Use of Process with using block [duplicate]

Question

Possible Duplicate:
What happens if I don't close a System.Diagnostics.Process in my C# console app?

As System.Diagnostics.Process inherits from Component which implements IDisposable, should I always create a Process with a using block?

For example, this...:

using (var process = new Process())
{
    process.StartInfo.FileName = "some process.exe";
    process.Start();
    process.WaitForExit();
}

...instead of this:

var process = new Process
    { 
        StartInfo = { FileName = "some process.exe" }
    };
process.Start();
process.WaitForExit();

I ask because I've rarely seen Process appear in a using block; for example the MSDN page for Process does not use it. Having the use of the object initializer is helpful too.

If I should be using it, should I then go and 'retrofit' it to my existing codebase?

What might be the consequences if this were not done? (Assuming WaitForExit() is being called correctly in each case.)

Answer 1

If you don't or cannot use using(), you should make sure you Dispose the process variable when it is no longer needed.

If you use the process variable in a class (instead of a Program or a method), then that class should implement IDisposable and then call _process.Dispose in its Dispose(bool) method:

void Dispose(bool disposing)
{
    ...
    if (_process != null)
    {
        Dispose(_process);
    }
}

If there is no _process field but only a process variable that you use in your method, you must dispose of it inside the method:

void MyMethod()
{
    var process = ...
    ... use it here ...
    process.Dispose();
}

Answer 2

The MSDN example is contrived. The program which opens a process handle is exiting as soon as it starts the process. When that program exits, any handles it opened are closed.

If you open a process handle, you should close it. The Process.Dispose override of Component.Dispose simply calls Process.Close. The using statement simplifies this.