檔案 Program.cs 源代碼:
using System;
using System.Collections.Generic;
using System.Windows.Forms;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Reflection;
namespace KingwinOMS
{
static class Program
{
/// <summary>
/// 應用程式的主入口點。
/// </summary>
[STAThread]
static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
/// 隻允許程式啟動一個執行個體
/// 如果已經存在,則激活該程式的視窗,并顯示在最前端。
Process process = RuningInstance();
if (process == null)
{
Application.Run(new LoginForm());
}
else
{
/// MessageBox.Show("應用程式已經在運作中。");
HandleRunningInstance(process);
}
}
#region 該函數設定由不同線程産生的視窗的顯示狀态
/// 該函數設定由不同線程産生的視窗的顯示狀态
/// <param name="hWnd">視窗句柄</param>
/// <param name="cmdShow">指定視窗如何顯示。檢視允許值清單,請查閱ShowWlndow函數的說明部分</param>
/// <returns>如果函數原來可見,傳回值為非零;如果函數原來被隐藏,傳回值為零</returns>
[DllImport("User32.dll")]
private static extern bool ShowWindowAsync(IntPtr hWnd, int cmdShow);
/// <summary>
/// 該函數将建立指定視窗的線程設定到前台,并且激活該視窗。鍵盤輸入轉向該視窗,并為使用者改各種可視的記号。
/// 系統給建立前台視窗的線程配置設定的權限稍高于其他線程。
/// </summary>
/// <param name="hWnd">将被激活并被調入前台的視窗句柄</param>
/// <returns>如果視窗設入了前台,傳回值為非零;如果視窗未被設入前台,傳回值為零</returns>
[DllImport("User32.dll")]
private static extern bool SetForegroundWindow(IntPtr hWnd);
private const int SW_SHOWNOMAL = 1;
private static void HandleRunningInstance(Process instance)
{
ShowWindowAsync(instance.MainWindowHandle, SW_SHOWNOMAL);//顯示
SetForegroundWindow(instance.MainWindowHandle);//當到最前端
}
private static Process RuningInstance()
{
Process currentProcess = Process.GetCurrentProcess();
Process[] Processes = Process.GetProcessesByName(currentProcess.ProcessName);
foreach (Process process in Processes)
{
if (process.Id != currentProcess.Id)
{
if (Assembly.GetExecutingAssembly().Location.Replace("/", "\\") == currentProcess.MainModule.FileName)
{
return process;
}
}
}
return null;
}
#endregion
}
}