FileUploadStartEventArgs.Cancel Property

Specifies whether the file upload operation should be canceled.

Assembly : DevExpress.Blazor.v25.2.dll

Declaration

csharp

public bool Cancel { get; set; }

Property Value

Type	Description
Boolean

true to cancel file upload; otherwise, false.

Remarks

Handle the FileUploadStart event to control file upload before it is started. Use the event argument’s FileInfo property to get information about the file (its name, type, size, and so on). Set the event argument’s Cancel property to true to cancel file upload.

The following snippet prohibits upload of files whose size exceeds 1MB.

Razor
UploadController

razor

<DxUpload Name="myFile" UploadUrl="https://localhost:10000/api/Upload/Upload/" 
          FileUploadStart="@OnFileUploadStart">
</DxUpload>

@code {
    void OnFileUploadStart(FileUploadStartEventArgs e) {
        if (e.FileInfo.Size > 1048576)
            e.Cancel = true;
    }
}

csharp

using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;

namespace BlazorDemo.AspNetCoreHost;
[Route("api/[controller]")]
[ApiController]
public class UploadController : ControllerBase {
    [HttpPost("[action]")]
    public ActionResult Upload(IFormFile myFile) {
        try {
            // Write code that saves the 'myFile' file.
            // Don't rely on or trust the FileName property without validation.
        } catch {
            return BadRequest();
        }
        return Ok();
    }
}