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
 {
     partial class Form1
     {
         /// <summary>
         /// 必需的设计器变量。
         /// </summary>
         private System.ComponentModel.IContainer components = null;
 
         /// <summary>
         /// 清理所有正在使用的资源。
         /// </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)
         {
             if (disposing && (components != null))
             {
                 components.Dispose();
             }
             base.Dispose(disposing);
         }
 
         #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
         /// 使用代码编辑器修改此方法的内容。
         /// </summary>
         private void InitializeComponent()
         {
             this.button1 = new System.Windows.Forms.Button();
             this.button2 = new System.Windows.Forms.Button();
             this.pictureBox1 = new System.Windows.Forms.PictureBox();
             this.label1 = new System.Windows.Forms.Label();
             this.textBox1 = new System.Windows.Forms.TextBox();
             this.label2 = new System.Windows.Forms.Label();
             this.lbl解码信息 = new System.Windows.Forms.Label();
             ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).BeginInit();
             this.SuspendLayout();
             //
             // button1
             //
             this.button1.Location = new System.Drawing.Point(, );
             this.button1.Margin = new System.Windows.Forms.Padding(, , , );
             this.button1.Name = "button1";
             this.button1.Size = new System.Drawing.Size(, );
             this.button1.TabIndex = ;
             this.button1.Text = "编码";
             this.button1.UseVisualStyleBackColor = true;
             this.button1.Click += new System.EventHandler(this.button1_Click);
             //
             // button2
             //
             this.button2.Location = new System.Drawing.Point(, );
             this.button2.Margin = new System.Windows.Forms.Padding(, , , );
             this.button2.Name = "button2";
             this.button2.Size = new System.Drawing.Size(, );
             this.button2.TabIndex = ;
             this.button2.Text = "解码";
             this.button2.UseVisualStyleBackColor = true;
             this.button2.Click += new System.EventHandler(this.button2_Click);
             //
             // pictureBox1
             //
             this.pictureBox1.Location = new System.Drawing.Point(, );
             this.pictureBox1.Margin = new System.Windows.Forms.Padding(, , , );
             this.pictureBox1.Name = "pictureBox1";
             this.pictureBox1.Size = new System.Drawing.Size(, );
             this.pictureBox1.SizeMode = System.Windows.Forms.PictureBoxSizeMode.StretchImage;
             this.pictureBox1.TabIndex = ;
             this.pictureBox1.TabStop = false;
             //
             // label1
             //
             this.label1.AutoSize = true;
             this.label1.Location = new System.Drawing.Point(, );
             this.label1.Margin = new System.Windows.Forms.Padding(, , , );
             this.label1.Name = "label1";
             this.label1.Size = new System.Drawing.Size(, );
             this.label1.TabIndex = ;
             this.label1.Text = "信息：";
             //
             // textBox1
             //
             this.textBox1.Location = new System.Drawing.Point(, );
             this.textBox1.Margin = new System.Windows.Forms.Padding(, , , );
             this.textBox1.Name = "textBox1";
             this.textBox1.Size = new System.Drawing.Size(, );
             this.textBox1.TabIndex = ;
             //
             // label2
             //
             this.label2.AutoSize = true;
             this.label2.Location = new System.Drawing.Point(, );
             this.label2.Margin = new System.Windows.Forms.Padding(, , , );
             this.label2.Name = "label2";
             this.label2.Size = new System.Drawing.Size(, );
             this.label2.TabIndex = ;
             this.label2.Text = "二维码：";
             //
             // lbl解码信息
             //
             this.lbl解码信息.AutoSize = true;
             this.lbl解码信息.Location = new System.Drawing.Point(, );
             this.lbl解码信息.Margin = new System.Windows.Forms.Padding(, , , );
             this.lbl解码信息.Name = "lbl解码信息";
             this.lbl解码信息.Size = new System.Drawing.Size(, );
             this.lbl解码信息.TabIndex = ;
             //
             // Form1
             //
             this.AutoScaleDimensions = new System.Drawing.SizeF(11F, 24F);
             this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
             this.ClientSize = new System.Drawing.Size(, );
             this.Controls.Add(this.lbl解码信息);
             this.Controls.Add(this.label2);
             this.Controls.Add(this.textBox1);
             this.Controls.Add(this.label1);
             this.Controls.Add(this.pictureBox1);
             this.Controls.Add(this.button2);
             this.Controls.Add(this.button1);
             this.Font = new System.Drawing.Font("微软雅黑", 10.8F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)()));
             this.Margin = new System.Windows.Forms.Padding(, , , );
             this.Name = "Form1";
             this.Text = "二维码";
             ((System.ComponentModel.ISupportInitialize)(this.pictureBox1)).EndInit();
             this.ResumeLayout(false);
             this.PerformLayout();
 
         }
 
         #endregion
 
         private System.Windows.Forms.Button button1;
         private System.Windows.Forms.Button button2;
         private System.Windows.Forms.PictureBox pictureBox1;
         private System.Windows.Forms.Label label1;
         private System.Windows.Forms.TextBox textBox1;
         private System.Windows.Forms.Label label2;
         private System.Windows.Forms.Label lbl解码信息;
     }
 }

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;
 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Data;
 using System.Drawing;
 using System.Linq;
 using System.Text;
 using System.Windows.Forms;
 
 namespace WinQRCode
 {
     using ThoughtWorks.QRCode.Codec;
     using ThoughtWorks.QRCode.Codec.Data;
     using ThoughtWorks.QRCode.Codec.Util;
     using System.IO;
     using PdfToImage;
     public partial class Form1 : Form
     {
         public Form1()
         {
             InitializeComponent();
         }
         /// <summary>
         /// 编码
         /// </summary>
         /// <param name="sender"></param>
         /// <param name="e"></param>
         private void button1_Click(object sender, EventArgs e)
         {
             if (this.textBox1.Text != "")
             {
                 Cursor.Current = Cursors.WaitCursor;
                 if (textBox1.Text.Trim() == String.Empty)
                 {
                     MessageBox.Show("不能为空.");
                     return;
                 }
                 QRCodeEncoder qrCodeEncoder = new QRCodeEncoder();
                 qrCodeEncoder.QRCodeEncodeMode = QRCodeEncoder.ENCODE_MODE.BYTE;
                 qrCodeEncoder.QRCodeScale = ;
                 qrCodeEncoder.QRCodeVersion = ;
                qrCodeEncoder.QRCodeErrorCorrect = QRCodeEncoder.ERROR_CORRECTION.M;
                 System.Drawing.Image image;
                 String data = textBox1.Text;
                 //编码
                 image = qrCodeEncoder.Encode(data);
                 //图片显示
                 this.pictureBox1.Image = image;
                 Cursor.Current = Cursors.Default;
 
             }
         }
         /// <summary>
         /// 解码
         /// </summary>
         /// <param name="sender"></param>
         /// <param name="e"></param>
         private void button2_Click(object sender, EventArgs e)
         {
             Cursor.Current = Cursors.WaitCursor;
             Bitmap b = this.pictureBox1.Image as Bitmap;
             try
             {
                 QRCodeDecoder decoder = new QRCodeDecoder();
                 //解码
                 String decodedString = decoder.decode(new QRCodeBitmapImage(b));
                 //显示解码信息
                 this.lbl解码信息.Text += decodedString ;
             }
             catch (Exception ex)
             {
                 MessageBox.Show(ex.Message);
             }
             Cursor.Current = Cursors.Default;
         }
 
         private void Form1_Load(object sender, EventArgs e)
         {
 
         }
     }
 }

4、编译运行，如下图：