我的 WCF 服务器上有一个执行回调的方法，如下所示。这工作正常，包括回调。
但是我如何从服务器启动客户端上的方法执行。即我想在下面的 C# 按钮代码部分中的代码。
目前我得到的错误是：
Object reference not set to an instance of an object.
可能我的架构在这里都错了，WCF 客户端也需要内置 WCF 服务器？
WCF 服务器上的 C# 方法
public void ChatToServer(string texttoServer) // send some text to the server
{
Logging.Write_To_Log_File("Entry", MethodBase.GetCurrentMethod().Name, "", "", "", 1);
try
{
IMyContractCallBack callback = OperationContext.Current.GetCallbackChannel<IMyContractCallBack>();
callback.ChatToClient("your message: " + texttoServer + " has been recieved");
Logging.Write_To_Log_File("Exit", MethodBase.GetCurrentMethod().Name, "", "", "", 1);
}
catch (Exception ex)
{
Logging.Write_To_Log_File("Error", MethodBase.GetCurrentMethod().Name, "", "", ex.ToString(), 2);
}
}
我想要的 WCF 服务器上的 C# 按钮代码
private void radButtonSend_Click(object sender, EventArgs e)
{
try
{
Logging.Write_To_Log_File("Entry", MethodBase.GetCurrentMethod().Name, "", "", "", 1);
IMyContractCallBack callback = OperationContext.Current.GetCallbackChannel<IMyContractCallBack>();
callback.ChatToClient(radTextBox2Send.Text);
Logging.Write_To_Log_File("Exit", MethodBase.GetCurrentMethod().Name, "", "", "", 1);
}
catch (Exception ex)
{
Logging.Write_To_Log_File("Error", MethodBase.GetCurrentMethod().Name, "", "", ex.ToString(), 2);
MessageBox.Show(ex.Message.ToString());
}
}
WCF 服务配置
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<system.serviceModel>
<behaviors>
<serviceBehaviors>
<behavior name="Throttled">
<serviceMetadata httpGetEnabled="False" />
<serviceDebug includeExceptionDetailInFaults="False" />
<serviceThrottling maxConcurrentCalls="100000" maxConcurrentInstances="100000" maxConcurrentSessions="100000" />
</behavior>
</serviceBehaviors>
</behaviors>
<services>
<service name="WCFService.WCFJobsLibrary" behaviorConfiguration="Throttled" >
<host>
<baseAddresses>
<add baseAddress="http://localhost:8732/Design_Time_Addresses/WCFService/WCFJobsLibrary/" />
</baseAddresses>
</host>
<endpoint name ="duplexendpoint"
address =""
binding ="wsDualHttpBinding"
contract ="WCFService.IWCFJobsLibrary"/>
<endpoint name ="MetaDataTcpEndpoint"
address="mex"
binding="mexHttpBinding"
contract="IMetadataExchange"/>
</service>
</services>
</system.serviceModel>
<system.webServer>
<modules runAllManagedModulesForAllRequests="true"/>
</system.webServer>
</configuration>
WCF 客户端配置
<configuration>
<system.serviceModel>
<bindings>
<wsDualHttpBinding>
<binding name="duplexendpoint" closeTimeout="00:01:00" openTimeout="00:01:00"
receiveTimeout="00:10:00" sendTimeout="00:01:00" bypassProxyOnLocal="false"
transactionFlow="false" hostNameComparisonMode="StrongWildcard"
maxBufferPoolSize="524288" maxReceivedMessageSize="65536" messageEncoding="Text"
textEncoding="utf-8" useDefaultWebProxy="true">
<readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
maxBytesPerRead="4096" maxNameTableCharCount="16384" />
<reliableSession ordered="true" inactivityTimeout="00:10:00" />
<security mode="Message">
<message clientCredentialType="Windows" negotiateServiceCredential="true"
algorithmSuite="Default" />
</security>
</binding>
</wsDualHttpBinding>
</bindings>
<client>
<endpoint address="http://localhost:8732/Design_Time_Addresses/WCFService/WCFJobsLibrary/"
binding="wsDualHttpBinding" bindingConfiguration="duplexendpoint"
contract="ServiceReference1.IWCFJobsLibrary" name="duplexendpoint">
</endpoint>
</client>
</system.serviceModel>
</configuration>
合同
namespace WCFService
{
[ServiceContract(CallbackContract = typeof(IMyContractCallBack))]
public interface IWCFJobsLibrary
{
[OperationContract(IsOneWay = true)]
void ChatToServer(string texttoServer); // send some text to the server
[OperationContract(IsOneWay = true)]
void NormalFunction();
[OperationContract(IsOneWay = false)]
int ChatToServerWithResult(string texttoServer); // send some text to the server and send back success indication
}
public interface IMyContractCallBack
{
[OperationContract(IsOneWay = true)]
void CallBackFunction(string str);
[OperationContract(IsOneWay = true)]
void ChatToClient(string str);
}
}