Get started for free
Information
Switch
Switch
The topic you requested is included in another documentation set. For convenience, it's displayed below. Choose Switch to see the topic in its original location.
This topic has not yet been rated - Rate this topic

FailedQI 

.NET Framework 3.0

The FailedQI managed debugging assistant (MDA) is activated when the runtime calls QueryInterface on a COM interface pointer on behalf of a runtime callable wrapper (RCW), and the QueryInterface call fails.

A cast on an RCW fails, or a call to COM from an RCW fails unexpectedly.

  • The call is made from the wrong context.

  • The registered proxy is failing the QueryInterface call because the call was attempted in the wrong context.

  • An OLE-owned proxy returned a failure HRESULT.

See the MSDN documentation on COM rules.

If a QueryInterface call fails, the context is switched and the QueryInterface call is attempted again to see if an incorrect context was at fault.

The managed name of the interface, the GUID of the interface, and the HRESULT of the failure.

Copy 
<mdaConfig>
  <assistants>
    <failedQI/>
  </assistants>
</mdaConfig>
Did you find this helpful?
(1500 characters remaining)

Community Additions

© 2013 Microsoft. All rights reserved.