.NET CORE 3.1.5 跨域设置

1、Startup配置

#region 跨域设置
//注意：放到services.AddMvc()之前
services.AddCors(options => {
                options.AddPolicy("any",builder => {

                 #region 允许任何来源主机访问
                   builder.AllowAnyOrigin(); 
                 #endregion

                  #region 允许访问的特定域
                    //builder.WithOrigins("http://*.*.*.*")
                    //.AllowAnyMethod()
                    //.AllowAnyHeader()
                    //.AllowCredentials(); 
                   #endregion
       });
});
#endregion

//跨域设置
app.UseMiddleware<CorsMiddleware>();

 

 2、自定义Cors中间件

/// <summary>
    /// CORS 中间件 【解决跨域问题】
    /// </summary>
    public class CorsMiddleware
    {
        private readonly RequestDelegate _next;
        public CorsMiddleware(RequestDelegate next)
        {
            _next = next;
        }

        public async Task Invoke(HttpContext context)
        {
            if (!context.Response.Headers.ContainsKey("Access-Control-Allow-Origin"))
            {
                context.Response.Headers.Add("Access-Control-Allow-Origin", "*");
            }
            await _next(context);
        }
    }

 注意：startup中的Configure中，app.UseMiddleware<CorsMiddleware>()的CorsMiddleware引用为该自定义中间件。