CODEWITHSUNDEEP
c#.netwpf
AVEbrahimi
AVEbrahimi

Reputation: 19214

process.MainWindowHandle is zero?

Why process.MainWindowHandle is zero in code below?

Process me = Process.GetCurrentProcess();
foreach (Process process in Process.GetProcessesByName(me.ProcessName))
                    {
                        if (process.Id != me.Id)
                        {
                            MessageBox.Show(string.Format("{0}", process.MainWindowHandle));
                            ShowWindow(process.MainWindowHandle, 5);
                            ShowWindow(process.MainWindowHandle,3);
                            SetForegroundWindow(process.MainWindowHandle);
                            break;
                        }
                    }

Upvotes: 2

Views: 6440

Answers (3)

David Klempfner
David Klempfner

Reputation: 9940

The Process.MainWindowHandle property uses heuristics to determine what the main window is, but this doesn't always work. Try using EnumWindows. I wrote a tutorial on how to use this.

Upvotes: 3

Ash K
Ash K

Reputation: 3731

One thing to add to already excellent answers here:

If the app you're opening has a GUI but still doesn't show up in the taskbar, it's MainWindowHandle can't be found.

For eg: If you have access to the Winform app's code, go to the properties of the form and make sure this is True in the Icon section:

Mine was set to False and I had to learn this the hard way.

Upvotes: 1

ouflak
ouflak

Reputation: 2514

That your window is hidden is a critically important detail.

From the MSDN article on the Process.MainWindowHandle Property:

A process has a main window associated with it only if the process has a graphical interface. If the associated process does not have a main window, the MainWindowHandle value is zero. The value is also zero for processes that have been hidden, that is, processes that are not visible in the taskbar.

Upvotes: 3

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