Winform consuming WCF service hosted in a Windows service got error #405 (method not allowed e)

Question

WCF service is hosted in a Windows service. I get successful response from web browser, but I can't call it form a Winforms application. I always get an error #405. Any ideas?

I have enabled "CORS" in my WCF service, I turned on all the required components from "Windows feature on and off ".

This is my client's app.config file

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <system.serviceModel>
        <diagnostics>
            <messageLogging logEntireMessage="true" logMessagesAtServiceLevel="true"
                            logMessagesAtTransportLevel="true" />
            <endToEndTracing propagateActivity="true" activityTracing="true"
                             messageFlowTracing="true" />
        </diagnostics>
        <behaviors>
            <endpointBehaviors>
                <behavior name="AjaxBehavior">
                    <webHttp defaultOutgoingResponseFormat="Json"/>
                </behavior>
            </endpointBehaviors>
        </behaviors>
        <client>
            <endpoint 
                address="http://localhost:8080/ "
                behaviorConfiguration="AjaxBehavior"
                binding="webHttpBinding"
                contract="IScaleService" />
        </client>
    </system.serviceModel>
</configuration>

This is my WCF service config file:

<configuration>
    <appSettings>
        <add key="port" value="COM3"/>
    </appSettings>
    <system.serviceModel>
        <behaviors>
            <endpointBehaviors>
                <behavior name="AjaxBehavior">
                    <webHttp defaultOutgoingResponseFormat="Json"/>
                </behavior>
            </endpointBehaviors>
            <serviceBehaviors>
                <behavior name="WindowsScaleTypeBehaviors" >
                    <serviceMetadata httpGetEnabled="true" httpGetUrl="http://localhost:8080/mex"/>
                </behavior>
            </serviceBehaviors>
        </behaviors>
        <bindings>
            <webHttpBinding>
                <binding name="webHttpBindingWithJsonP" crossDomainScriptAccessEnabled="true" />
            </webHttpBinding>
        </bindings>
        <services>
            <service name="ScaleService.Scale"  
                     behaviorConfiguration="WindowsScaleTypeBehaviors">
                <endpoint 
                    address="" 
                    behaviorConfiguration="AjaxBehavior" 
                    binding="webHttpBinding"
                    bindingConfiguration="webHttpBindingWithJsonP"
                    contract="ScaleService.IScaleService" />
                <endpoint 
                    address="mex"
                    binding="mexHttpBinding"
                    contract="IMetadataExchange"/>
                <host>
                    <baseAddresses>
                        <add baseAddress="http://localhost:8080/" />
                    </baseAddresses>
                </host>
            </service>
        </services>
    </system.serviceModel>
</configuration>

Answer 1

Finally, I found what's wrong with my app. The auto generated proxy class did not add webget attribute to the operation.

[System.ServiceModel.Web.WebGet]
 [System.ServiceModel.OperationContractAttribute(Action="http://tempuri.org/IScaleService/Get_Available_Ports", ReplyAction="http://tempuri.org/IScaleService/Get_Available_PortsResponse")]
 ScaleService.Lib.Ports[] Get_Available_Ports();