C# 代码生成二维码方法及代码示例（QRCoder）-技术圈

背景

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;                    }                }            }        }

运行效果

上面代码运行的结果

加个Logo吧

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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