doc: add asynchronous operation function to the VAT invoice upload button (#332)

Author: ArgoZhang

src/BootstrapBlazor.Shared/Demos/BaiduOcr/BaiduOcrNormal.razor

@@ -1,7 +1,8 @@
 @inject IBaiduOcr OcrService
 @inject ToastService ToastService
+@implements IDisposable
 
-<ButtonUpload TValue="string" OnChange="@OnClickToUpload" BrowserButtonText="VATInvoice" ShowUploadFileList="false"></ButtonUpload>
+<ButtonUpload TValue="string" OnChange="@OnClickToUploadBlock" BrowserButtonText="VATInvoice" ShowUploadFileList="false" IsDisabled="IsLoading" BrowserButtonIcon="@Icon"></ButtonUpload>
 
 @if (Invoice != null)
 {
@@ -107,4 +108,79 @@
             }
         }
     }
+
+    /*以下示例为本站特殊处理逻辑可不参考*/
+    private bool IsLoading { get; set; }
+
+    private string ButtonIcon { get; } = "fa-solid fa-cloud-arrow-up";
+
+    private string LoadingIcon { get; } = "fa-solid fa-spinner fa-spin-pulse";
+
+    private string Icon => IsLoading ? LoadingIcon : ButtonIcon;
+
+    /// <summary>
+    /// 取消请求令牌
+    /// </summary>
+    private CancellationTokenSource? TokenSource { get; set; }
+
+    private async Task OnClickToUploadBlock(UploadFile file)
+    {
+        if (file.File != null)
+        {
+            // 设置 按钮禁用
+            IsLoading = true;
+            StateHasChanged();
+
+            // 获得上传文件
+            var payload = await file.GetBytesAsync(file.File.Size);
+            if (payload?.Any() ?? false)
+            {
+                try
+                {
+                    TokenSource ??= new();
+                    var result = await OcrService.CheckVatInvoiceAsync(payload, TokenSource.Token);
+                    Invoice = result.Entity;
+                    if (result.Entity != null)
+                    {
+                        await ToastService.Success("Vat Invoice", "VAT Invoice success!");
+                    }
+                    else
+                    {
+                        await ToastService.Information("Vat Invoice", $"{result.ErrorCode}: {result.ErrorMessage}");
+                    }
+                }
+                catch (TaskCanceledException)
+                {
+
+                }
+            }
+
+            IsLoading = false;
+            StateHasChanged();
+        }
+    }
+
+    /// <summary>
+    /// 关闭网页时调用
+    /// </summary>
+    /// <param name="disposing"></param>
+    /// <returns></returns>
+    protected virtual void Dispose(bool disposing)
+    {
+        if (disposing && TokenSource != null)
+        {
+            TokenSource.Cancel();
+            TokenSource.Dispose();
+        }
+    }
+
+    /// <summary>
+    /// 关闭网页时调用
+    /// </summary>
+    /// <returns></returns>
+    public void Dispose()
+    {
+        Dispose(true);
+        GC.SuppressFinalize(this);
+    }
 }