static
class
Program
{
/// <summary>
/// 應用程序的主入口點。
/// </summary>
[STAThread]
static
void
Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(
false
);
//1.這里判定是否已經有實例在運行
//只運行一個實例
Process instance = RunningInstance();
if
(instance ==
null
)
{
//1.1 沒有實例在運行
Application.Run(
new
frmMain());
}
else
{
//1.2 已經有一個實例在運行
HandleRunningInstance(instance);
}
//Application.Run(new frmMain());
}
//2.在進程中查找是否已經有實例在運行
#region 確保程序只運行一個實例
private
static
Process RunningInstance()
{
Process current = Process.GetCurrentProcess();
Process[] processes = Process.GetProcessesByName(current.ProcessName);
//遍歷與當前進程名稱相同的進程列表
foreach
(Process process
in
processes)
{
//如果實例已經存在則忽略當前進程
if
(process.Id != current.Id)
{
//保證要打開的進程同已經存在的進程來自同一文件路徑
if
(Assembly.GetExecutingAssembly().Location.Replace(
"/"
,
"\\"
) == current.MainModule.FileName)
{
//返回已經存在的進程
return
process;
}
}
}
return
null
;
}
//3.已經有了就把它激活，並將其窗口放置最前端
private
static
void
HandleRunningInstance(Process instance)
{
ShowWindowAsync(instance.MainWindowHandle, 1);
//調用api函數，正常顯示窗口
SetForegroundWindow(instance.MainWindowHandle);
//將窗口放置最前端
}
[DllImport(
"User32.dll"
)]
private
static
extern
bool
ShowWindowAsync(System.IntPtr hWnd,
int
cmdShow);
[DllImport(
"User32.dll"
)]
private
static
extern
bool
SetForegroundWindow(System.IntPtr hWnd);
#endregion
}
轉載 http://www.jb51.net/article/82124.htm