This example shows what a call to VSAIsSourceRegistered looks like. Refer to VsaRpcl Example to see the constant declarations and to see this code in a form you can run with minor modifications.
// Check to see whether a component is already registered.
// str_SAMPLE_SOURCE_GUID is the GUID for the component (defined in
// preceding code); substitute the GUID for your component.
static bool RpcSampleIsSourceRegistered()
{
long hr = S_FALSE;
RpcTryExcept
{
hr = VSAIsSourceRegistered(str_SAMPLE_SOURCE_GUID);
}
RpcExcept(1)
{
LastErrorCode = RpcExceptionCode();
}
RpcEndExcept;
return( S_OK == hr );
}