js wcf 不允许此方法

<system.webServer>
  <httpProtocol>
    <customHeaders>
      <add name="Access-Control-Allow-Origin" value="*" />
      <add name="Access-Control-Allow-Methods" value="GET, POST, PUT, DELETE, OPTIONS" />
      <add name="Access-Control-Allow-Headers" value="Content-Type, Accept" />
    </customHeaders>
  </httpProtocol>
</system.webServer>

[ServiceContract]
public interface IMyService
{
    [OperationContract]
    [WebInvoke(Method = "GET", UriTemplate = "GetData/{value}", ResponseFormat = WebMessageFormat.Json)]
    string GetData(string value);
}

public class MyService : IMyService
{
    public string GetData(string value)
    {
        return string.Format("You entered: {0}", value);
    }
}

var service = new MyService.MyService();
service.GetData("test", function(result) {
    console.log(result);
}, function(error) {
    console.log(error);
});