index.cshtml 页面中

@ViewData["Title"] 就可以得到字符 "未命名"

index.cshtml 使用 _Layout.cshtml 页

index.cshtml 可以跳转到 ProductCenter.cshtml 页

ProductCenter.cshtml 使用 _Layout.cshtml 页

public async Task< IActionResult > ProductCenter()    
       //注释   ViewData["Title"] 后 ProductCenter.cshtml  页无法得到 字符 "未命名"  
       //   ViewData["Title"] = "未命名";             
        return View();  
如果想每一个页面都可以得到 字符 "未命名" 。    
那么每个IActionResult< IActionResult > 都需要有 ViewData["Title"] = "未命名";     
这种方法太麻烦，有没有更简单的方法。    
			 
Hi @长生猫  ,    
You could use session to transfer data from content page to layout page. Please refer the following steps:    
 Configure session state        Add a call to AddSession in ConfigureServices  

    Add a call to UseSession in Configure.  
 Configure the     

    Add a call to AddHttpContextAccessor() in the ConfigureServices: to access HttpContext and access sesson value in the View Page.      After the above configuration, the result as below:  
public void ConfigureServices(IServiceCollection services)  
    services.AddDistributedMemoryCache();  
    services.AddSession(options =>  
        options.Cookie.Name = ".AdventureWorks.Session";  
        options.IdleTimeout = TimeSpan.FromMinutes(10);  
        options.Cookie.HttpOnly = true;  
        options.Cookie.IsEssential = true;  
    services.AddHttpContextAccessor()  
    //services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();  
    services.AddControllersWithViews();  
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.  
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)  
    if (env.IsDevelopment())  
        app.UseDeveloperExceptionPage();  
        app.UseExceptionHandler("/Home/Error");  
        // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.  
        app.UseHsts();  
    app.UseHttpsRedirection();  
    app.UseStaticFiles();  
    app.UseRouting();  
    app.UseAuthorization();  
    app.UseSession();  
    app.UseEndpoints(endpoints =>  
        endpoints.MapControllerRoute(  
            name: "default",  
            pattern: "{controller=Home}/{action=Index}/{id?}");  
 Set Session value in the Controller:    
public IActionResult Index()  
    if (string.IsNullOrEmpty(HttpContext.Session.GetString("Title")))  
        HttpContext.Session.SetString("Title", "Layout Title");  
    return View();  
public IActionResult Privacy()  
    return View();  
 Accesss the Session value in the Layout Page:        Add the following code in the head:  
@using Microsoft.AspNetCore.Http  
@inject IHttpContextAccessor HttpContextAccessor    
    Add the following code in the body:  
@if (!string.IsNullOrEmpty(HttpContextAccessor.HttpContext.Session.GetString("Title")))  
    var value = HttpContextAccessor.HttpContext.Session.GetString("Title");  
    <span>@value</span>  
The result as below: In the Index Action method, we set the session value, in the Privacy action method, there is no need to set session value again.     
[Note]     
 In the above sample, we are using session to store the value, please pay more attention to the Session Expired time. More detail information, see Session state.      
 Currently in Microsoft Q&A we only support English, could you please edit your question into English? Thanks for your understanding.    
If the answer is helpful, please click "Accept Answer" and upvote it.     

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Best Regards,    

Dillion