No 'Access-Control-Allow-Origin' header is present on the requested

george jegan

Access to XMLHttpRequest at 'http://localhost:8080/api/photos/%7B_id%7D' from origin 'http://localhost:4200' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

4 Replies

Know the answer? Post it — somebody with the same question will find it here.

Jignesh Kumar5y ago
Hi Jegan,

Please use this link which will help you to allo CORS on your api request,
https://www.c-sharpcorner.com/article/enabling-cors-in-asp-net-core-api-application/
https://www.infoworld.com/article/3327562/how-to-enable-cors-in-aspnet-core.html
+1
Sachin Singh5y ago
if you are getting the issue in web api 2 then follow two steps
1.Go to tools-->package Manager Console and install following package
PM> Install-Package Microsoft.AspNet.WebApi.Cors
2.Go to App_Start folder and open WebAPIConfig and add EnableCors() in the Register method.
public static class WebApiConfig
    {
        public static void Register(HttpConfiguration config)
        {


            // Web API routes
            config.MapHttpAttributeRoutes();
            config.EnableCors(); // notice here

            config.Routes.MapHttpRoute(
                name: "DefaultApi",
                routeTemplate: "api/{controller}/{id}",
                defaults: new { id = RouteParameter.Optional }
            );
        }
+2
Rijwan Ansari5y ago
Only for .NET Core Web API project, add following changes:
1. Add the following code after the services.AddMvc() line in the ConfigureServices() method of the Startup.cs file:
```
services.AddCors(allowsites=>{allowsites.AddPolicy("AllowOrigin", options => options.AllowAnyOrigin());             }); 
```
1. Add the following code after app.UseMvc() line in the Configure() method of the Startup.cs file:
```
app.UseCors(options => options.AllowAnyOrigin()); 
```
1. Open the controller which you want to access outside the domain and add this following attribute at the controller level:
```
[EnableCors("AllowOrigin")]
```
+2
Kiran Mohanty5y ago
You should enable CORs while accessing cross domain API.

In .net Core
public void ConfigureServices(IServiceCollection services)  {
   services.AddCors(options =>
   {
     options.AddPolicy("Policy11",
      builder => builder.WithOrigins("http://hello.com"));
   });
}

public void Configure(IApplicationBuilder app)
{
   app.UseCors("AllowMyOrigin");
}
In MVC
public static void Register(HttpConfiguration config)
        {
            config.EnableCors();
        }
+2