Handle Win32Exception thrown by Process.Start()

Question

On some computers, when I call Process.Start() to start my helper executable, I get the following exception:

System.ComponentModel.Win32Exception (0x80004005): The system cannot find the file specified
at System.Diagnostics.Process.StartWithCreateProcess(ProcessStartInfo startInfo)
at System.Diagnostics.Process.Start()

The question: when I get Win32Exception, I want to tell if this is the "file not found" exception I described or something else. How to do this reliably? Should I compare this 0x80004005 against something, or should I parse the error message?

Some explanation: the executable may get removed by for some reason (that's why file not found). This is an expected situation. If the exception was thrown with some other reason, I want to report it.

`0x80004005` is [E_FAIL](https://msdn.microsoft.com/en-us/library/windows/desktop/aa378137(v=vs.85).aspx). It's too generic to be helpful. You might have better luck with [NativeErrorCode](https://msdn.microsoft.com/en-us/library/system.componentmodel.win32exception.nativeerrorcode(v=vs.110).aspx). — GSerg, Nov 27 '16 at 14:27

Andrey Moiseev · Accepted Answer · 2021-04-30T17:37:56.740

This is how, I believe, it should be done:

public static int E_FAIL = unchecked((int)0x80004005);
public static int ERROR_FILE_NOT_FOUND = 0x2;

// When the exception is caught

catch (Win32Exception e)
{
    if(e.ErrorCode == E_FAIL && e.NativeErrorCode == ERROR_FILE_NOT_FOUND)
    {
    // This is a "File not found" exception
    }
    else
    {
    // This is something else
    }
}

E_FAIL is a HRESULT value, ERROR_FILE_NOT_FOUND is a system error code.

The error message shouldn't be used because it is culture-dependent and is actually a translation of the system error code.

Handle Win32Exception thrown by Process.Start()

1 Answers1

Linked