C# 代码生成二维码方法及代码示例（QRCoder）

Posted 2021-04-14 老王Plus

二维码是越来越流行了，很多地方都有可能是使用到。如果是静态的二维码还是比较好处理的，通过在线工具就可以直接生成一张二维码图片，比如：草料二维码。但有的时候是需要动态生成的（根据动态数据生成），这个使用在线就工具就无法实现了。最好是能在代码中直接生成一个二维码图片，这里我就介绍下使用QRCoder类库在代码中生成二维码。

网上生成二维码的组件还是挺多的，但是真正好用且快速的却不多。QRCoder就是我在众多中找到的，它的生成速度快、而且使用也相当方便。

开始编码

1、安装 QRCoder组件。在项目上通过NuGet包管理器来安装，搜索名称：QRCoder

2、在代码中添加引用：using QRCoder;

3、编码生成

 private void RenderQrCode() { string level = comboBoxECC.SelectedItem.ToString(); QRCodeGenerator.ECCLevel eccLevel = (QRCodeGenerator.ECCLevel)(level == "L" ? 0 : level == "M" ? 1 : level == "Q" ? 2 : 3); using (QRCodeGenerator qrGenerator = new QRCodeGenerator()) { using (QRCodeData qrCodeData = qrGenerator.CreateQrCode(textBoxQRCode.Text, eccLevel)) { using (QRCode qrCode = new QRCode(qrCodeData)) {
 pictureBoxQRCode.BackgroundImage = qrCode.GetGraphic(20, Color.Black, Color.White, GetIconBitmap(), (int) iconSize.Value);
 this.pictureBoxQRCode.Size = new System.Drawing.Size(pictureBoxQRCode.Width, pictureBoxQRCode.Height); //Set the SizeMode to center the image. this.pictureBoxQRCode.SizeMode = PictureBoxSizeMode.CenterImage;
 pictureBoxQRCode.SizeMode = PictureBoxSizeMode.StretchImage; } } } }

上面代码运行的结果

还可以加上logo

 private Bitmap GetIconBitmap() { Bitmap img = null; if (iconPath.Text.Length > 0) { try { img = new Bitmap(iconPath.Text); } catch (Exception) { } } return img; }

完整代码

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using QRCoder;using System.Drawing.Imaging;using System.IO;
namespace QRCoderDemo{ public partial class Form1 : Form { public Form1() { InitializeComponent(); }
 private void Form1_Load(object sender, EventArgs e) { comboBoxECC.SelectedIndex = 0; //Pre-select ECC level "L" RenderQrCode(); }
 private void buttonGenerate_Click(object sender, EventArgs e) { RenderQrCode(); }
 private void RenderQrCode() { string level = comboBoxECC.SelectedItem.ToString(); QRCodeGenerator.ECCLevel eccLevel = (QRCodeGenerator.ECCLevel)(level == "L" ? 0 : level == "M" ? 1 : level == "Q" ? 2 : 3); using (QRCodeGenerator qrGenerator = new QRCodeGenerator()) { using (QRCodeData qrCodeData = qrGenerator.CreateQrCode(textBoxQRCode.Text, eccLevel)) { using (QRCode qrCode = new QRCode(qrCodeData)) {
 pictureBoxQRCode.BackgroundImage = qrCode.GetGraphic(20, Color.Black, Color.White, GetIconBitmap(), (int) iconSize.Value);
 this.pictureBoxQRCode.Size = new System.Drawing.Size(pictureBoxQRCode.Width, pictureBoxQRCode.Height); //Set the SizeMode to center the image. this.pictureBoxQRCode.SizeMode = PictureBoxSizeMode.CenterImage;
 pictureBoxQRCode.SizeMode = PictureBoxSizeMode.StretchImage; } } } }
 private Bitmap GetIconBitmap() { Bitmap img = null; if (iconPath.Text.Length > 0) { try { img = new Bitmap(iconPath.Text); } catch (Exception) { } } return img; }
 private void selectIconBtn_Click(object sender, EventArgs e) { OpenFileDialog openFileDlg = new OpenFileDialog(); openFileDlg.Title = "Select icon"; openFileDlg.Multiselect = false; openFileDlg.CheckFileExists = true; if (openFileDlg.ShowDialog() == System.Windows.Forms.DialogResult.OK) { iconPath.Text = openFileDlg.FileName; if (iconSize.Value == 0) { iconSize.Value = 15; } } else { iconPath.Text = ""; } }

 private void btn_save_Click(object sender, EventArgs e) {
 // Displays a SaveFileDialog so the user can save the Image SaveFileDialog saveFileDialog1 = new SaveFileDialog(); saveFileDialog1.Filter = "Bitmap Image|*.bmp|PNG Image|*.png|JPeg Image|*.jpg|Gif Image|*.gif"; saveFileDialog1.Title = "Save an Image File"; saveFileDialog1.ShowDialog();
 // If the file name is not an empty string open it for saving. if (saveFileDialog1.FileName != "") { // Saves the Image via a FileStream created by the OpenFile method. using (FileStream fs = (System.IO.FileStream) saveFileDialog1.OpenFile()) { // Saves the Image in the appropriate ImageFormat based upon the // File type selected in the dialog box. // NOTE that the FilterIndex property is one-based.
 ImageFormat imageFormat = null; switch (saveFileDialog1.FilterIndex) { case 1: imageFormat = ImageFormat.Bmp; break; case 2: imageFormat = ImageFormat.Png; break; case 3: imageFormat = ImageFormat.Jpeg; break; case 4: imageFormat = ImageFormat.Gif; break; default: throw new NotSupportedException("File extension is not supported"); }
 pictureBoxQRCode.BackgroundImage.Save(fs, imageFormat); fs.Close(); } }




 }
 public void ExportToBmp(string path) {
 }
 private void textBoxQRCode_TextChanged(object sender, EventArgs e) { RenderQrCode(); }
 private void comboBoxECC_SelectedIndexChanged(object sender, EventArgs e) { RenderQrCode(); } }}

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