QRCoder1.4.3生成二维码，不依赖System.Drawing，解决"未能找到类型或命名空间名QRCode"，"及ImageFormatPng仅在windows上受支持"

/// <summary>
/// 生成二维码
/// </summary>
/// <param name="data">escape后的数据，防止中文等特殊字符引起问题</param>
/// <param name="size">二维码宽高</param>
/// <param name="level">0.L (7%), 1.M (15%), 2.Q (25%) 3.H (30%)</param>
/// <param name="border">是否包含白边</param>
/// <returns></returns>
[HttpGet]
public IActionResult Generate(string text, int size = 400, int level = 1, bool border = false)
{
    if (string.IsNullOrEmpty(text))
        return BadRequest("内容不能为空.");

    //设置最小和最大尺寸50-1920
    size = size < 50 ? 50 : size > 1920 ? 1920 : size;

    QRCodeGenerator qrGenerator = new();
    QRCodeData qrCodeData = qrGenerator.CreateQrCode(text, (QRCodeGenerator.ECCLevel)level);

    int pixelsPerModule = size / 21; //size = pixelsPerModule * 21
    using PngByteQRCode qrCode = new(qrCodeData);
    byte[] qrCodeBytes = qrCode.GetGraphic(pixelsPerModule, drawQuietZones: border);

    // 将字节数组转换为Base64字符串
    string base64Image = Convert.ToBase64String(qrCodeBytes);
    // 返回Base64字符串作为图片的src属性值 // return $"data:image/png;base64,{base64Image}";
    return File(qrCodeBytes, "image/png", "QrCode.png");
}

 [HttpGet]
 public IActionResult Generate2(string text, int size = 400, int level = 1, int borderWidth = 0)
 {
     if (string.IsNullOrEmpty(text))
         return BadRequest("内容不能为空.");

     //设置最小和最大尺寸50-1920
     size = size < 50 ? 50 : size > 1920 ? 1920 : size;

     QRCodeGenerator qrGenerator = new();
     QRCodeData qrCodeData = qrGenerator.CreateQrCode(text, (QRCodeGenerator.ECCLevel)level);

     using PngByteQRCode qrCode = new(qrCodeData);
     byte[] qrCodeBytes = qrCode.GetGraphic(50, drawQuietZones: false);

     using MemoryStream stream = new(qrCodeBytes);
     using Image<Rgba32> qrCodeImage = Image.Load<Rgba32>(stream);

     // 调整图像大小
     qrCodeImage.Mutate(ctx => ctx.Resize(size, size));

     // 添加空白来模拟白边
     borderWidth = borderWidth <= 0 ? 50 : borderWidth; // 调整白边的宽度
     Image<Rgba32> borderedImage = new(qrCodeImage.Width + 2 * borderWidth, qrCodeImage.Height + 2 * borderWidth);
     borderedImage.Mutate(ctx => ctx.BackgroundColor(Color.White).DrawImage(qrCodeImage, new Point(borderWidth, borderWidth), 1f));

     // 将调整大小后的图像保存为字节数组
     using MemoryStream resizedStream = new();
     borderedImage.Save(resizedStream, new PngEncoder());
     byte[] resizedBytes = resizedStream.ToArray();

     // 将字节数组转换为Base64字符串
     string base64Image = Convert.ToBase64String(resizedBytes);
     // 返回Base64字符串作为图片的src属性值 // return $"data:image/png;base64,{base64Image}";
     return File(resizedBytes, "image/png", "QrCode.png");
 }