c# - 如何在 .Net 控制台应用程序 WCF 服务中启用跨域资源共享？

Question

我有一个具有 RESTful WCF 服务的 .netframework(4.5.2) 控制台应用程序。

我在使用来自 Javascript 客户端的休息服务时遇到问题。

当我使用Postman消费rest服务时，没有问题。

当我使用 Javascript fetch 方法时，出现 CORS 错误

from origin 'http://localhost:3000' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

我尝试了以下来自谷歌的解决方案；

1- 添加 Web.config customHeaders .

Web.config adding parameter

但是，没有 web.config，我添加了以下代码 App.config

<httpProtocol>
<customHeaders>
    <add name="Access-Control-Allow-Origin" value="*"/>
    <add name="Access-Control-Allow-Headers" value="Content-Type, Accept" />
    <add name="Access-Control-Allow-Methods" value="POST,GET,OPTIONS" />
    <add name="Access-Control-Max-Age" value="1728000" />
</customHeaders>

2- Global.asax

Global.asax solution for a web project

由于之前提到的原因，没有 Global.asax。
我不能尝试这个。

3- WCF 生成器

我在构建 wcf 服务时允许此 CrossDomain 控制。这也行不通。

 var binding = new WebHttpBinding(WebHttpSecurityMode.None);
 binding.CrossDomainScriptAccessEnabled = true;

感谢您的建议。

编辑

我还在 github 上创建了一个测试应用程序。您可以在那里看到 Postman 请求到达服务方法，但 javascript 请求没有。它给出了以下错误。

https://github.com/mmustafau/StackoverServiceTestnet

...已被 CORS 策略阻止:对预检请求的响应未通过访问控制检查:它没有 HTTP ok 状态。

我的 javascript 请求如下。

 let receiptJson =   {
        "Email": "asdas@asdas.com",
        "Name": "asdasd",
        "Password": "asdasd"
    }

  const requestOptions = {
        method: 'POST',
        headers:{ 'Content-Type': 'application/json',
             },
        body: JSON.stringify (receiptJson)

    };

return  fetch("http://localhost:8070/ServiceModelSamples/service/user", requestOptions)
        .then(handleResponse)
        .then(receiptJson => {


            return receiptJson;
        });

Answer 1

WCF中有两种解决跨域问题的方法。首先是在WCF项目中添加全局配置文件。项目部署到IIS后，IIS会读取添加的全局配置文件来解决跨域问题，就像web项目一样。

 protected void Application_BeginRequest(object sender, EventArgs e)
        {
            HttpContext.Current.Response.AddHeader("Access-Control-Allow-Origin", "*");

            if (HttpContext.Current.Request.HttpMethod == "OPTIONS")

            {
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Methods", "*");

                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Headers", "*");

                HttpContext.Current.Response.End();
            }

        }

修改全局配置文件，解决跨域问题。
第二种方式是让WCF支持jsonp。我们可以在配置文件中启用JSONP。

<binding name="bind1" crossDomainScriptAccessEnabled="true">
</binding>

更新
您可以实现 idispatchmessageinspector 以在服务响应之前添加响应 header 。

 public class ServerMessageLogger : IDispatchMessageInspector
    {
        public object AfterReceiveRequest(ref Message request, IClientChannel channel, InstanceContext instanceContext)
        {
           return null;
        }

        public void BeforeSendReply(ref Message reply, object correlationState)
        {
            WebOperationContext ctx = WebOperationContext.Current;
            ctx.OutgoingResponse.Headers.Add("Access-Control-Allow-Origin", "*");
        }
    }

有关 IDispatchMessageInspector 的更多信息，请引用以下链接:
https://docs.microsoft.com/en-us/dotnet/api/system.servicemodel.dispatcher.idispatchmessageinspector?view=netframework-4.8
代码

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Channels;
using System.ServiceModel.Description;
using System.ServiceModel.Dispatcher;
using System.ServiceModel.Web;
using System.Text;
using System.Threading.Tasks;
using System.Web;
using System.Xml;

namespace Demo_rest_ConsoleApp
{
    public class ServerMessageLogger : IDispatchMessageInspector
    {
        public object AfterReceiveRequest(ref Message request, IClientChannel channel, InstanceContext instanceContext)
        {
         
            return null;
        }

        public void BeforeSendReply(ref Message reply, object correlationState)
        {

            WebOperationContext ctx = WebOperationContext.Current;
            ctx.OutgoingResponse.Headers.Add("Access-Control-Allow-Origin", "*");
        }
    }
    public class ClientMessageLogger : IClientMessageInspector
    {
        public void AfterReceiveReply(ref Message reply, object correlationState)
        {
    
        }

        public object BeforeSendRequest(ref Message request, IClientChannel channel)
        {
            
            return null;
        }
    }
    [AttributeUsage(AttributeTargets.Interface | AttributeTargets.Class, AllowMultiple = false)]
    public class CustContractBehaviorAttribute : Attribute, IContractBehavior, IContractBehaviorAttribute
    {
        public Type TargetContract => throw new NotImplementedException();

        public void AddBindingParameters(ContractDescription contractDescription, ServiceEndpoint endpoint, BindingParameterCollection bindingParameters)
        {
            return;
        }

        public void ApplyClientBehavior(ContractDescription contractDescription, ServiceEndpoint endpoint, ClientRuntime clientRuntime)
        {
            clientRuntime.ClientMessageInspectors.Add(new ClientMessageLogger());
        }

        public void ApplyDispatchBehavior(ContractDescription contractDescription, ServiceEndpoint endpoint, DispatchRuntime dispatchRuntime)
        {
            dispatchRuntime.MessageInspectors.Add(new ServerMessageLogger());
        }

        public void Validate(ContractDescription contractDescription, ServiceEndpoint endpoint)
        {
            return;
        }
    }
}

向服务添加行为

这是我的项目目录

App.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <startup>
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.7.2" />
    </startup>

    <system.serviceModel>
        <services>

            <service name="Demo_rest_ConsoleApp.Service1" behaviorConfiguration="ServiceBehavior">
                <host>
                    <baseAddresses>
                        <add baseAddress="http://localhost:8012/ServiceModelSamples/service"/>
                    </baseAddresses>
                </host>

                <endpoint address=""
                          binding="webHttpBinding"
                          contract="Demo_rest_ConsoleApp.IService1"
                          behaviorConfiguration="ESEndPointBehavior" />
            </service>
        </services>


        <behaviors>
            <endpointBehaviors>
                <behavior name="ESEndPointBehavior">
                    <webHttp helpEnabled="true"/>
                </behavior>
            </endpointBehaviors>

            <serviceBehaviors>
                <behavior name="ServiceBehavior">
                    <serviceMetadata httpGetEnabled="true"/>
                </behavior>
            </serviceBehaviors>

        </behaviors>
    
    </system.serviceModel>
    
</configuration>

dao.cs

using System;
using System.Data;
using System.Data.SqlClient;
namespace Demo_rest_ConsoleApp
{
    public class Sqlservercon
    {
        public UserData Selectuser(string username)
        {
            UserData user = new UserData();
            user.Email = "Test";
            user.Name = "Test";
            user.Password = "Test";
            return user;
        }
        public UserData Adduser(UserData userdata)
        {
            UserData user = new UserData();
            user.Email = "Test";
            user.Name = "Test";
            user.Password = "Test";
            return user;
        }
        public UserData Updateuser(UserData userdata)
        {
            UserData user = new UserData();
            user.Email = "Test";
            user.Name = "Test";
            user.Password = "Test";
            return user;
        }
        public UserData Deleteuser(UserData userdata)
        {
            UserData user = new UserData();
            user.Email = "Test";
            user.Name = "Test";
            user.Password = "Test";
            return user;
        }
    }
}

IService1.cs

using System.Runtime.CompilerServices;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Web;
using static Demo_rest_ConsoleApp.soap;

namespace Demo_rest_ConsoleApp
{
    [ServiceContract]
    [CustContractBehavior]
    public interface IService1
    {
        [OperationContract]
        [WebInvoke(Method = "GET", UriTemplate = "user/{name}",ResponseFormat = WebMessageFormat.Json)]
        Result GetUserData(string name);

        [OperationContract]
        [WebInvoke(Method = "POST", UriTemplate = "user", RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json)]
        Result PostUserData(UserData user);
        [OperationContract]
        [WebInvoke(Method = "PUT", UriTemplate = "user", RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json)]
        Result PutUserData(UserData user);
        [OperationContract]
        [WebInvoke(Method = "DELETE", UriTemplate = "user", RequestFormat = WebMessageFormat.Json, ResponseFormat = WebMessageFormat.Json)]
        Result DeleteUserData(UserData user);
    }
    [DataContract(Name = "user")]
    public class UserData
    {
        [DataMember(Name = "Name")]
        public string Name { get; set; }
        [DataMember(Name = "Password")]
        public string Password { get; set; }
        [DataMember(Name = "Email")]
        public string Email { get; set; }
    }
    [DataContract(Name = "Result")]
    public class Result
    {
        [DataMember(Name = "Stu")]
        public string Stu { get; set; }
        [DataMember(Name = "Code")]
        public int Code { get; set; }
        [DataMember(Name = "UserData")]
        public UserData userData { get; set; }
    }
}

程序.cs

using System;
using System.ServiceModel;
using System.ServiceModel.Description;
namespace Demo_rest_ConsoleApp
{
    class Program
    {
        
        static void Main(string[] args)
        {
           
            ServiceHost selfHost = new ServiceHost(typeof(Service1));
            selfHost.Open();
            Console.WriteLine("Service Open");
            Console.ReadKey();
            selfHost.Close();
        }
    }
}

Service1.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.Serialization;
using System.ServiceModel;
using System.ServiceModel.Activation;
using System.ServiceModel.Web;
using System.Text;
namespace Demo_rest_ConsoleApp
{
 
    public class Service1 : IService1
    {
        Sqlservercon sqlservercon = new Sqlservercon();

        public Result PostUserData(UserData user)
        {
            Result result = new Result();
            if (GetUserData(user.Name).Code == 400)
            {
                sqlservercon.Adduser(user);
                result.Code = 200;
                result.Stu = user.Name + "Success";
                result.userData = user;
                return result;
            }
            else
            {
                result.Code = 400;
                result.Stu = user.Name + "fail";
                return result;
            }
        }

        public Result DeleteUserData(UserData user)
        {
            Result result = new Result();
            if (GetUserData(user.Name).Code == 400)
            {
                result.Code = 400;
                result.Stu = user.Name + "fail";
                return result;
            }
            else
            {
                sqlservercon.Deleteuser(user);
                result.Code = 200;
                result.Stu = user.Name + "Success！";
                result.userData = user;
                return result;
            }
        }
        static List<Result> results = new List<Result>();
        public Result GetUserData(string name)
        {
            UserData userData = sqlservercon.Selectuser(name);
            Result result = new Result();
            if (userData.Name != "")
            {
                result.userData = userData;
                result.Code = 200;
                result.Stu = "Success";
                results.Add(result);
                Console.WriteLine(results.Count);
                return result;
            }
            else
            {
                result.Code = 400;
                result.Stu = "fail";
                return result;
            }


        }
        public Result PutUserData(UserData user)
        {
            Result result = new Result();
            if (GetUserData(user.Name).Code == 400)
            {
                result.Code = 400;
                result.Stu = user.Name + "fail";
                return result;
            }
            else
            {
                sqlservercon.Updateuser(user);
                result.Code = 200;
                result.Stu = user.Name + "Success";
                result.userData = user;
                return result;
            }
        }
    }
}

soap.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.ServiceModel;
using System.ServiceModel.Channels;
using System.ServiceModel.Description;
using System.ServiceModel.Dispatcher;
using System.ServiceModel.Web;
using System.Text;
using System.Threading.Tasks;

namespace Demo_rest_ConsoleApp
{
    class soap
    {

        public class ServerMessageLogger : IDispatchMessageInspector
        {
            public object AfterReceiveRequest(ref Message request, IClientChannel channel, InstanceContext instanceContext)
            {
                return null;
            }

            public void BeforeSendReply(ref Message reply, object correlationState)
            {

               WebOperationContext ctx = WebOperationContext.Current;
              ctx.OutgoingResponse.Headers.Add("Access-Control-Allow-Origin", "*");
            }
        }
        public class ClientMessageLogger : IClientMessageInspector
        {
            public void AfterReceiveReply(ref Message reply, object correlationState)
            {
            }

            public object BeforeSendRequest(ref Message request, IClientChannel channel)
            {
                return null;
            }
        }
        [AttributeUsage(AttributeTargets.Interface | AttributeTargets.Class, AllowMultiple = false)]
        public class CustContractBehaviorAttribute : Attribute, IContractBehavior, IContractBehaviorAttribute
        {
            public Type TargetContract => throw new NotImplementedException();

            public void AddBindingParameters(ContractDescription contractDescription, ServiceEndpoint endpoint, BindingParameterCollection bindingParameters)
            {
                return;
            }

            public void ApplyClientBehavior(ContractDescription contractDescription, ServiceEndpoint endpoint, ClientRuntime clientRuntime)
            {
                clientRuntime.ClientMessageInspectors.Add(new ClientMessageLogger());
            }

            public void ApplyDispatchBehavior(ContractDescription contractDescription, ServiceEndpoint endpoint, DispatchRuntime dispatchRuntime)
            {
                dispatchRuntime.MessageInspectors.Add(new ServerMessageLogger());
            }

            public void Validate(ContractDescription contractDescription, ServiceEndpoint endpoint)
            {
                return;
            }
        }
    }
}

Ajax

<!DOCTYPE html>
<html>
<head>
    <meta charset="utf-8">
    <title>Ajax</title>
    <script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js">
    </script>
    <script>
$(document).ready(function(){
    $("button").click(function () {
        var da = { "Email":"123","Name":"dg3","Password":"dasd" };
        $.ajax({
            type: "get",
            dataType: "json",
         //   contentType: "application/json;charset=utf-16",
        //    data: JSON.stringify(da),
            url: "http://localhost:8070/ServiceModelSamples/service/user/dd", success: function (result) {

               
                
                    document.write( "name:" + (result.UserData).Name + " " + "password:" + (result.UserData).Password + " " + "email:" + (result.UserData).Email);
                
              
        }});
    });
});
    </script>
</head>
<body>


    <button>Call WCF Rest Service</button>

</body>
</html>