using System;
using System.Diagnostics;
using System.Threading;
using System.Windows.Forms;
using System.Runtime.InteropServices;
namespace ReportViewer
{
/// Summary description for ProcessUtils.
public static class ProcessUtils
{
private static Mutex mutex = null;
/// Determine if the current process is already running
public static bool ThisProcessIsAlreadyRunning()
{
// Only want to call this method once, at startup.
Debug.Assert(mutex == null);
// createdNew needs to be false in .Net 2.0, otherwise, if another instance of
// this program is running, the Mutex constructor will block, and then throw
// an exception if the other instance is shut down.
bool createdNew = false;
mutex = new Mutex(false, Application.ProductName, out createdNew);
Debug.Assert(mutex != null);
return !createdNew;
}
[DllImport("user32.dll", SetLastError = true)]
static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool SetForegroundWindow(IntPtr hWnd);
[DllImport("user32.dll")]
static extern bool IsIconic(IntPtr hWnd);
[DllImport("user32.dll")]
static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
const int SW_RESTORE = 9;
[DllImport("user32.dll")]
static extern IntPtr GetLastActivePopup(IntPtr hWnd);
[DllImport("user32.dll")]
static extern bool IsWindowEnabled(IntPtr hWnd);
/// Set focus to the previous instance of the specified program.
public static void SetFocusToPreviousInstance(string windowCaption)
{
// Look for previous instance of this program.
IntPtr hWnd = FindWindow(null, windowCaption);
// If a previous instance of this program was found...
if (hWnd != null)
{
// Is it displaying a popup window?
IntPtr hPopupWnd = GetLastActivePopup(hWnd);
// If so, set focus to the popup window. Otherwise set focus
// to the program's main window.
if (hPopupWnd != null && IsWindowEnabled(hPopupWnd))
{
hWnd = hPopupWnd;
}
SetForegroundWindow(hWnd);
// If program is minimized, restore it.
if (IsIconic(hWnd))
{
ShowWindow(hWnd, SW_RESTORE);
}
}
}
}
}
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