C# winform判断自身程序是否已运行,如果已运行则激活窗体
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace WindowsFormsApp1
{
internal static class Program
{
[DllImport("user32.dll")]
public static extern void SwitchToThisWindow(IntPtr hWnd, bool fAltTab);
[STAThread]
static void Main()
{
Process currentProcess = Process.GetCurrentProcess();
Process[] processes = Process.GetProcessesByName(currentProcess.ProcessName);
if (processes.Length > 1)
{
IntPtr handle = GetOldProcess(processes, currentProcess).MainWindowHandle;
SwitchToThisWindow(handle, true);
Thread.Sleep(1000);
Environment.Exit(1);
}
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
private static Process GetOldProcess(Process[] processes, Process currentProcess)
{
foreach (Process process in processes)
{
if (process.Id != currentProcess.Id)
{
return process;
}
}
return null;
}
}
}