如何用.NET生成二维码？

　　二维码是用某种特定的几何图形按一定规律在平面（二维方向上）分布的黑白相间的图形记录数据符号信息的，国外对二维码技术的研究始于20世纪80年代末，在二维码符号表示技术研究方面已研制出多种码制，常见的有PDF417、QR Code、Code 49、Code 16K、Code One等。二维码技术已经被广泛应用于公安、外交、军事等部门对各类证件的管理，而且也将二维码应用于海关、税务等部门对各类报表和票据的管理，商业、交通运输等部门对商品及货物运输的管理、邮政部门对邮政包裹的管理、工业生产领域对工业生产线的自动化管理。

　　下面介绍一下如何用.NET生成二维码（QR Code码制），下面给出详细步骤：

1、新建一个window应用程序，然后引入.NET二维码类库（开源的类库，可从网上下载）：

2、构建UI界面，代码如下：

namespace WinQRCode  2 {  3     partial class Form1  4  {  5         /// <summary>
        /// 必需的设计器变量。  7         /// </summary>
        private System.ComponentModel.IContainer components = null;  9 
        /// <summary>
        /// 清理所有正在使用的资源。  12         /// </summary>
        /// <param name="disposing">如果应释放托管资源，为 true；否则为 false。</param>
        protected override void Dispose(bool disposing)  15  {  16             if (disposing && (components != null))  17  {  18  components.Dispose();  19  }  20             base.Dispose(disposing);  21  }  22 
        #region Windows 窗体设计器生成的代码

        /// <summary>
        /// 设计器支持所需的方法 - 不要  27         /// 使用代码编辑器修改此方法的内容。  28         /// </summary>
        private void InitializeComponent()  30  {  31             this.button1 = new System.Windows.Forms.Button();  32             this.button2 = new System.Windows.Forms.Button();  33             this.pictureBox1 = new System.Windows.Forms.PictureBox();  34             this.label1 = new System.Windows.Forms.Label();  35             this.textBox1 = new System.Windows.Forms.TextBox();  36             this.label2 = new System.Windows.Forms.Label();  37             this.lbl解码信息 = new System.Windows.Forms.Label();  38             ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).BeginInit();  39             this.SuspendLayout();  40             // 
            // button1  42             // 
            this.button1.Location = new System.Drawing.Point(446, 31);  44             this.button1.Margin = new System.Windows.Forms.Padding(4, 5, 4, 5);  45             this.button1.Name = "button1";  46             this.button1.Size = new System.Drawing.Size(103, 37);  47             this.button1.TabIndex = 0;  48             this.button1.Text = "编码";  49             this.button1.UseVisualStyleBackColor = true;  50             this.button1.Click += new System.EventHandler(this.button1_Click);  51             // 
            // button2  53             // 
            this.button2.Location = new System.Drawing.Point(446, 81);  55             this.button2.Margin = new System.Windows.Forms.Padding(4, 5, 4, 5);  56             this.button2.Name = "button2";  57             this.button2.Size = new System.Drawing.Size(103, 37);  58             this.button2.TabIndex = 1;  59             this.button2.Text = "解码";  60             this.button2.UseVisualStyleBackColor = true;  61             this.button2.Click += new System.EventHandler(this.button2_Click);  62             // 
            // pictureBox1  64             // 
            this.pictureBox1.Location = new System.Drawing.Point(23, 117);  66             this.pictureBox1.Margin = new System.Windows.Forms.Padding(4, 5, 4, 5);  67             this.pictureBox1.Name = "pictureBox1";  68             this.pictureBox1.Size = new System.Drawing.Size(279, 253);  69             this.pictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.StretchImage;  70             this.pictureBox1.TabIndex = 2;  71             this.pictureBox1.TabStop = false;  72             // 
            // label1  74             // 
            this.label1.AutoSize = true;  76             this.label1.Location = new System.Drawing.Point(18, 39);  77             this.label1.Margin = new System.Windows.Forms.Padding(4, 0, 4, 0);  78             this.label1.Name = "label1";  79             this.label1.Size = new System.Drawing.Size(69, 25);  80             this.label1.TabIndex = 3;  81             this.label1.Text = "信息：";  82             // 
            // textBox1  84             // 
            this.textBox1.Location = new System.Drawing.Point(95, 37);  86             this.textBox1.Margin = new System.Windows.Forms.Padding(4, 5, 4, 5);  87             this.textBox1.Name = "textBox1";  88             this.textBox1.Size = new System.Drawing.Size(333, 31);  89             this.textBox1.TabIndex = 4;  90             // 
            // label2  92             // 
            this.label2.AutoSize = true;  94             this.label2.Location = new System.Drawing.Point(18, 81);  95             this.label2.Margin = new System.Windows.Forms.Padding(4, 0, 4, 0);  96             this.label2.Name = "label2";  97             this.label2.Size = new System.Drawing.Size(88, 25);  98             this.label2.TabIndex = 5;  99             this.label2.Text = "二维码："; 100             // 
            // lbl解码信息 102             // 
            this.lbl解码信息.AutoSize = true; 104             this.lbl解码信息.Location = new System.Drawing.Point(101, 81); 105             this.lbl解码信息.Margin = new System.Windows.Forms.Padding(4, 0, 4, 0); 106             this.lbl解码信息.Name = "lbl解码信息"; 107             this.lbl解码信息.Size = new System.Drawing.Size(0, 25); 108             this.lbl解码信息.TabIndex = 6; 109             // 
            // Form1 111             // 
            this.AutoScaleDimensions = new System.Drawing.SizeF(11F, 24F); 113             this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font; 114             this.ClientSize = new System.Drawing.Size(572, 384); 115             this.Controls.Add(this.lbl解码信息); 116             this.Controls.Add(this.label2); 117             this.Controls.Add(this.textBox1); 118             this.Controls.Add(this.label1); 119             this.Controls.Add(this.pictureBox1); 120             this.Controls.Add(this.button2); 121             this.Controls.Add(this.button1); 122             this.Font = new System.Drawing.Font("微软雅黑", 10.8F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(134))); 123             this.Margin = new System.Windows.Forms.Padding(4, 5, 4, 5); 124             this.Name = "Form1"; 125             this.Text = "二维码"; 126             ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).EndInit(); 127             this.ResumeLayout(false); 128             this.PerformLayout(); 129 
 } 131 
        #endregion

        private System.Windows.Forms.Button button1; 135         private System.Windows.Forms.Button button2; 136         private System.Windows.Forms.PictureBox pictureBox1; 137         private System.Windows.Forms.Label label1; 138         private System.Windows.Forms.TextBox textBox1; 139         private System.Windows.Forms.Label label2; 140         private System.Windows.Forms.Label lbl解码信息; 141  } 142 }

图形如下所示：

3、编写 编码和解码按钮事件，进行编码和解码处理：

using System;  2 using System.Collections.Generic;  3 using System.ComponentModel;  4 using System.Data;  5 using System.Drawing;  6 using System.Linq;  7 using System.Text;  8 using System.Windows.Forms;  9 
namespace WinQRCode 11 { 12     using ThoughtWorks.QRCode.Codec; 13     using ThoughtWorks.QRCode.Codec.Data; 14     using ThoughtWorks.QRCode.Codec.Util; 15     using System.IO; 16     using PdfToImage; 17     public partial class Form1 : Form 18  { 19         public Form1() 20  { 21  InitializeComponent(); 22  } 23         /// <summary>
        /// 编码 25         /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button1_Click(object sender, EventArgs e) 29  { 30             if (this.textBox1.Text != "") 31  { 32                 Cursor.Current = Cursors.WaitCursor; 33                 if (textBox1.Text.Trim() == String.Empty) 34  { 35                     MessageBox.Show("不能为空."); 36                     return; 37  } 38                 QRCodeEncoder qrCodeEncoder = new QRCodeEncoder(); 39                 qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.BYTE; 40                 qrCodeEncoder.QRCodeScale = 4; 41                 qrCodeEncoder.QRCodeVersion = 7; 42                qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.M; 43  System.Drawing.Image image; 44                 String data = textBox1.Text; 45                 //编码
                image = qrCodeEncoder.Encode(data); 47                 //图片显示
                this.pictureBox1.Image = image; 49                 Cursor.Current = Cursors.Default; 50 
 } 52  } 53         /// <summary>
        /// 解码 55         /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button2_Click(object sender, EventArgs e) 59  { 60             Cursor.Current = Cursors.WaitCursor; 61             Bitmap b = this.pictureBox1.Image as Bitmap; 62             try
 { 64                 QRCodeDecoder decoder = new QRCodeDecoder(); 65                 //解码
                String decodedString = decoder.decode(new QRCodeBitmapImage(b)); 67                 //显示解码信息
                this.lbl解码信息.Text += decodedString ; 69  } 70             catch (Exception ex) 71  { 72  MessageBox.Show(ex.Message); 73  } 74             Cursor.Current = Cursors.Default; 75  } 76 
        private void Form1_Load(object sender, EventArgs e) 78  { 79 
 } 81  } 82 }

4、编译运行，如下图：