public static List <IntPtr> GetWindowHandle(int processId)
{
ProcessWindowHandleObtainer obtainer = new ProcessWindowHandleObtainer();
obtainer._processId = (uint)processId;
Win32.EnumWindowsProc proc = new Win32.EnumWindowsProc(obtainer.EnumWindowsCallback);
Win32.EnumWindows(proc, 0);
return(obtainer._windowHandles);
}
public static bool IsThereAnInstanceOfThisProgramAlreadyRunning(Action actionOnThePreviousInstance = Action.None, string windowName = null)
{
var thisProcess = Process.GetCurrentProcess();
string processName = thisProcess.ProcessName;
List <Process> processList = new List <Process>();
processList.AddRange(Process.GetProcessesByName(processName));
if (processName.EndsWith(".vshost"))
{
processName = processName.Substring(0, processName.Length - 7);
processList.AddRange(Process.GetProcessesByName(processName));
}
if (processList.Count == 1)
{
return(false); // There's just the current process.
}
if (actionOnThePreviousInstance != Action.None)
{
foreach (var process in processList)
{
if (process.Id != thisProcess.Id)
{
// Activate the previous instance.
IntPtr windowHandle = IntPtr.Zero;
List <IntPtr> windowHandles = ProcessWindowHandleObtainer.GetWindowHandle(process.Id);
foreach (IntPtr handle in windowHandles)
{
if (!string.IsNullOrEmpty(windowName))
{
StringBuilder windowText = new StringBuilder(260);
Win32.GetWindowText(handle, windowText, 260);
if (windowText.ToString() == windowName)
{
windowHandle = handle;
}
}
else
{
windowHandle = handle;
}
break;
}
if (windowHandle != IntPtr.Zero)
{
switch (actionOnThePreviousInstance)
{
case Action.Activate:
Win32.ShowWindow(windowHandle, Win32.SW.RESTORE);
Win32.SetForegroundWindow(windowHandle);
break;
case Action.Hide:
Win32.ShowWindow(windowHandle, Win32.SW.HIDE);
break;
}
}
}
}
}
return(true);
}