如何处理Outlook插件中的HRESULT？

private const uint HRESULT_OPERATIONABORTED = 0x80004004;

// ...

    try {
        // something that could throw COMExceptions
    } catch (System.Runtime.InteropServices.COMException e) {

        switch ((uint)e.ErrorCode) {

            case HRESULT_OPERATIONABORTED:
                break;

            default:
                break;
        }
    }

(uint)e.ErrorCode

0x80004004

0x80004004