winform

#region 标题移动
Point pt;
private void PLTitle_MouseDown(object sender, MouseEventArgs e)
{
pt = Cursor.Position;
}

private void PLTitle_MouseMove(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
int px = Cursor.Position.X - pt.X;
int py = Cursor.Position.Y - pt.Y;
this.Location = new Point(this.Location.X + px, this.Location.Y + py);

pt = Cursor.Position;
}
}
#endregion

static class Program
{
/// <summary>
/// 应用程序的主入口点。
/// </summary>
[ STAThread]
static void Main()
{
//0106add 一次打开一个应用程序
Process instance = RunningInstance();
if (instance != null)
{
if (instance.MainWindowHandle.ToInt32() == 0) //是否托盘化
{
MessageBox.Show( "程序已打开并托盘化");
return;
}
//1.2 已经有一个实例在运行
HandleRunningInstance(instance);
return;
}

Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault( false);
Application.Run( new Form1());

}




#region 确保程序只运行一个实例
private static Process RunningInstance()
{
Process current = Process.GetCurrentProcess();
Process[] processes = Process.GetProcessesByName(current.ProcessName);
//遍历与当前进程名称相同的进程列表
foreach (Process process in processes)
{
//如果实例已经存在则忽略当前进程
if (process.Id != current.Id)
{
//保证要打开的进程同已经存在的进程来自同一文件路径
if (Assembly.GetExecutingAssembly().Location.Replace("/", "\\") == current.MainModule.FileName)
{
//返回已经存在的进程
return process;
}
}
}
return null;
}
//3.已经有了就把它激活，并将其窗口放置最前端
private static void HandleRunningInstance(Process instance)
{
ShowWindowAsync(instance.MainWindowHandle, 1); //调用api函数，正常显示窗口
SetForegroundWindow(instance.MainWindowHandle); //将窗口放置最前端
}
[ 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