static class Program
{
//给这个程序主窗体起个名字
private static string strProcessName = "Form1";
private static string strAppName = "WindowsFormsApplication1";
static int hWnd = 0;
//随便个数字,用来做判断
const int SW_SHOW = 1;
//指定是那个DLL,或者进程
[DllImport("user32.dll", EntryPoint = "ShowWindow")]
public static extern int ShowWindow(int hwnd, int nCmdShow);
[DllImport("user32")]
public static extern int GetWindowText(int hWnd, StringBuilder lpString, int nMaxCount);
[DllImport("user32")]
public static extern int EnumWindows(CallBack x, int y);
public delegate bool CallBack(int hWnd, int lParam);
/// <summary>
/// 应用程序的主入口点。
/// </summary>
[STAThread]
static void Main()
{
//进程数组
Process[] ps = Process.GetProcessesByName(strAppName);
//声明个委托
CallBack myCallBack = new CallBack(FineAppWindow);
EnumWindows(myCallBack, 0);
if (ps.Length > 1)
{//如果进程里面有这个
ShowWindow(hWnd, SW_SHOW);
return;
}
else
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}
}
public static bool FineAppWindow(int hwnd, int lParam)
{
StringBuilder sb = new StringBuilder(200);
int n = GetWindowText(hwnd, sb, 200);
if (sb.ToString() == strProcessName)
{
hWnd = hwnd;
}
return true;
}
}
调用的是系统的一个类库,代码也是在网上找到 就直接贴上去了 收藏,希望作者见了勿怪!非原创