抛出COMException但未陷入C＃

Question

I have the following code to trigger on a button click:

        private void buttonConnect_Click(object sender, EventArgs e)
    {
        _BMDSwitcherConnectToFailure failReason = 0;
        string address = textBoxIP.Text;

        try
        {
            // Note that ConnectTo() can take several seconds to return, both for success or failure,
            // depending upon hostname resolution and network response times, so it may be best to
            // do this in a separate thread to prevent the main GUI thread blocking.
            m_switcherDiscovery.ConnectTo(address, out m_switcher, out failReason);
        }
        catch (COMException)
        {
            // An exception will be thrown if ConnectTo fails. For more information, see failReason.
            switch (failReason)
            {
                case _BMDSwitcherConnectToFailure.bmdSwitcherConnectToFailureNoResponse:
                    MessageBox.Show("No response from Switcher. Are you sure the IP is correct?", "Error");
                    break;
                case _BMDSwitcherConnectToFailure.bmdSwitcherConnectToFailureIncompatibleFirmware:
                    MessageBox.Show("Switcher has incompatible firmware", "Error");
                    break;
                default:
                    MessageBox.Show("Connection failed for unknown reason", "Error");
                    break;
            }
            return;
        }

        SwitcherConnected();
    }

I noticed that when on a different machine, the program wouldn't run. I setup VS to break on the specific error and I get this:

Exception thrown: 'System.Runtime.InteropServices.COMException'

Additional information: Error HRESULT E_FAIL has been returned from a call to a COM component.

It throws this on the following line:

_switcherDiscovery.ConnectTo(address, out m_switcher, out failReason);

I'm struggling to figure out what this exception isn't caught by the code.

Answer 1

Check in Visual Studio debug options that you have this Exception type selected:

Debug - > Exceptions

Expand the CLRE (Common Language Runtime Exceptions)

Then expand - System.Runtime.InteropServices