ASP.NET CORE 入门教程

第一课 基本概念

• 基本概念
  • Asp.Net Core Mvc是.NET Core平台下的一种Web应用开发框架
    • 符合Web应用特点
    • .NET Core跨平台解决方案
    • MVC设计模式的一种实现
• 环境准备
  • 安装最新版Visual Studio 2017
  • 安装最新版.NET Core Sdk

第二课 控制器的介绍

• 控制器定义方式：
  • 命名以Controller结尾
  • 使用ControllerAttribute标注

    public class TestController : Controller
    {

    }

    [Controller]
    public class Test : Controller
    {

    }

• 默认路由规则

  • 域名/控制器类/方法
  • {Domain}/{Controller}/{Action}

• 数据形式

  • QueryString: ?name=zhangsan&age=22
  • Form
  • Cookie
  • Session
  • Header

• HttpRequest

  • HttpRequest 是用户请求对象
  • 提供获取请求数据的属性
    • Cookies,Headers,Query,QueryString,Form

        public IActionResult Hello()
        {
            // Query
            var name = Request.Query["name"];
            // QueryString
            var query = Request.QueryString.Value;
            // Form
            var username = Request.Form["username"];
            // Cookies
            var cookie = Request.Cookies["item"];
            // Headers
            var headers = Request.Headers["salt"];

            return Content("Hello");
        }

• HttpContext
  • HttpContext是用户请求上下文
  • 提供Session属性获取Session对象
    • Session.Set 设置
    • Session.Remove 移除
    • Session.TryGetValue 获取数据

        public IActionResult Hello()
        {       
            // byte[]
            HttpContext.Session.Set("byte", new byte[] { 1, 2, 3, 4, 5 });
            var bytes = HttpContext.Session.Get("byte");
            // string
            HttpContext.Session.SetString("name", "tom");
            var name = HttpContext.Session.GetString("name");
            // int
            HttpContext.Session.SetInt32("id", 20);
            var id = HttpContext.Session.GetInt32("id");
            HttpContext.Session.Remove("name");
            HttpContext.Session.Clear();
            
            return Content("Hello");
        }

• 数据绑定
  • 把用户请求的数据绑定到控制器方法的参数上
  • 支持简单类型与自定义类型
  • 绑定规则是请求数据名称与参数名称一致
    • 如查询字符串key名称跟参数一致
    • Form表单名称跟参数一致

        public IActionResult Hello(RequestModel request,int? age)
        {
            // 查询字符串
            var test = Request.Query["test"];
            // 简单类型
            var userAge = age;
            // 自定义类型
            var name = request.Name;

            return Content("Hello");
        }

        public class RequestModel
        {
            public string Name { get; set; }       
        }

• 内容补充
  • 如果以Controller结尾的都是控制器，那如果程序里面由一些业务命名的时候也是以Controller结尾，怎么办？
  • NonControllerAttribute

    /// <summary>
    /// 拍卖师控制类
    /// </summary>
    [NonController]
    public class AuctionController
    {

    }   

• 常用特性

        public IActionResult Say(
            [FromForm]string name,
            [FromQuery]int age,
            [FromHeader] string salt,
            [FromBody] string content
            )
        {
            return View();
        }

• 特性参数

  • 通过特性修饰参数来影响绑定逻辑
  • 灵活扩展

• IActionResult

  • 动作结果接口
  • 具体实现
    • JsonResult：返回JSON结构数据
    • RedirectResult：跳转到新地址
    • FileResult：返回文件
    • ViewResult：返回视图内容
    • ContentResult：文本内容

第三课 视图与表单

• 数据传递
  • ViewData
  • ViewBag
  • tempData
  • Model
  • Session
  • Cache

• Cache
  • 与.NET Framework时代不同，一种全新实现
  • IMemoryCache接口
  • 依赖注入方式获取
  • IMemoryCache.Get/Set操作数据

    [Controller]
    public class Test : Controller
    {
        private readonly IMemoryCache _cache;

        public Test(IMemoryCache memoryCache)
        {
            this._cache = memoryCache;   
        }

        public IActionResult ReadCache()
        {
            _cache.Set("name","tom");
            _cache.Get("name");

            _cache.Set("age",30);
            _cache.Get("age");

            User tom = new User(){ Name = "admin",Pwd = "123456"};
            _cache.Set<User>("user",tom);
            _cache.Get<User>("user");
            return Content("ok");
        }
    }

    public class User
    {
        public string Name { get; set; }
        public string Pwd { get; set; }
    }

• ViewStart
  • 以_ViewStart.cshtml命名，固定名称，不能更换
  • 一般放在视图所在目录的根目录下
  • 自动执行，无需手工调用
  • 不要再ViewStart中做大量的业务操作
• ViewImport
  • 以_ViewImport.cshtml命名，固定名称，不能更换
  • 只作引入操作
  • 一般放在视图所在目录的根目录下
  • 自动执行，无需手工调用
  • 视图中可以使用@using关键字引入所需命名空间
  • 通过ViewImport做全局性的命名空间引入，减少在每个页面中引入的工作量

第四课 数据验证

• 数据验证特性ValidationAttribute

  public abstract class ValidationAttribute : Attribute
  {
    /// <summary>Initializes a new instance of the <see cref="T:System.ComponentModel.DataAnnotations.ValidationAttribute"></see> class.</summary>
    protected ValidationAttribute();

    /// <summary>Initializes a new instance of the <see cref="T:System.ComponentModel.DataAnnotations.ValidationAttribute"></see> class by using the function that enables access to validation resources.</summary>
    /// <param name="errorMessageAccessor">The function that enables access to validation resources.</param>
    /// <exception cref="T:System.ArgumentNullException"><paramref name="errorMessageAccessor">errorMessageAccessor</paramref> is null.</exception>
    protected ValidationAttribute(Func<string> errorMessageAccessor);

    /// <summary>Initializes a new instance of the <see cref="T:System.ComponentModel.DataAnnotations.ValidationAttribute"></see> class by using the error message to associate with a validation control.</summary>
    /// <param name="errorMessage">The error message to associate with a validation control.</param>
    protected ValidationAttribute(string errorMessage);

    /// <summary>Gets or sets an error message to associate with a validation control if validation fails.</summary>
    /// <returns>The error message that is associated with the validation control.</returns>
    public string ErrorMessage { get; set; }

    /// <summary>Gets or sets the error message resource name to use in order to look up the <see cref="P:System.ComponentModel.DataAnnotations.ValidationAttribute.ErrorMessageResourceType"></see> property value if validation fails.</summary>
    /// <returns>The error message resource that is associated with a validation control.</returns>
    public string ErrorMessageResourceName { get; set; }

    /// <summary>Gets or sets the resource type to use for error-message lookup if validation fails.</summary>
    /// <returns>The type of error message that is associated with a validation control.</returns>
    public Type ErrorMessageResourceType { get; set; }

    /// <summary>Gets the localized validation error message.</summary>
    /// <returns>The localized validation error message.</returns>
    protected string ErrorMessageString { get; }

    /// <summary>Gets a value that indicates whether the attribute requires validation context.</summary>
    /// <returns>true if the attribute requires validation context; otherwise, false.</returns>
    public virtual bool RequiresValidationContext { get; }

    /// <summary>Applies formatting to an error message, based on the data field where the error occurred.</summary>
    /// <param name="name">The name to include in the formatted message.</param>
    /// <returns>An instance of the formatted error message.</returns>
    public virtual string FormatErrorMessage(string name);

    /// <summary>Checks whether the specified value is valid with respect to the current validation attribute.</summary>
    /// <param name="value">The value to validate.</param>
    /// <param name="validationContext">The context information about the validation operation.</param>
    /// <returns>An instance of the <see cref="System.ComponentModel.DataAnnotations.ValidationResult"></see> class.</returns>
    public ValidationResult GetValidationResult(
      object value,
      ValidationContext validationContext);

    /// <summary>Determines whether the specified value of the object is valid.</summary>
    /// <param name="value">The value of the object to validate.</param>
    /// <returns>true if the specified value is valid; otherwise, false.</returns>
    public virtual bool IsValid(object value);

    /// <summary>Validates the specified value with respect to the current validation attribute.</summary>
    /// <param name="value">The value to validate.</param>
    /// <param name="validationContext">The context information about the validation operation.</param>
    /// <returns>An instance of the <see cref="System.ComponentModel.DataAnnotations.ValidationResult"></see> class.</returns>
    protected virtual ValidationResult IsValid(
      object value,
      ValidationContext validationContext);

    /// <summary>Validates the specified object.</summary>
    /// <param name="value">The object to validate.</param>
    /// <param name="validationContext">The <see cref="T:System.ComponentModel.DataAnnotations.ValidationContext"></see> object that describes the context where the validation checks are performed. This parameter cannot be null.</param>
    /// <exception cref="T:System.ComponentModel.DataAnnotations.ValidationException">Validation failed.</exception>
    public void Validate(object value, ValidationContext validationContext);

    /// <summary>Validates the specified object.</summary>
    /// <param name="value">The value of the object to validate.</param>
    /// <param name="name">The name to include in the error message.</param>
    /// <exception cref="T:System.ComponentModel.DataAnnotations.ValidationException"><paramref name="value">value</paramref> is not valid.</exception>
    public void Validate(object value, string name);
  }

• 常用数据验证

  • RequiredAttribute
  • RegularExpressionAttribute
  • CompareAttribute
  • RangeAttribute
  • MaxAttribute
  • MinAttribute
  • StringLengthAttribute
  • DataTypeAttribute

• 服务器端使用

  • 使用包含验证规则的类接收数据
  • 使用ModelState.IsValid判断是否符合要求

• 前端使用

  • 定义强类型视图并传递包含验证规则的业务数据模型
  • 使用HtmlHelper.ValidationFor初始前端验证规则
  • 使用HtmlHelper.ValidationMessageFor生成提示文字

    public class UserLogin
    {
        [Required(ErrorMessage = "用户名不能为空")]
        [StringLength(10,ErrorMessage = "用户名长度不能超过10位")]
        public string UserName { get; set; }
          
        //[Required(ErrorMessage = "密码不能为空")]
        [StringLength(6,ErrorMessage = "密码长度不能超过6位")]
        public string Password { get; set; }
    }

    public class FormController : Controller
    {
        public IActionResult Index()
        {
            return View(new UserLogin());
        }

        public IActionResult PostData(UserLogin login)
        {
            return Content(ModelState.IsValid?"数据有效":"数据无效");
        }
    }

@model Lesson2.Models.UserLogin
@{
    Layout = null;
}

<!DOCTYPE html>

<html>
<head>
    <meta name="viewport" content="width=device-width" />
    <title>Index</title>
    <script src="~/lib/jquery/dist/jquery.min.js"></script>
    <script src="~/lib/jquery-validation/dist/jquery.validate.min.js"></script>
    <script src="~/lib/jquery-validation-unobtrusive/jquery.validate.unobtrusive.min.js"></script>
</head>
<body>
    <form asp-action="PostData" method="post">
        <table>
            <tr>
                <td>用户名</td>
                <td>@Html.TextBoxFor(m => m.UserName)</td>
                <td>@Html.ValidationMessageFor(m => m.UserName)</td>
            </tr>
            <tr>
                <td>密码</td>
                <td>@Html.PasswordFor(m => m.Password)</td>
                <td>@Html.ValidationMessageFor(m => m.Password)</td>
            </tr>
            <tr>
                <td></td>
                <td><input type="submit" value="登录" /></td>
                <td></td>
            </tr>
        </table>
    </form>
</body>
</html>

第五课 路由规则

• 路由

  • 定义用户请求与控制器方法之前的映射关系

• 路由配置

  • IRouteBuilder
    • 通过MapRoute方法配置路由模板

    app.UseMvc(routes =>
    {
        routes.MapRoute(
            name: "default",
            template: "{controller=Home}/{action=Index}/{id?}");

        routes.MapRoute(
            name: "admin_default",
            template: "admin/{controller=Home}/{action=Index}/{id?}");
    });

• RouteAttribute
  • 应用在控制器及方法上
  • 通过Template属性配置路由模板

    [Route("admin/form")]
    public class FormController : Controller
    {
        [Route("index")]
        public IActionResult Index()
        {
            return View(new UserLogin());
        }

        public IActionResult PostData(UserLogin login)
        {
            return Content(ModelState.IsValid?"数据有效":"数据无效");
        }
    }

• 路由约束
  • 对路由数据进行约束
  • 只有约束满足条件才能匹配成功

• 路由数据
  • 路由数据也是请求数据的一部分
  • 路由数据与表单数据一样，也可以绑定到参数上
  • 默认是通过名称进行匹配，也可以通过FormRouteAttribute匹配参数与路由数据的映射关系

    public IActionResult Index([FromRoute] int? id)
    {
        return View();
    }

第六课 应用发布与部署

• 发布
  • 发布方法
    • 使用Visual Studio发布应用：项目右键 -> 发布 -> 发布方式选择...
    • 使用dotnet publish命令行工具发布：dotnet publish --configuration Release --runtime win7-x64 --output c:\svc
• 视图预编译
  • 少了运行时编译过程，启动速度快
  • 预编译后，整个程序包更小
  • 可以通过MvcRazorCompileOnPublish配置是否开启，默认是开启状态
    • 关闭视图预编译：
      • 打开项目的.csproj文件
      • 配置MvcRazorCompileOnPublish为false

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>netcoreapp2.1</TargetFramework>
    <!-- 关闭视图预编译 -->
    <MvcRazorCompileOnPublish>false</MvcRazorCompileOnPublish>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.App" />
    <PackageReference Include="Microsoft.AspNetCore.Razor.Design" Version="2.1.2" PrivateAssets="All" />
    <PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="2.1.1" />
  </ItemGroup>

</Project>

• 部署
  • IIS 部署
    • 目标机器安装对应版本的.NET Core Sdk
    • 安装.NET Core Windows Server 托管程序
    • 应用程序池的“.NET CLR版本”设置为“无托管代码”
    • image
  • 自宿主发布
    • 发布成一个exe直接运行
    • 不用依赖IIS
    • RuntimeIdentifier
    • .NET Core RID Catalog

<!-- 依赖框架的部署 (FDD) -->
<PropertyGroup>
  <TargetFramework>netcoreapp2.2</TargetFramework>
  <RuntimeIdentifier>win7-x64</RuntimeIdentifier>
  <SelfContained>false</SelfContained>
  <IsTransformWebConfigDisabled>true</IsTransformWebConfigDisabled>
</PropertyGroup>
<!-- 独立部署 (SCD) -->
<PropertyGroup>
  <TargetFramework>netcoreapp2.2</TargetFramework>
  <RuntimeIdentifier>win7-x64</RuntimeIdentifier>
  <IsTransformWebConfigDisabled>true</IsTransformWebConfigDisabled>
</PropertyGroup>
    ...
    ...
    ...

源码地址

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