我正试图在控制器中使用Microsoft.AspNetCore.Mvc.ActionContext，但我收到了这个错误，甚至认为我在MyController中进行了DI。。我不知道如何修复，请帮助
public class MyController : Controller
{
private readonly IWebHostEnvironment _hostEnvironment;
private readonly ActionContext _actionContext;
public StudentsController(
IWebHostEnvironment hostEnvironment,
ActionContext actionContext)
{
_hostEnvironment = hostEnvironment;
_actionContext = actionContext;
}
在这里，我试图访问控制器方法中的ActionContext：
[HttpPost]
public async Task<IActionResult> RegistrationPdf()
{
string wwwRootPath = _hostEnvironment.WebRootPath;
ViewAsPdf pdf = new ViewAsPdf("RegistrationPdf")
{
FileName = "RegistrationPdf.pdf",
};
byte[] pdfData = pdf.BuildFile(_actionContext).Result;
string fullPath = @"\Files" + pdf.FileName;
using (var fileStream = new FileStream(fullPath, FileMode.Create, FileAccess.Write))
{
fileStream.Write(pdfData, 0, pdfData.Length);
}
return RedirectToAction("Registration");
}
启动.cs
namespace Student
{
public class Startup
{
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
services.AddDbContext<ApplicationDbContext>(options =>
options.UseSqlServer(
Configuration.GetConnectionString("DefaultConnection")));
services.AddIdentity<IdentityUser, IdentityRole>()
.AddDefaultTokenProviders()
.AddDefaultUI()
.AddEntityFrameworkStores<ApplicationDbContext>();
services.Configure<IdentityOptions>(options =>
{
options.Password.RequireDigit = true;
options.Lockout.AllowedForNewUsers = true;
});
services.ConfigureApplicationCookie(options =>
{
ptions.SlidingExpiration = true;
});
services.AddControllersWithViews();
services.AddRazorPages(options =>
{
options.Conventions.AuthorizePage("/Students/StudentInfo/");
options.Conventions.AuthorizeFolder("/Private");
});
services.AddDbContext<TrainingDbContext>(options =>
{
options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection2"));
options.UseQueryTrackingBehavior(QueryTrackingBehavior.NoTracking);
});
services.AddAuthorization(options =>
{
options.FallbackPolicy = new AuthorizationPolicyBuilder()
.RequireAuthenticatedUser()
.Build();
});
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
app.UseDatabaseErrorPage();
}
else
{
app.UseExceptionHandler("/Home/Error");
app.UseHsts();
}
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();
app.UseAuthentication();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllerRoute(
name: "default",
pattern: "{controller=Home}/{action=Index}/{id?}");
endpoints.MapRazorPages();
endpoints.MapHub<ChatHub>("/chatHub");
});
RotativaConfiguration.Setup((Microsoft.AspNetCore.Hosting.IHostingEnvironment)env);
}
}
}
如下更改代码：
private readonly Microsoft.AspNetCore.Mvc.Infrastructure.IActionContextAccessor actionContextAccessor;
public HomeController(Microsoft.AspNetCore.Mvc.Infrastructure.IActionContextAccessor actionContextAccessor,IConfiguration configuration,IWebHostEnvironment env, MvcCore3_1Context context)
{
this.actionContextAccessor = actionContextAccessor;
}
Startup.cs:
public void ConfigureServices(IServiceCollection services)
{
services.AddSingleton<IActionContextAccessor, ActionContextAccessor>();
services.AddControllersWithViews();
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
app.UseHttpsRedirection();
app.UseStaticFiles();
RotativaConfiguration.Setup(env.WebRootPath, "Rotativa");
app.UseRouting();
app.UseAuthentication();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllerRoute(
name: "default",
pattern: "{controller=Home}/{action=Privacy}/{id?}");
});
}
参考：
https://stackoverflow.com/a/61864127/11398810
问题解决了。但我有点好奇。您的类名是MyController，但构造函数是StudentsController。
public class MyController : Controller
{
private readonly IWebHostEnvironment _hostEnvironment;
private readonly ActionContext _actionContext;
public StudentsController(
IWebHostEnvironment hostEnvironment,
Acti
onContext actionContext)
{
_hostEnvironment = hostEnvironment;
_actionContext = actionContext;
}