WinForms：光標進入/離開窗體或其控件時檢測

Question

我需要一種檢測光標何時進入或離開窗體的方法。當控件填充表單時，Form.MouseEnter/MouseLeave不起作用，因此我還必須訂閱控件的MouseEnter事件（例如表單上的面板）。任何其他跟蹤形式光標進入/退出全球？

Answer 1

你可以用win32的做到像這樣的回答： How to detect if the mouse is inside the whole form and child controls in C#?

或者你可以只鉤出來頂層控件形式的OnLoad：

 foreach (Control control in this.Controls) 
      control.MouseEnter += new EventHandler(form_MouseEnter); 

Answer 2

你可以試試這個：

private void Form3_Load(object sender, EventArgs e) 
{ 
    MouseDetector m = new MouseDetector(); 
    m.MouseMove += new MouseDetector.MouseMoveDLG(m_MouseMove); 
} 

void m_MouseMove(object sender, Point p) 
{ 
    Point pt = this.PointToClient(p); 
    this.Text = (this.ClientSize.Width >= pt.X && 
       this.ClientSize.Height >= pt.Y && 
       pt.X > 0 && pt.Y > 0)?"In":"Out";  
} 

的MouseDetector類：

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 
using System.Runtime.InteropServices; 
using System.Windows.Forms; 
using System.Drawing; 

class MouseDetector 
{ 
    #region APIs 

    [DllImport("gdi32")] 
    public static extern uint GetPixel(IntPtr hDC, int XPos, int YPos); 

    [DllImport("user32.dll", CharSet = CharSet.Auto)] 
    public static extern bool GetCursorPos(out POINT pt); 

    [DllImport("User32.dll", CharSet = CharSet.Auto)] 
    public static extern IntPtr GetWindowDC(IntPtr hWnd); 

    #endregion 

    Timer tm = new Timer() {Interval = 10}; 
    public delegate void MouseMoveDLG(object sender, Point p); 
    public event MouseMoveDLG MouseMove; 
    public MouseDetector() 
    {     
    tm.Tick += new EventHandler(tm_Tick); tm.Start(); 
    } 

    void tm_Tick(object sender, EventArgs e) 
    { 
    POINT p; 
    GetCursorPos(out p); 
    if (MouseMove != null) MouseMove(this, new Point(p.X,p.Y)); 
    } 

    [StructLayout(LayoutKind.Sequential)] 
    public struct POINT 
    { 
    public int X; 
    public int Y; 
    public POINT(int x, int y) 
    { 
     X = x; 
     Y = y; 
    } 
    } 
}