Blazor Server Side实现图片验证码 [Asp.Net Core]用Blazor Server Side实现图片验证码

@page "/BlazorVerificationCode"

<p>
 (Blazor) A sample for how to show verification code and verify it.
</p>

@inject IJSRuntime jsr

@{
 if (imgurl == null) MakeNewImage();
}

<img style="border:solid 1px #ccc" src="@imgurl" />
<button @onclick="MakeNewImage">Renew</button>
<hr />
<div>Type the number in image</div>
<EditForm Model="this" OnSubmit="DoCheck">
 <input type="text" @bind-value="inp_code" style="padding:5px" />
 <button>Check</button>
</EditForm>

@code{
 string inp_code;
 string vericode;
 string imgurl;

 void DoCheck()
 {
  string msg = "You typed a wrong value";
  if (inp_code == vericode)
   msg = "Yes the number is " + vericode;
  jsr.InvokeAsync<object>("alert", msg);
 }

 void MakeNewImage()
 {

  vericode = new Random().Next(100000, 999999).ToString();

  using SkiaSharp.SKBitmap bmp = new SkiaSharp.SKBitmap(200, 80);

  using (SkiaSharp.SKCanvas canvas = new SkiaSharp.SKCanvas(bmp))
  {
   canvas.Clear(SkiaSharp.SKColors.White);
   using SkiaSharp.SKPaint skp = new SkiaSharp.SKPaint();
   skp.Color = SkiaSharp.SKColors.Red;
   skp.TextSize = 40;
   canvas.DrawText(vericode, 30, 55, skp);
   canvas.Save();
  }

  using System.IO.MemoryStream ms = new System.IO.MemoryStream();
  using SkiaSharp.SKManagedWStream ws = new SkiaSharp.SKManagedWStream(ms);
  bmp.Encode(ws, SkiaSharp.SKEncodedImageFormat.Jpeg, 100);

  imgurl = "data:image/jpeg;base64," + Convert.ToBase64String(ms.ToArray());
 }

}