QR code 和 Barcode 经常会使用到。

Java 阵营有著名的 zxing

.Net 有对接它的 port

调用很简单

var qrWriter = new BarcodeWriterPixelData{    Format = BarcodeFormat.QR_CODE,    Options = new EncodingOptions { Height = 1000, Width = 1000, Margin = 10 }};var pixelData = qrWriter.Write("i love you");using (var bitmap = new Bitmap(pixelData.Width, pixelData.Height, System.Drawing.Imaging.PixelFormat.Format32bppRgb))using (var ms = new MemoryStream()){    // lock the data area for fast access    var bitmapData = bitmap.LockBits(new Rectangle(0, 0, pixelData.Width, pixelData.Height),        System.Drawing.Imaging.ImageLockMode.WriteOnly, System.Drawing.Imaging.PixelFormat.Format32bppRgb);    try    {        // we assume that the row stride of the bitmap is aligned to 4 byte multiplied by the width of the image        System.Runtime.InteropServices.Marshal.Copy(pixelData.Pixels, 0, bitmapData.Scan0,            pixelData.Pixels.Length);    }    finally    {        bitmap.UnlockBits(bitmapData);    }    // save to stream as PNG    //bitmap.Save(ms, System.Drawing.Imaging.ImageFormat.Png);    bitmap.Save(@"C:\keatkeat\my projects\asp.net core\2.2\html-to-pdf\Project\123.png", System.Drawing.Imaging.ImageFormat.Png);}

Barcode Format 有很多种，可以自己选。

这里用到了 bitmap, 是从官网的 demo 里抄来的. 

早期 core 不支持 system draw, 所以 demo 里说依赖 CoreCompat.System.Drawing, 

但后来 .net core 推出了 System.Drawing.Common 所以是跨平台的了.

demo :