This topic has not yet been rated - Rate this topic

exceptionSwallowedOnCallFromCom MDA

.NET Framework 4.5

The exceptionSwallowedOnCallFromCOM managed debugging assistant (MDA) is activated when an exception is thrown from common language runtime (CLR) code called from COM via a method that does not have an unmanaged HRESULT return type.

Symptoms

A call to a managed component from COM returns with a value of FALSE or 0. Alternatively, if the method has a void return type, there may be no indication that an exception was thrown during the execution of the method. In this case, the exception will be silently caught and execution will return to the COM caller.

Cause

An exception was thrown, but there is no valid way to report it.

Resolution

Informational only, not necessarily indicative of a bug.

Effect on the Runtime

This MDA has no effect on the CLR. It only reports data about silently caught exceptions.

Output

Informational message containing the method name, type name, and exception message.

Configuration

<mdaConfig>
  <assistants>
    <exceptionSwallowedOnCallFromCom enable="false" />
  </assistants>
</mdaConfig>

Reference

MarshalAsAttribute

Concepts

Diagnosing Errors with Managed Debugging Assistants

Other Resources

Interop Marshaling

Interoperability

Did you find this helpful? Yes No

Not accurate

Not enough depth

Need more code examples

(1500 characters remaining)