C#中生成二维码（QR码）与读取二维码内容
使用开源类库ZXing.dll可以在C#中生成二维码和解析二维码为指定的字符串（含url）
新建windows窗体应用程序QRCodeDemo，.net 4.5,将默认的Form1重命名为FormQuickResponseCode。
添加对开源类库zxing.dll和zxing.presentation.dll的引用，用于解析和生成条码【一维条码、二维条码均可生成】。
窗体FormQuickResponseCode设计器如下：
新建读写二维码类QrCodeUtil，QrCodeUtil.cs源程序如下：
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using ZXing;
using ZXing.QrCode;
using ZXing.QrCode.Internal;
namespace QRCodeDemo
{
///
/// 文本字符串与二维码图片之间的转换
/// 字符串转二维码 String---->Image
/// 二维码转字符串 Image---->String
///
public class QrCodeUtil
{
///
/// 将文本字符串转化为二维码图片
///
/// 打印条码对应的字符串
///
///
/// 条码格式：CODE_128代表一维条码，QR_CODE代表二维码
///
///
/// 解码二维码,返回一个文本字符串，如果返回为null，则解析(转化)失败
///
/// 待解码的二维码图片
/// 扫码结果
public static string DecodeQrCode(Bitmap barcodeBitmap)
{
BarcodeReader reader = new BarcodeReader();
reader.Options.CharacterSet = "UTF-8";
Result result = reader.Decode(barcodeBitmap);
return (result == null) ? null : result.Text;
}
///
/// 获取纠错级别
///
///
/// 窗体FormQuickResponseCode 主要程序如下（忽略设计器自动生成的代码）：
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace QRCodeDemo
{
public partial class FormQuickResponseCode : Form
{
public FormQuickResponseCode()
{
InitializeComponent();
//矩阵二维码QRCode： Quick Response Code
rtxtCodeMessage.Text = "https://blog.csdn.net/ylq1045\n斯内科";
this.cboImageFormat.Items.AddRange(new object[] {
"GIF",
"JPG/JPEG",
"PNG",
"BMP"});
this.cboErrorCorrectionLevel.Items.AddRange(new object[] {
"L 7%",
"M 15%",
"Q 25%",
"H 30%"});
cboImageFormat.SelectedIndex = 1;
cboErrorCorrectionLevel.SelectedIndex = 1;
}
private void btnGenerateQR_Click(object sender, EventArgs e)
{
if (rtxtCodeMessage.Text.Length == 0)
{
MessageBox.Show("请输入URL或者文本字符串", "提示");
return;
}
string errorCorrectionLevel = "M";
if (cboErrorCorrectionLevel.Text.Length > 0)
{
errorCorrectionLevel = cboErrorCorrectionLevel.Text.Substring(0, 1);
}
Bitmap bitmap = QrCodeUtil.GeneateQrCode(rtxtCodeMessage.Text, 200, 200, ZXing.BarcodeFormat.QR_CODE,errorCorrectionLevel);
pictureBox1.SizeMode = PictureBoxSizeMode.CenterImage;
pictureBox1.Image = bitmap;
}
private void btnExport_Click(object sender, EventArgs e)
{
SaveFileDialog saveImageDialog = new SaveFileDialog();
saveImageDialog.Title = "图片保存";
switch (cboImageFormat.Text)
{
case "GIF":
saveImageDialog.Filter = "gif|*.gif|All|*.*";
break;
case "JPG/JPEG":
saveImageDialog.Filter = "jpeg|*.jpg|All|*.*";
break;
case "PNG":
saveImageDialog.Filter = "png|*.png|All|*.*";
break;
case "BMP":
saveImageDialog.Filter = "bmp|*.bmp|All|*.*";
break;
default:
saveImageDialog.Filter = "jpeg|*.jpg|bmp|*.bmp|gif|*.gif|png|*.png|All|*.*";
break;
}
if (saveImageDialog.ShowDialog() == DialogResult.OK)
{
System.Drawing.Imaging.ImageFormat imgformat = GetImageFormat(cboImageFormat.Text);
string fileName = saveImageDialog.FileName;
try
{
pictureBox1.Image.Save(fileName, imgformat);
MessageBox.Show($"导出成功，图片文件路径：\n{fileName}", "导出文件");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "导出文件出错");
}
}
}
private void btnOpenFile_Click(object sender, EventArgs e)
{
OpenFileDialog openFileDialog = new OpenFileDialog();
openFileDialog.Filter= "jpeg|*.jpg|bmp|*.bmp|gif|*.gif|png|*.png|All|*.*";
if (openFileDialog.ShowDialog() == DialogResult.OK)
{
string fileName = openFileDialog.FileName;
try
{
pictureBox1.SizeMode = PictureBoxSizeMode.CenterImage;
pictureBox1.Image = Image.FromFile(fileName);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "打开图像文件出错");
}
}
}
private void btnDiscern_Click(object sender, EventArgs e)
{
rtxtCodeMessage.Clear();
try
{
string codeMessage = QrCodeUtil.DecodeQrCode(new Bitmap(pictureBox1.Image));
if (string.IsNullOrEmpty(codeMessage))
{
MessageBox.Show($"识别二维码图片出错,可能不是二维码图片格式，或者过于模糊，\n请打开新的二维码图片重新尝试", "识别二维码图片出错");
return;
}
rtxtCodeMessage.Text = codeMessage;
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "识别二维码图片出错");
}
}
///
/// 获取图像文件格式
///
///
/// 测试运行如图：
