Angular 6 与 Asp.net Core 2.1 不存在“Access-Control-Allow-Origin”标头

Posted 2023-03-04

【中文标题】Angular 6 与 Asp.net Core 2.1 不存在“Access-Control-Allow-Origin”标头

【英文标题】：No 'Access-Control-Allow-Origin' header is present Angular 6 with Asp.net Core 2.1

【发布时间】：2019-01-12 10:15:46

【问题描述】：

不断收到 No 'Access-Control-Allow-Origin' header is present 使用 asp.net core 2.1 的角度 6 中的错误。

我知道这是 cors 错误。我已经在服务器端添加了策略，但仍然是同样的问题。

startup.cs

services.AddCors(o => o.AddPolicy("CorsPolicy", builder =>
            
                builder.AllowAnyOrigin()
                       .AllowAnyMethod()
                       .AllowAnyHeader()
                       .AllowCredentials().WithOrigins("http://localhost:4200");
            ));



app.UseCors("CorsPolicy");

app.UseMvc();

控制器代码

[HttpPost, AllowAnonymous]
        public GenericResponseObject<JwtTokenViewModel> UserAuthentication([FromBody] UserViewModel user)
        

            GenericResponseObject<JwtTokenViewModel> genericResponseObject = new GenericResponseObject<JwtTokenViewModel>();
            genericResponseObject.IsSuccess = false;
            genericResponseObject.Message = ConstaintStingValue.TagConnectionFailed;
            if (ModelState.IsValid)
            
                try
                
                    UserViewModel userViewModel = _adminUOW.AdminAuthentication(user);
                    if (userViewModel != null)
                    
                        string token = new CommonController(tokenOptions).GetToken(userViewModel, DateTime.UtcNow.AddDays(2));
                        genericResponseObject.Data = new JwtTokenViewModel
                        
                            UserName = userViewModel.UserName,
                            UserId = userViewModel.UserId,
                            authenticated = true,
                            entityId = 1,
                            tokenExpires = DateTime.UtcNow.AddHours(2),
                            token = token,
                            SelectedRole = userViewModel.SelectedRole
                        ;
                    
                    else
                    
                        genericResponseObject.SuccessMessage = ConstaintStingValue.Tag_No_Profile_key;
                    

                    genericResponseObject.IsSuccess = true;
                    genericResponseObject.Message = ConstaintStingValue.TagConnectionSuccess;
                
                catch (Exception exception)
                
                    genericResponseObject.IsSuccess = true;
                    genericResponseObject.SuccessMessage = exception.Message;
                    genericResponseObject.ErrorCode = exception.HResult;
                    genericResponseObject.ExceptionErrorMessage = exception.StackTrace;
                    WriteExceptionToFile.WriteExceptionToFileInLogger(_hostingEnvironment, exception);
                
            

            return genericResponseObject;

        

打字稿代码

login(modelValue: UserViewModel, isValid: boolean) 
    if (isValid)    this.genericHttpClientService.GenericHttpPostAndResponse<GenericResponseObject<JwtTokenViewModel>, UserViewModel>(this._userViewModel, this.commonConstantValue.adminLoginUrl).subscribe(item => 
                if (item.data!= null && item.data.authenticated) 
                  this.router.navigate(['admin-portal']);
                else
                  this.genericViewModel.successMessage = item.successMessage;
                
                this.progressBarDisplay = false;
            ,
            err => 
                console.log(err);
                this.progressBarDisplay = false;
            );

    

HttpCLient

public GenericHttpPostAndResponse<T,TE>(postViewModel: TE, destinationUrl: string): Observable<T> 
    const headers = new HttpHeaders().set('Content-Type', 'application/json; charset=utf-8');
    return this.httpClientModule.post<T>(environment.baseUrl + destinationUrl, postViewModel,  headers );

Getting Error " No 'Access-Control-Allow-Origin' header is present on the requested resource." in ionic2

How to enable CORS in ASP.net Core WebAPI

https://docs.microsoft.com/en-us/aspnet/core/security/cors?view=aspnetcore-2.1

【问题讨论】：

你能分享你的api代码吗？

添加控制器代码.....

你为 5001 端口设置 HTTPS 了吗？

对于令牌请求，不需要来自正文。此外，您应该提供内容类型：application/x-www-form-urlencoded

注意AllowAnyOrigin()会清空origins列表，然后将*添加到origins，后面的WithOrigins会添加"http://localhost:4200"到origins列表。所以，WithOrigins 在AllowAnyOrigin 之后是不必要的，可能是你的问题的原因。

【参考方案1】：

很难说真正的问题是什么。我对 CORS 的经验是，它在实践中比人们想象的要难。我有一个类似的问题，这是由于我的网站需要 Windows 身份验证。结果是预检 CORS 请求需要匿名身份验证。我看到您的控制器具有 AllowAnonymous 属性，但是，如果它托管在 IIS 中，那么该站点也需要具有匿名身份验证。