using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using QRCoder;
using Windows.Devices.PointOfService;
using ZXing;
using ZXing.Common;
using ZXing.QrCode;
using ZXing.QrCode.Internal;

namespace WinFormsApp4
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            string name = "1234";
            QRCodeGenerator QR = new QRCodeGenerator();
            QRCodeData cd = QR.CreateQrCode(name, QRCodeGenerator.ECCLevel.Q);
           QRCoder.QRCode qRCode = new QRCoder.QRCode(cd);

            Bitmap qrCodeImage = qRCode.GetGraphic(5, Color.Black, Color.White, null, 15, 6, false);

            qrCodeImage.Save(Environment.CurrentDirectory + "\\t.jpeg");
        }

        private void button2_Click(object sender, EventArgs e)
        {


            button2.Text = DecodeQrCode(Environment.CurrentDirectory + "\\t.jpeg");
        }


        string DecodeQrCode(string filename)
        {
            //直接new Bitmap会导致图片占用，无法再次覆盖生成
            Bitmap bitmap = FileToBitmap(filename);
            try
            {
                BarcodeReader reader = new BarcodeReader { AutoRotate = true };
                Result result = reader.Decode(bitmap);
                string decodedData = result.Text;

                return decodedData;
            }
            catch
            {
                throw new Exception("Cannot decode the QR code");
            }
            return null;
        }

        /// <summary>
        /// 读取Bitmap图片，防止资源占用导致在此读取失败
        /// </summary>
        /// <param name="fileName"></param>
        /// <returns></returns>
        Bitmap FileToBitmap(string fileName)
        {
            // 打开文件  
            FileStream fileStream = new FileStream(fileName, FileMode.Open, FileAccess.Read, FileShare.Read);
            // 读取文件的 byte[]  
            byte[] bytes = new byte[fileStream.Length];
            fileStream.Read(bytes, 0, bytes.Length);
            fileStream.Close();
            // 把 byte[] 转换成 Stream  
            Stream stream = new MemoryStream(bytes);

            stream.Read(bytes, 0, bytes.Length);
            // 设置当前流的位置为流的开始  
            stream.Seek(0, SeekOrigin.Begin);

            MemoryStream mstream = null;
            try
            {
                mstream = new MemoryStream(bytes);
                return new Bitmap((Image)new Bitmap(stream));
            }
            catch (ArgumentNullException ex)
            {
                return null;
            }
            catch (ArgumentException ex)
            {
                return null;
            }
            finally
            {
                stream.Close();
            }
        }

    }
}

---

Filed under: C#,编程 - @ 2021年9月7日 下午10:06