using System.Runtime.InteropServices; 
#region API 
[DllImport("user32.dll")] 
static extern void mouse_event(MouseEventFlag flags, int dx, int dy, uint data, UIntPtr extraInfo); 
[Flags] 
enum MouseEventFlag : uint 
{ 
Move = 0x0001, 
LeftDown = 0x0002, 
LeftUp = 0x0004, 
RightDown = 0x0008, 
RightUp = 0x0010, 
MiddleDown = 0x0020, 
MiddleUp = 0x0040, 
XDown = 0x0080, 
XUp = 0x0100, 
Wheel = 0x0800, 
VirtualDesk = 0x4000, 
Absolute = 0x8000 
} 
#endregion 
//以上代码放在Class 任意处 
mouse_event(MouseEventFlag.Move, 0, 0, 0, UIntPtr.Zero) 

//执行左键按下 
mouse_event(MouseEventFlag.LeftDown, 0, 0, 0, UIntPtr.Zero); 

//执行左键松开 
mouse_event(MouseEventFlag.LeftUp, 0, 0, 0, UIntPtr.Zero); 
//完成一个单击动作 
//之后执行以上代码便可模似鼠标单击一次