Cannot access a disposed object exception in WCF

Question

I am using the following code to call WCF service methods

MyServiceClient proxy = new MyServiceClient();
proxy.Open();
proxy.Func1();
proxy.Close();
// Some other code
proxy.Open();
proxy.Func2();

proxy.Close();

I get the exception while calling the 'proxy.Open()' second time but sometimes the code works. I can also use the following code shown below which works fine.

MyServiceClient proxy = new MyServiceClient();

proxy.Func1();

// Some other code

proxy.Func2();

proxy.Close();

I also want to know which is the better way of calling the functions. Which approach will give better performance ?

Answer 1

Once you close a connection, you can't reuse it.

You need to make a new MyServiceClient at that point.

MyServiceClient proxy = new MyServiceClient();
proxy.Open();
proxy.Func1();
proxy.Close();

// Some other code

proxy = new MyServiceClient(); // Recreate the client here
proxy.Open();
proxy.Func2();
proxy.Close();

Answer 2

WCF is one of few instance (possibly only instance) in the .NET framework where you should NOT use the using statement with a class that implements IDisposable. This MSDN Article explains the correct pattern for using service references. This also applies to Channel instances created from ChannelFactory.