asp.net core2.0 登录效果实现
基础
新建项目的,新建登录页的基本操作略,主要说下在实现登录过程碰到的问题,废话不多说,让我们进入主题。
验证码
asp.net.core2.0本身有提供system.drawing命名空间,但是没有Image,Graphics,Bitmap等对象的实现,只能引用第三方的dll来操作。
1、在vs的项目里打开nuget包管理器,搜索关键字“drawing",显示很多可用的包,选择安装"zkweb.system.drawing" 包
2、实现随机字符串的图片显示代码
public IActionResult ImgCode() { int Width = 100; int Height = 30; string chkCode = string.Empty; //颜色列表,用于验证码、噪线、噪点 Color[] color = { Color.Black, Color.Red, Color.Blue, Color.Green, Color.Orange, Color.Brown, Color.DarkBlue }; //字体列表,用于验证码 string[] font = { "Times New Roman", "MS Mincho", "Book Antiqua", "Gungsuh", "PMingLiU", "Impact" }; //验证码的字符集,去掉了一些容易混淆的字符 char[] character ={ '2', '3', '4', '5', '6', '8', '9', 'A', 'B', 'C', 'D', 'E','F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'R', 'S', 'T', 'W', 'X', 'Y' }; Random rnd = new Random(); //生成验证码字符串 for (int i = 0; i < 4; i++) { chkCode += character[rnd.Next(character.Length)]; } //保存验证码的Cookie //HttpCookie anycookie = new HttpCookie("validateCookie"); //anycookie.Values.Add("ChkCode", chkCode); //HttpContext.Current.Response.Cookies["validateCookie"].Values["ChkCode"] = chkCode; Bitmap bmp = new Bitmap(Width, Height); Graphics g = Graphics.FromImage(bmp); g.Clear(Color.White); //画噪线 for (int i = 0; i < 2; i++) { int x1 = rnd.Next(Width); int y1 = rnd.Next(Height); int x2 = rnd.Next(Width); int y2 = rnd.Next(Height); Color clr = color[rnd.Next(color.Length)]; g.DrawLine(new Pen(clr), x1, y1, x2, y2); } //画验证码字符串 for (int i = 0; i < chkCode.Length; i++) { string fnt = font[rnd.Next(font.Length)]; Font ft = new Font(fnt, 16, FontStyle.Bold); Color clr = color[rnd.Next(color.Length)]; g.DrawString( chkCode[i].ToString(), ft, new SolidBrush(clr), (float)i * 20 + 20, (float)6 ); } //画噪点 for (int i = 0; i < 10; i++) { int x = rnd.Next(bmp.Width); int y = rnd.Next(bmp.Height); Color clr = color[rnd.Next(color.Length)]; bmp.SetPixel(x, y, clr); } //将验证码图片写入内存流,并将其以"image/Png" 格式输出 MemoryStream ms = new MemoryStream(); try { bmp.Save(ms, ImageFormat.Png); HttpContext.Session.SetString("chkCode", chkCode); Response.Body.Dispose(); return File(ms.ToArray(), @"image/png"); } finally { //显式释放资源 bmp.Dispose(); g.Dispose(); } }
3、运行webapplication正常,验证码没有显示出来,调试发现有Session的错误提示,编译时能正常通过,运行提示“Session has not been configured for this application or request.”,在startup.cs使用session服务
,代码如下:
public void ConfigureServices(IServiceCollection services) { services.AddMvc().AddSessionStateTempDataProvider(); services.AddSession(); } // This method gets called by the runtime. Use this method to configure the HTTP request pipeline. public void Configure(IApplicationBuilder app, IHostingEnvironment env) { if (env.IsDevelopment()) { app.UseDeveloperExceptionPage(); app.UseBrowserLink(); } else { app.UseExceptionHandler("/Home/Error"); } app.UseStaticFiles(); app.UseSession(); app.UseMvc(routes => { routes.MapRoute( name: "default", template: "{controller=Home}/{action=Index}/{id?}"); }); }
4、编译,刷新页面,显示验证码效果:
登录动作实现
登录后台,用session保存登录后用户对象信息,session方法里没有发现有能保存值是对象形式,这就有点尴尬了,难道用户的信息用多个key分别去存储,这有点不科学啊,肯定有简单的方式实现。