本文主要介绍如何在.net环境下,基于Asp.Net Core,利用ZXing来生成二维码的一般操作。对二维码工作原理了解,详情见:https://blog.csdn.net/weixin_36191602/article/details/82466148文章介绍。
1、前期准备
.net core preview8,vs2019(用于支持core3.0),二维码生成插件:开源库ZXIng。相关插件可以在github上找到。安装vs2019后新建.net core web解决方案,也可以右键该解决方案,通过管理解决方案Nuget包功能来找到。如下图:浏览中搜索Zxing第一个既是。选中安装即可。
可通过项目中依赖性查看相应包的引用。如图:
2.二维码生成
2.1前端页面
在login.cshtml页面中添加前端元素,主要是一个图片控件。
1 <div style="text-align:center">2 <div style="margin-top:20px">3 <span>扫码获取</span><br/>4 <img id="barcode" width="400" height="400" alt="扫码获取" src="Dynpass/GetBarCode"/>5 </div>6 </div>
src="Dynpass/GetBarCode"表示image数据从DynpassController的GetBarCode方法获取。
2.1后端代码
初始化界面以及二维码资源生成方法:
1 public class DynPassController : Controller 2 { 3 private readonly BarCodeVue _barCodeContent;// 4 public DynPassController(IOptions<BarCodeVue> content) 5 { 6 this._barCodeContent = content.Value; 7 } 8 9 /// <summary>10 /// 初始化显示页面11 /// </summary>12 /// <returns></returns>13 [HttpGet]14 public IActionResult Login()15 {16 return View();17 }18 19 /// <summary>20 /// Svn显示==请求获取二维码资源21 /// </summary>22 /// <returns></returns>23 [HttpGet]24 public ActionResult GetBarCode()25 {26 var bar= _barCodeContent != null ? _barCodeContent.BarCode : "扫码获取";27 Bitmap bitmap = MyZxingBarcode.GenerateBitmapCode(bar);//扫码获取28 System.IO.MemoryStream ms = new System.IO.MemoryStream();29 bitmap.Save(ms, ImageFormat.Bmp);30 return File(ms.GetBuffer(), "image/png");//31 }32 }
DynPassController生成二维码的内容即_barCodeContent值由core框架依赖注入(构造该对象时通过构造函数传入)。所以需在ConfigureServices中进行注册。Barcode类结构
1 public class BarCodeVue2 {3 public string BarCode { get; set; }4 }
二维码内容注册
具体步骤:
1.在appsettings.json中添加节点。
1 { 2 "Logging": { 3 "LogLevel": { 4 "Default": "Information", 5 "Microsoft": "Warning", 6 "Microsoft.Hosting.Lifetime": "Information" 7 } 8 }, 9 "BarCodeVue": {10 "BarCode":"MyBarCode"11 },12 13 "AllowedHosts": "*"14 }
2.BarCodeVue注册
在Program类中ConfigureServices方法中通过Configure注册。
1 // This method gets called by the runtime. Use this method to add services to the container. 2 public void ConfigureServices(IServiceCollection services) 3 { 4 services.Configure<CookiePolicyOptions>(options => 5 { 6 // This lambda determines whether user consent for non-essential cookies is needed for a given request. 7 options.CheckConsentNeeded = context => true; 8 }); 9 services.Configure<BarCodeVue>(Configuration.GetSection("BarCodeVue"));//注册BarCodeVue键值10 //services.AddMvc().AddViewOptions(options => options.HtmlHelperOptions.ClientValidationEnabled = true);11 services.AddControllersWithViews()12 .AddNewtonsoftJson();13 services.AddRazorPages();14 }
3.生成二维码方法MyZxingBarcode类
public class MyZxingBarcode {/// <summary>/// 生成二维码,保存成图片/// </summary>public static Bitmap GenerateBitmapCode(string content) {var writer = new BarcodeWriterPixelData(); writer.Format = BarcodeFormat.QR_CODE; QrCodeEncodingOptions options = new QrCodeEncodingOptions(); options.DisableECI = true;//设置内容编码options.CharacterSet = "UTF-8";//设置二维码的宽度和高度options.Width = 300; options.Height = 300;//设置二维码的边距,单位不是固定像素options.Margin = 1; writer.Options = options;// var pixdata = writer.Write(content);var map = PixToBitmap(pixdata.Pixels, pixdata.Width, pixdata.Height);//string filename = @"D:\generate1.png";//map.Save(filename, ImageFormat.Bmp);return map; }/// <summary> /// 将一个字节数组转换为位图 /// </summary> /// <param name="pixValue">显示字节数组</param> /// <param name="width">图像宽度</param> /// <param name="height">图像高度</param> /// <returns>位图</returns> private static Bitmap PixToBitmap(byte[] pixValue, int width, int height) {//// 申请目标位图的变量,并将其内存区域锁定var m_currBitmap = new Bitmap(width, height, PixelFormat.Format32bppArgb);var m_rect = new Rectangle(0, 0, width, height);var m_bitmapData = m_currBitmap.LockBits(m_rect, ImageLockMode.WriteOnly, PixelFormat.Format32bppRgb); IntPtr iptr = m_bitmapData.Scan0; // 获取bmpData的内存起始位置 //// 用Marshal的Copy方法,将刚才得到的内存字节数组复制到BitmapData中 System.Runtime.InteropServices.Marshal.Copy(pixValue, 0, iptr, pixValue.Length); m_currBitmap.UnlockBits(m_bitmapData);//// 算法到此结束,返回结果 return m_currBitmap;////初始化条形码格式,宽高,以及PureBarcode=true则不会留白框//var writer = new BarcodeWriterPixelData//{// Format = BarcodeFormat.QR_CODE,// Options = new ZXing.Common.EncodingOptions { Height = 31, Width = 167, PureBarcode = true, Margin = 1 }//};//var pixelData = writer.Write("123236699555555555559989966");//using (var bitmap = new Bitmap(pixelData.Width, pixelData.Height, PixelFormat.Format32bppRgb))//using (var ms = new MemoryStream())//{// var bitmapData = bitmap.LockBits(new Rectangle(0, 0, pixelData.Width, pixelData.Height),// System.Drawing.Imaging.ImageLockMode.WriteOnly, PixelFormat.Format32bppRgb);// try// {// // we assume that the row stride of the bitmap is aligned to 4 byte multiplied by the width of the image// System.Runtime.InteropServices.Marshal.Copy(pixelData.Pixels, 0, bitmapData.Scan0, pixelData.Pixels.Length);// }// finally// {// bitmap.UnlockBits(bitmapData);// }// // save to stream as PNG// bitmap.Save(ms, ImageFormat.Png);// Image image = Bitmap.FromStream(ms, true);// image.Save(@"D:\content.png");// byte[] bytes = ms.GetBuffer();//} } }
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