如何将图像转换为 Base64？

如何将图像转换为 Base64？

可以通过创建字节数组，然后将其转换为 Base64 编码来实现：

public Byte[] GenerateBarcodeStream2D(String data)
{
  TECIT.TBarCode.Barcode barcode = new TECIT.TBarCode.Barcode();
  barcode.BarcodeType = TECIT.TBarCode.BarcodeType.DataMatrix;
  barcode.Data = data;
  barcode.Dpi = 100;
  Size optimalSize = barcode.CalculateOptimalBitmapSize(null, 2, 2);
  barcode.BoundingRectangle = new Rectangle(0, 0, optimalSize.Width, optimalSize.Height);
  using (System.IO.MemoryStream ms = new System.IO.MemoryStream())
  {
    Bitmap bitmap = barcode.DrawBitmap();
    bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);
    /*
     * // or save as 24 bit JPG
     *  ImageCodecInfo jpgCodec = ImageCodecInfo.GetImageEncoders().Where(codec => codec.FormatID.Equals(ImageFormat.Jpeg.Guid)).FirstOrDefault();
     *  System.Drawing.Imaging.EncoderParameters parameters = new System.Drawing.Imaging.EncoderParameters();
     *  parameters.Param[0] = new EncoderParameter (System.Drawing.Imaging.Encoder.ColorDepth, 24);
     *  bitmap.Save(ms, jpgCodec, parameters);
    */
    ms.Position = 0;
    return ms.ToArray();
  }
}

创建字节数组之后，您可以将该数组转换为 Base64。要将图像嵌入 html 中，请在图像前加上 MIME 类型前缀：

Byte[] barcodeImageStream = GenerateBarcodeStream2D ("12345");
String myBase64Barcode = Convert.ToBase64String(barcodeImageStream);
String imgSrc = "data:image/png;base64, " + myBase64Barcode;