一、前言

最近做项目的时候，使用Util进行开发，使用Razor写前端页面。初次使用感觉还是不大习惯，之前都是前后端分离的方式开发的，但是使用Util封装后的Angular后，感觉开发效率还是杠杠滴。

二、问题

在发布代码的时候，Webpack打包异常，提示是缺少了某些Html文件，我看了下相应的目录，发现目录缺少了部分Html文件，然后就问了何镇汐大大，给出的解决方案是，每个页面都需要访问一下才能生成相应的Html静态文件。这时候就产生了疑虑，是否有一种方式能获取所有路由，然后只需访问一次即可生成所有的Html页面。

三、解决方案

3.1 每次访问生成Html

解决方案思路：

继承ActionFilterAttribute特性，重写执行方法
访问的时候判断访问的Result是否ViewResult，如果是方可生成Html
从RazorViewEngine中查找到View后进行渲染

/// <summary>

/// 生成Html静态文件

/// </summary>

public class HtmlAttribute : ActionFilterAttribute {

/// <summary>

/// 生成路径，相对根路径，范例：/Typings/app/app.component.html

/// </summary>

public string Path { get; set; }

/// <summary>

/// 路径模板，范例：Typings/app/{area}/{controller}/{controller}-{action}.component.html

/// </summary>

public string Template { get; set; }

/// <summary>

/// 执行生成

/// </summary>

public override async Task OnResultExecutionAsync( ResultExecutingContext context, ResultExecutionDelegate next ) {

await WriteViewToFileAsync( context );

await base.OnResultExecutionAsync( context, next );

}

/// <summary>

/// 将视图写入html文件

/// </summary>

private async Task WriteViewToFileAsync( ResultExecutingContext context ) {

try {

var html = await RenderToStringAsync( context );

if( string.IsNullOrWhiteSpace( html ) )

return;

var path = Util.Helpers.Common.GetPhysicalPath( string.IsNullOrWhiteSpace( Path ) ? GetPath( context ) : Path );

var directory = System.IO.Path.GetDirectoryName( path );

if( string.IsNullOrWhiteSpace( directory ) )

return;

if( Directory.Exists( directory ) == false )

Directory.CreateDirectory( directory );

File.WriteAllText( path, html );

}

catch( Exception ex ) {

ex.Log( Log.GetLog().Caption( "生成html静态文件失败" ) );

}

/// <summary>

/// 渲染视图

/// </summary>

protected async Task<string> RenderToStringAsync( ResultExecutingContext context ) {

string viewName = "";

object model = null;

if( context.Result is ViewResult result ) {

viewName = result.ViewName;

viewName = string.IsNullOrWhiteSpace( viewName ) ? context.RouteData.Values["action"].SafeString() : viewName;

model = result.Model;

}

var razorViewEngine = Ioc.Create<IRazorViewEngine>();

var tempDataProvider = Ioc.Create<ITempDataProvider>();

var serviceProvider = Ioc.Create<IServiceProvider>();

var httpContext = new DefaultHttpContext { RequestServices = serviceProvider };

var actionContext = new ActionContext( httpContext, context.RouteData, new ActionDescriptor() );

using( var stringWriter = new StringWriter() ) {

var viewResult = razorViewEngine.FindView( actionContext, viewName, true );

if( viewResult.View == null )

throw new ArgumentNullException( $"未找到视图： {viewName}" );

var viewDictionary = new ViewDataDictionary( new EmptyModelMetadataProvider(), new ModelStateDictionary() ) { Model = model };

var viewContext = new ViewContext( actionContext, viewResult.View, viewDictionary, new TempDataDictionary( actionContext.HttpContext, tempDataProvider ), stringWriter, new HtmlHelperOptions() );

await viewResult.View.RenderAsync( viewContext );

return stringWriter.ToString();

}

/// <summary>

/// 获取Html默认生成路径

/// </summary>

protected virtual string GetPath( ResultExecutingContext context ) {

var area = context.RouteData.Values["area"].SafeString();

var controller = context.RouteData.Values["controller"].SafeString();

var action = context.RouteData.Values["action"].SafeString();

var path = Template.Replace( "{area}", area ).Replace( "{controller}", controller ).Replace( "{action}", action );

return path.ToLower();

}

3.2 一次访问生成所有Html

解决方案思路：

获取所有已注册的路由
获取使用RazorHtml自定义特性的路由
忽略Api接口的路由
构建RouteData信息，用于在RazorViewEngine中查找到相应的视图
构建ViewContext用于渲染出Html字符串
将渲染得到的Html字符串写入文件

获取所有注册的路由，此处是比较重要的，其他地方也可以用到。

/// <summary>

/// 获取所有路由信息

/// </summary>

/// <returns></returns>

public IEnumerable<RouteInformation> GetAllRouteInformations()

{

List<RouteInformation> list = new List<RouteInformation>();

var actionDescriptors = this._actionDescriptorCollectionProvider.ActionDescriptors.Items;

foreach (var actionDescriptor in actionDescriptors)

{

RouteInformation info = new RouteInformation();

if (actionDescriptor.RouteValues.ContainsKey("area"))

{

info.AreaName = actionDescriptor.RouteValues["area"];

}

// Razor页面路径以及调用

if (actionDescriptor is PageActionDescriptor pageActionDescriptor)

{

info.Path = pageActionDescriptor.ViewEnginePath;

info.Invocation = pageActionDescriptor.RelativePath;

}

// 路由属性路径

if (actionDescriptor.AttributeRouteInfo != null)

{

info.Path = $"/{actionDescriptor.AttributeRouteInfo.Template}";

}

// Controller/Action 的路径以及调用

if (actionDescriptor is ControllerActionDescriptor controllerActionDescriptor)

{

if (info.Path.IsEmpty())

{

info.Path =

$"/{controllerActionDescriptor.ControllerName}/{controllerActionDescriptor.ActionName}";

}

var controllerHtmlAttribute = controllerActionDescriptor.ControllerTypeInfo.GetCustomAttribute<RazorHtmlAttribute>();

if (controllerHtmlAttribute != null)

{

info.FilePath = controllerHtmlAttribute.Path;

info.TemplatePath = controllerHtmlAttribute.Template;

}

var htmlAttribute = controllerActionDescriptor.MethodInfo.GetCustomAttribute<RazorHtmlAttribute>();

if (htmlAttribute != null)

{

info.FilePath = htmlAttribute.Path;

info.TemplatePath = htmlAttribute.Template;

}

info.ControllerName = controllerActionDescriptor.ControllerName;

info.ActionName = controllerActionDescriptor.ActionName;

info.Invocation = $"{controllerActionDescriptor.ControllerName}Controller.{controllerActionDescriptor.ActionName}";

}

info.Invocation += $"({actionDescriptor.DisplayName})";

list.Add(info);

}

return list;

}

生成Html静态文件

/// <summary>

/// 生成Html文件

/// </summary>

/// <returns></returns>

public async Task Generate()

{

foreach (var routeInformation in _routeAnalyzer.GetAllRouteInformations())

{

// 跳过API的处理

if (routeInformation.Path.StartsWith("/api"))

{

continue;

}

await WriteViewToFileAsync(routeInformation);

}

/// <summary>

/// 渲染视图为字符串

/// </summary>

/// <param name="info">路由信息</param>

/// <returns></returns>

public async Task<string> RenderToStringAsync(RouteInformation info)

{

var razorViewEngine = Ioc.Create<IRazorViewEngine>();

var tempDataProvider = Ioc.Create<ITempDataProvider>();

var serviceProvider = Ioc.Create<IServiceProvider>();

var routeData = new RouteData();

if (!info.AreaName.IsEmpty())

{

routeData.Values.Add("area", info.AreaName);

}

if (!info.ControllerName.IsEmpty())

{

routeData.Values.Add("controller", info.ControllerName);

}

if (!info.ActionName.IsEmpty())

{

routeData.Values.Add("action", info.ActionName);

}

var httpContext = new DefaultHttpContext { RequestServices = serviceProvider };

var actionContext = new ActionContext(httpContext, routeData, new ActionDescriptor());

var viewResult = razorViewEngine.FindView(actionContext, info.ActionName, true);

if (!viewResult.Success)

{

throw new InvalidOperationException($"找不到视图模板 {info.ActionName}");

}

using (var stringWriter = new StringWriter())

{

var viewDictionary = new ViewDataDictionary(new EmptyModelMetadataProvider(), new ModelStateDictionary());

var viewContext = new ViewContext(actionContext, viewResult.View, viewDictionary, new TempDataDictionary(actionContext.HttpContext, tempDataProvider), stringWriter, new HtmlHelperOptions());

await viewResult.View.RenderAsync(viewContext);

return stringWriter.ToString();

}

/// <summary>

/// 将视图写入文件

/// </summary>

/// <param name="info">路由信息</param>

/// <returns></returns>

public async Task WriteViewToFileAsync(RouteInformation info)

{

try

{

var html = await RenderToStringAsync(info);

if (string.IsNullOrWhiteSpace(html))

return;

var path = Utils.Helpers.Common.GetPhysicalPath(string.IsNullOrWhiteSpace(info.FilePath) ? GetPath(info) : info.FilePath);

var directory = System.IO.Path.GetDirectoryName(path);

if (string.IsNullOrWhiteSpace(directory))

return;

if (Directory.Exists(directory) == false)

Directory.CreateDirectory(directory);

File.WriteAllText(path, html);

}

catch (Exception ex)

{

ex.Log(Log.GetLog().Caption("生成html静态文件失败"));

}

protected virtual string GetPath(RouteInformation info)

{

var area = info.AreaName.SafeString();

var controller = info.ControllerName.SafeString();

var action = info.ActionName.SafeString();

var path = info.TemplatePath.Replace("{area}", area).Replace("{controller}", controller).Replace("{action}", action);

return path.ToLower();

}

四、使用方式

MVC控制器配置
Startup配置
一次性生成方式，调用一次接口即可

五、源码地址

Util: https://github.com/dotnetcore/Util

Bing.NetCore: https://github.com/bing-framework/Bing.NetCore

Razor生成静态Html文件：https://github.com/dotnetcore/Util/tree/master/src/Util.Webs/Razors 或者 https://github.com/bing-framework/Bing.NetCore/tree/master/src/Bing.Webs/Razors