radzen-blazor demo project.

Testing it now!

In OnProgress
where do you specify the upload file put it here location? I realize that it is on a server and I'll need to get to the bytes held by the file on the server to store elsewhere.

I have OnProgress, OnChange, and OnComplete in the razor page @code {}

However I also need to have it hit the UploadController like shown in:

Upload component (

if you set a break point in UploadController it never hits it o.O

btw I created a blazor server app with .net 6.0

Here is a sample project that shows how to do that. (25.1 KB)

It uses two page properties progress and progressVisible:

Those are set in the Progress and Complete events of RadzenUpload:

We got it working. we had a controller and we used the upload/{id} from the online example.