using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace NetTools
{
static class Program
    {

        [DllImport("user32.dll")]
private static extern bool FlashWindow(IntPtr hWnd, bool bInvert);

        [DllImport("user32.dll")]
private static extern bool FlashWindowEx(int pfwi);

/// <summary>
/// 应用程序的主入口点。
/// </summary>
        [STAThread]
static void Main()
        {
bool runone;
            System.Threading.Mutex run = new System.Threading.Mutex(true, "single_test", out runone);
if (runone)
            {
                run.ReleaseMutex();
                Application.EnableVisualStyles();
                Application.SetCompatibleTextRenderingDefault(false);
                FrmRemote frm = new FrmRemote();
int hdc = frm.Handle.ToInt32(); // write to ...
                Application.Run(frm);
                IntPtr a = new IntPtr(hdc);
            }
else
            {
MessageBox.Show("已经运行了一个实例了。");
                //IntPtr hdc = new IntPtr(1312810); // read from...
                //bool flash = FlashWindow(hdc, true);
            }

        }
    }
}

public static System.Diagnostics.Process RunningInstance() 
{ 
System.Diagnostics.Process current = System.Diagnostics.Process.GetCurrentProcess(); 
System.Diagnostics.Process[] processes = System.Diagnostics.Process.GetProcesses(); 
foreach (System.Diagnostics.Process process in processes) //查找相同名称的进程 
{ 
if (process.Id != current.Id) //忽略当前进程 
{ //确认相同进程的程序运行位置是否一样. 
 if (System.Reflection.Assembly.GetExecutingAssembly().Location.Replace("/", @"\") == current.MainModule.FileName) 
  { //Return the other process instance. 
   return process; 
  } 
 } 
} //No other instance was found, return null. 
 return null; 
} 

static void Main() 
{ 
if(RunningInstance()==null) 
{ 
 Application.EnableVisualStyles(); 
 Application.SetCompatibleTextRenderingDefault(false); 
 Application.Run(new Form1()); 
} 
else 
{ 
 MessageBox.Show("已经运行了一个实例了。"); 
} 
} 

[System.Runtime.InteropServices.DllImport("kernel32.dll")] 
public static extern UInt32 GlobalAddAtom(String lpString); //添加原子 
[System.Runtime.InteropServices.DllImport("kernel32.dll")] 
public static extern UInt32 GlobalFindAtom(String lpString); //查找原子 
[System.Runtime.InteropServices.DllImport("kernel32.dll")] 
public static extern UInt32 GlobalDeleteAtom(UInt32 nAtom); //删除原子

static void Main() 
{ 
if (GlobalFindAtom("jiaao_test") == 77856768) //没找到原子"jiaao_test" 
{ 
 GlobalAddAtom("jiaao_test"); //添加原子"jiaao_test" 
 Application.EnableVisualStyles(); 
 Application.SetCompatibleTextRenderingDefault(false); 
 Application.Run(new Form1()); 
} 
else 
{ 
 MessageBox.Show("已经运行了一个实例了。"); 
} 
}