如何在Wcf服务上引发异常并在客户端上捕获它？

Question

Service Demo Code:

  public class Login : UserNamePasswordValidator
    {
        public override void Validate(string userName, string password)
        {
            if (new ProjectContext().Users.Count(x => x.Username == userName && x.Password == password) == 0)
            {
                throw new FaultException("Invalid login");
            }
        }  
    }

Client Code Demo:

internal bool LoginOnWcf(string address, string password) 
        {
            try
            {
                service.ClientCredentials.ServiceCertificate.Authentication.CertificateValidationMode = System.ServiceModel.Security.X509CertificateValidationMode.None;
                service.ClientCredentials.UserName.UserName = address;
                service.ClientCredentials.UserName.Password = password;
                user = service.GetUserById(address);
                return true;
            }
            catch (FaultException ex)
            {
                MessageBox.Show(ex.Message);
                return false;
            }
        }

Web.config Demo:

<behaviors>
      <serviceBehaviors>
        <behavior name="defaultProfile">
          <serviceMetadata httpGetEnabled="true" httpsGetEnabled="true" />
          <serviceDebug includeExceptionDetailInFaults="true" />
          <serviceCredentials>
            <clientCertificate>
              <authentication certificateValidationMode="None" />
            </clientCertificate>
            <serviceCertificate findValue="App1" storeLocation="CurrentUser"
              storeName="My" x509FindType="FindBySubjectName" />
            <userNameAuthentication userNamePasswordValidationMode="Custom" customUserNamePasswordValidatorType="App1.App_Code.Authentication.Login, App_Code/Authentication"/>
          </serviceCredentials>
        </behavior>
        <behavior>
          <!-- To avoid disclosing metadata information, set the values below to false before deployment -->
          <serviceMetadata httpGetEnabled="true" httpsGetEnabled="true" />
          <!-- To receive exception details in faults for debugging purposes, set the value below to true.  Set to false before deployment to avoid disclosing exception information -->
          <serviceDebug includeExceptionDetailInFaults="false" />
        </behavior>
      </serviceBehaviors>
</behaviors>

When i throw FaultException , the service crashs. I would like to be able to catch the FaultException on client and keep the service working.

I hope to have explained my problem well and provided the nescessary code.

Answer 1

WCF uses Faults to throw errors across from the server to the client. You can use a FaultException to start and then create your own custom faults as needed.

So, in your example, you could simply do the following.

throw new FaultException("Invalid login")

This article provides a whole lot more detail on how to accomplish faults with WCF.