如何处理AccessViolationException

我正在从.net应用程序中使用COM对象（MODI）。我正在调用的方法将引发System.AccessViolationException，它会被Visual Studio拦截。奇怪的是，我将调用包裹在一个try捕获中，该捕获具有用于AccessViolationException，COMException和其他所有内容的处理程序，但是当Visual Studio（2010）拦截AccessViolationException时，调试器会中断方法调用（doc.OCR），如果我单步执行，它将继续到下一行而不是进入catch块。此外，如果我在Visual Studio之外运行此程序，则应用程序将崩溃。如何处理COM对象中引发的异常？

MODI.Document doc = new MODI.Document();
try
{
    doc.Create(sFileName);
    try
    {
        doc.OCR(MODI.MiLANGUAGES.miLANG_ENGLISH, false, false);
        sText = doc.Images[0].Layout.Text;
    }
    catch (System.AccessViolationException ex)
    {
        //MODI seems to get access violations for some reason, but is still able to return the OCR text.
        sText = doc.Images[0].Layout.Text;
    }
    catch (System.Runtime.InteropServices.COMException ex)
    {
        //if no text exists, the engine throws an exception.
        sText = "";
    }
    catch
    {
        sText = "";
    }

    if (sText != null)
    {
        sText = sText.Trim();
    }
}
finally
{
    doc.Close(false);

    //Cleanup routine, this is how we are able to delete files used by MODI.
    System.Runtime.InteropServices.Marshal.FinalReleaseComObject(doc);
    doc = null;
    GC.WaitForPendingFinalizers();
    GC.Collect();
    GC.WaitForPendingFinalizers();

}