asp.net - 如何在 mvc 6 .net core 5 中使用图像验证码？

Question

我想知道如何在 mvc 6 .net core 5 GDi+ 中使用图像绘制？引用 systeam.drawing 库未在 .net core 5 中使用我想通过 .net core 5 使用此代码

private static Bitmap GenerateRandomCaptchaImage(string text)
{
    var bitmap = new Bitmap(200, 150);
    var g = Graphics.FromImage(bitmap);

    var pen = new Pen(Color.Yellow);
    var rect = new System.Drawing.Rectangle(0, 0, 200, 150);
    var brush = new SolidBrush(Color.Blue);

   g.DrawRectangle(pen, rect);
   g.FillRectangle(brush, rect);           
   g.DrawString(text, new Font("Georgia", 20), new SolidBrush(Color.Black), 10, 50);

   DrawRandomLines(g);

    g.Dispose();
    return bitmap;
}

private static System.Drawing.Point[] GetRandomPoints()
{
    var rand = new Random();

    System.Drawing.Point[] points = { new System.Drawing.Point(rand.Next(10, 150), rand.Next(10, 150)), new System.Drawing.Point(rand.Next(10, 100), rand.Next(10, 100)) };

    return points;
}

private static void DrawRandomLines(Graphics g)
{
    SolidBrush green = new SolidBrush(Color.Green);

    for (int i = 0; i < 20; i++)
    {
        g.DrawLines(new Pen(green, 2), GetRandomPoints());
    }
}

Answer 1

(目前？)解决方案中不完全支持在 .net Core 中使用 system.drawing。
相反，请尝试使用 Mono 的开源 System.Drawing 实现。

哪个是 System.Drawing 替代品？ https://github.com/dotnet/corefx/issues/3634

进一步阅读: https://github.com/dotnet/corefx/issues/5921