.NET使用ZXing.NET生成中间带图片的二维码

浏览数：87 / 时间：2015年06月09日

很久之前就有写这样的代码了，只是一直没记录下来，偶然想写成博客。

把之前的代码封装成函数，以方便理解以及调用。

基于开源的 ZXing.NET 组件，代码如下：

先添加对ZXing.NET的引用，然后添加相应的命名空间：

using System;
using System.Collections.Generic;
using System.Drawing;
using ZXing;
using ZXing.Common;
using ZXing.QrCode;
using ZXing.QrCode.Internal;

方法一是生成二维码图片：

/// <summary>
/// 生成二维码图片
/// </summary>
/// <param name="contents">要生成二维码包含的信息</param>
/// <param name="width">生成的二维码宽度（默认300像素）</param>
/// <param name="height">生成的二维码高度（默认300像素）</param>
/// <returns>二维码图片</returns>
public static Bitmap GeneratorQrImage(string contents, int width = 300, int height = 300)
{
    if (string.IsNullOrEmpty(contents))
    {
        return null;
    }
    //本文地址：http://www.cnblogs.com/Interkey/p/qrcode.html
    EncodingOptions options = null;
    BarcodeWriter writer = null;
    options = new QrCodeEncodingOptions
    {
        DisableECI = true,
        CharacterSet = "UTF-8",
        Width = width,
        Height = height,
        ErrorCorrection = ErrorCorrectionLevel.H,
    };
    writer = new BarcodeWriter();
    writer.Format = BarcodeFormat.QR_CODE;
    writer.Options = options;

    Bitmap bitmap = writer.Write(contents);
    return bitmap;
}

方法二是生成中间带图片的二维码图片：

/// <summary>
/// 生成中间带有图片的二维码图片
/// </summary>
/// <param name="contents">要生成二维码包含的信息</param>
/// <param name="middleImg">要生成到二维码中间的图片</param>
/// <param name="width">生成的二维码宽度（默认300像素）</param>
/// <param name="height">生成的二维码高度（默认300像素）</param>
/// <returns>中间带有图片的二维码</returns>
public static Bitmap GeneratorQrImage(string contents, Image middleImg, int width = 300, int height = 300)
{
    if (string.IsNullOrEmpty(contents))
    {
        return null;
    }
    if (middleImg == null)
    {
        //return null;
        return GeneratorQrImage(contents);
    }
    ////本文地址：http://www.cnblogs.com/Interkey/p/qrcode.html
    //构造二维码写码器
    MultiFormatWriter mutiWriter = new MultiFormatWriter();
    Dictionary<EncodeHintType, object> hint = new Dictionary<EncodeHintType, object>();
    hint.Add(EncodeHintType.CHARACTER_SET, "UTF-8");
    hint.Add(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);

    //生成二维码
    BitMatrix bm = mutiWriter.encode(contents, BarcodeFormat.QR_CODE, width, height, hint);
    BarcodeWriter barcodeWriter = new BarcodeWriter();
    Bitmap bitmap = barcodeWriter.Write(bm);
            
    //获取二维码实际尺寸（去掉二维码两边空白后的实际尺寸）
    int[] rectangle = bm.getEnclosingRectangle();

    //计算插入图片的大小和位置
    int middleImgW = Math.Min((int)(rectangle[2] / 3.5), middleImg.Width);
    int middleImgH = Math.Min((int)(rectangle[3] / 3.5), middleImg.Height);
    int middleImgL = (bitmap.Width - middleImgW) / 2;
    int middleImgT = (bitmap.Height - middleImgH) / 2;

    //将img转换成bmp格式，否则后面无法创建 Graphics对象
    Bitmap bmpimg = new Bitmap(bitmap.Width, bitmap.Height, System.Drawing.Imaging.PixelFormat.Format32bppArgb);
    using (Graphics g = Graphics.FromImage(bmpimg))
    {
        g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.HighQualityBicubic;
        g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;
        g.CompositingQuality = System.Drawing.Drawing2D.CompositingQuality.HighQuality;
        g.DrawImage(bitmap, 0, 0);
    }

    //在二维码中插入图片
    Graphics myGraphic = Graphics.FromImage(bmpimg);
    //白底
    myGraphic.FillRectangle(Brushes.White, middleImgL, middleImgT, middleImgW, middleImgH);
    myGraphic.DrawImage(middleImg, middleImgL, middleImgT, middleImgW, middleImgH);
    return bmpimg;
}

效果如下：

中间有图片与没有图片的生成的不一样，原因不清楚，初步以为中间有图片的是因为容错率的原故。

对应的解析代码也很简单：

// create a barcode reader instance
IBarcodeReader reader = new BarcodeReader();
// load a bitmap
Bitmap barcodeBitmap = (Bitmap)Image.FromFile("C:\\sample-barcode-image.png");
// detect and decode the barcode inside the bitmap
Result result = reader.Decode(barcodeBitmap);
// do something with the result
if (result != null)
{
    this.txtDecoderType.Text = result.BarcodeFormat.ToString();
    this.txtDecoderContent.Text = result.Text;
}