C# 通过Microsoft Dynamics CRM 2013在线插件使用web服务

我在连接用于MS Dynamics 2013插件的web服务时遇到问题（在沙盒模式下运行，因为它在MS托管的在线版本上，而不是内部版本上）

我面临的问题是，我似乎无法连接到我需要使用的web服务，以实现我正在尝试的目标

我最初在app.config中有web服务绑定，但我很快就知道app.config在本例中是不相关的（？），所以我继续在代码中创建绑定。 这是我想出的代码：

BasicHttpBinding myBinding = new BasicHttpBinding();
myBinding.Name = "BasicHttpBinding_IClientSearch";
myBinding.Security.Transport.ClientCredentialType = HttpClientCredentialType.None;
myBinding.Security.Transport.ProxyCredentialType = HttpProxyCredentialType.None;
myBinding.Security.Message.ClientCredentialType = BasicHttpMessageCredentialType.UserName;
myBinding.MaxBufferSize = 524288;
myBinding.MaxBufferPoolSize = 524288;
myBinding.MaxReceivedMessageSize = 524288;
myBinding.ReaderQuotas.MaxDepth = 32;
myBinding.ReaderQuotas.MaxArrayLength = 524288;
myBinding.ReaderQuotas.MaxStringContentLength = 524288;
myBinding.Security.Mode = BasicHttpSecurityMode.TransportWithMessageCredential;
EndpointAddress endPointAddress = new EndpointAddress(EndPointURL);
ClientSearchService.ClientSearchClient myClient = new ClientSearchService.ClientSearchClient(myBinding, endPointAddress);
myClient.Open();

当我将其部署到dynamics服务器并触发代码时，它会抛出以下错误：

The Binding with name BasicHttpBinding_IClientSearch failed validation 
because it contains a BindingElement with type System.ServiceModel.Channels.TransportSecurityBindingElement 
which is not supported in partial trust. 
Consider using BasicHttpBinding or WSHttpBinding, or hosting your application in a full-trust environment.

显然，因为它是在微软自己的托管平台上，我无法在完全信任的环境中运行它，所以我确实要求它是

basichtpsecuritymode.TransportWithMessageCredential

，因为我需要提供用户名/密码来访问该服务

这个问题有解决办法吗，或者我不能用插件完成这个任务吗