.NET MVC5专题（视图引擎详解）

在全局文件加如下代码

protected void Application_Start()
{
    string engineDescription = string.Join(",", ViewEngines.Engines.ToList().Select(v => v.ToString()));
    //清除默认视图引擎
    ViewEngines.Engines.Clear();
    //添加自己视图引擎
    ViewEngines.Engines.Add(new CustomViewEngine());
}

视图引擎的类

/// <summary>
/// 解决方案：
/// a 覆写的是FindView而不是CreateView(迟了),而且一定得set回去 Materal--66.6红包
/// b CreateView时直接修改path(狠人)   RGB--66.6红包
/// 注意不同的路径如_ViewStart
/// </summary>
public class CustomViewEngine : RazorViewEngine
{
    #region 构造函数
    public ElevenCustomViewEngine() : this(null)
    {
    }
    public ElevenCustomViewEngine(IViewPageActivator viewPageActivator) : base(viewPageActivator)
    {
        this.SetEngine("");
    }
    #endregion

    #region A
    public override ViewEngineResult FindView(ControllerContext controllerContext, string viewName, string masterName, bool useCache)
    {
        //if (controllerContext.HttpContext.Request.UserAgent.Contains("Chrome/74.0.3729.169"))
        //{
        //    this.SetEngine("Chrome");
        //}
        //else
        //{
        //    this.SetEngine("");//一定得有，因为只有一个Engine实例
        //}
        return base.FindView(controllerContext, viewName, masterName, useCache);
    }

    public override ViewEngineResult FindPartialView(ControllerContext controllerContext, string partialViewName, bool useCache)
    {
        //if (controllerContext.HttpContext.Request.UserAgent.Contains("Chrome/74.0.3729.169"))
        //{
        //    this.SetEngine("Chrome");
        //}
        //else
        //{
        //    this.SetEngine("");
        //}
        return base.FindPartialView(controllerContext, partialViewName, useCache);
    }
    #endregion


    #region B
    /// <summary>
    /// 
    /// </summary>
    /// <param name="controllerContext">可以为所欲为</param>
    /// <param name="partialPath"></param>
    /// <returns></returns>
    protected override IView CreatePartialView(ControllerContext controllerContext, string partialPath)
    {
        if (controllerContext.HttpContext.Request.UserAgent.Contains("Chrome/74.0.3729.169"))
        {
            partialPath = partialPath.Replace("/Views/", "/ChromeViews/");
        }
        return base.CreatePartialView(controllerContext, partialPath);
    }
    protected override IView CreateView(ControllerContext controllerContext, string viewPath, string masterPath)
    {
        if (controllerContext.HttpContext.Request.UserAgent.Contains("Chrome/74.0.3729.169"))
        {
            viewPath = viewPath.Replace("/Views/", "/ChromeViews/");
            masterPath = masterPath.Replace("/Views/", "/ChromeViews/");
        }
        return base.CreateView(controllerContext, viewPath, masterPath);
    }
    #endregion
    /// <summary>
    /// 把模板给换了
    /// </summary>
    /// <param name="browser"></param>
    private void SetEngine(string browser)
    {
        if (!string.IsNullOrWhiteSpace(browser))
        {
            base.AreaViewLocationFormats = new string[]
                        {
            "~/Areas/{2}/"+browser+"Views/{1}/{0}.cshtml",
            "~/Areas/{2}/"+browser+"Views/{1}/{0}.vbhtml",
            "~/Areas/{2}/"+browser+"Views/Shared/{0}.cshtml",
            "~/Areas/{2}/"+browser+"Views/Shared/{0}.vbhtml"
                        };
            base.AreaMasterLocationFormats = new string[]
            {
            "~/Areas/{2}/"+browser+"Views/{1}/{0}.cshtml",
            "~/Areas/{2}/"+browser+"Views/{1}/{0}.vbhtml",
            "~/Areas/{2}/"+browser+"Views/Shared/{0}.cshtml",
            "~/Areas/{2}/"+browser+"Views/Shared/{0}.vbhtml"
            };
            base.AreaPartialViewLocationFormats = new string[]
            {
            "~/Areas/{2}/"+browser+"Views/{1}/{0}.cshtml",
            "~/Areas/{2}/"+browser+"Views/{1}/{0}.vbhtml",
            "~/Areas/{2}/"+browser+"Views/Shared/{0}.cshtml",
            "~/Areas/{2}/"+browser+"Views/Shared/{0}.vbhtml"
            };
            base.ViewLocationFormats = new string[]
            {
            "~/"+browser+"Views/{1}/{0}.cshtml",
            "~/"+browser+"Views/{1}/{0}.vbhtml",
            "~/"+browser+"Views/Shared/{0}.cshtml",
            "~/"+browser+"Views/Shared/{0}.vbhtml"
            };
            base.MasterLocationFormats = new string[]
            {
            "~/"+browser+"Views/{1}/{0}.cshtml",
            "~/"+browser+"Views/{1}/{0}.vbhtml",
            "~/"+browser+"Views/Shared/{0}.cshtml",
            "~/"+browser+"Views/Shared/{0}.vbhtml"
            };
            base.PartialViewLocationFormats = new string[]
            {
            "~/"+browser+"Views/{1}/{0}.cshtml",
            "~/"+browser+"Views/{1}/{0}.vbhtml",
            "~/"+browser+"Views/Shared/{0}.cshtml",
            "~/"+browser+"Views/Shared/{0}.vbhtml"
            };
        }
        else
        {
            base.AreaViewLocationFormats = new string[]
       {
            "~/Areas/{2}/Views/{1}/{0}.cshtml",
            "~/Areas/{2}/Views/{1}/{0}.vbhtml",
            "~/Areas/{2}/Views/Shared/{0}.cshtml",
            "~/Areas/{2}/Views/Shared/{0}.vbhtml"
       };
            base.AreaMasterLocationFormats = new string[]
            {
            "~/Areas/{2}/Views/{1}/{0}.cshtml",
            "~/Areas/{2}/Views/{1}/{0}.vbhtml",
            "~/Areas/{2}/Views/Shared/{0}.cshtml",
            "~/Areas/{2}/Views/Shared/{0}.vbhtml"
            };
            base.AreaPartialViewLocationFormats = new string[]
            {
            "~/Areas/{2}/Views/{1}/{0}.cshtml",
            "~/Areas/{2}/Views/{1}/{0}.vbhtml",
            "~/Areas/{2}/Views/Shared/{0}.cshtml",
            "~/Areas/{2}/Views/Shared/{0}.vbhtml"
            };
            base.ViewLocationFormats = new string[]
            {
            "~/Views/{1}/{0}.cshtml",
            "~/Views/{1}/{0}.vbhtml",
            "~/Views/Shared/{0}.cshtml",
            "~/Views/Shared/{0}.vbhtml"
            };
            base.MasterLocationFormats = new string[]
            {
            "~/Views/{1}/{0}.cshtml",
            "~/Views/{1}/{0}.vbhtml",
            "~/Views/Shared/{0}.cshtml",
            "~/Views/Shared/{0}.vbhtml"
            };
            base.PartialViewLocationFormats = new string[]
            {
            "~/Views/{1}/{0}.cshtml",
            "~/Views/{1}/{0}.vbhtml",
            "~/Views/Shared/{0}.cshtml",
            "~/Views/Shared/{0}.vbhtml"
            };
            base.FileExtensions = new string[]
            {
            "cshtml",
            "vbhtml"
            };
        }
    }
}