What is the best way to tell if the mouse is above the shape or not?

Question

I figured out how to make mouse clicks throughout the form, but this method is not well suited for MouseEnterand MouseLeave. My form layout is made up of many, Panelsand TableLayoutPanelstherefore there is no comprehensive control for which I can track events, and obviously the event MouseLeavefor the button does not mean that the cursor leaves the entire form. Has anyone come up with a good way around this?

Answer 1

As someone pointed out here , you can use SetWindowsHookEx () or simply hook the MouseMove event to all the controls on the form. The latter works fine for me. The only drawback is adding or removing controls at runtime; you may need a different solution.

using System;
using System.Drawing;
using System.Windows.Forms;

namespace WindowsForms_MouseEvents
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();

            MouseMove += OnMouseMove;
            MouseLeave += OnMouseLeave;

            HookMouseMove(this.Controls);
        }

        private void HookMouseMove(Control.ControlCollection ctls)
        {
            foreach (Control ctl in ctls)
            {
                ctl.MouseMove += OnMouseMove;
                HookMouseMove(ctl.Controls);
            }
        }

        private void OnMouseMove(object sender, MouseEventArgs e)
        {
            BackColor = Color.Plum;

            Control ctl = sender as Control;
            if (ctl != null)
            {
                // Map mouse coordinate to form
                Point loc = this.PointToClient(ctl.PointToScreen(e.Location));
                Console.WriteLine("Mouse at {0},{1}", loc.X, loc.Y);
            }
        }

        private void OnMouseLeave(object sender, EventArgs e)
        {
            BackColor = Color.Gray;
        }

    }
}

Answer 2

First you need to check if the ClientRectangle contains the current mouse position. So, for example, on your MouseMove you could:

if (ClientRectangle.Contains(e.Location))
{
    bool mouseIsOverThisControl = true;
}

Answer 3

(, 50 ). Tick, , :

// Check if mouse is currently over the form
    bool temp_mof = ClientRectangle.Contains(
       Form.MousePosition.X - Location.X,
       Form.MousePosition.Y - Location.Y);

EDIT: , . timer1Tick() - Tick . . " ":)

bool m_mouse_over_form = false;
// Assume the left button is down at onset
bool m_left_button_down = true;

void timer1Tick (object sender, EventArgs e)
{
   // Check if mouse is currently over the form
   bool temp_mof = ClientRectangle.Contains(
      Form.MousePosition.X - Location.X,
      Form.MousePosition.Y - Location.Y);

   // were we already over the form before this tick?
   if (temp_mof && m_mouse_over_form)
   {
       // we need to detect the mouse down and up to avoid
       // repeated calls if the mouse button is held down for more
       // than our Tick interval

       // was the mouse button up prior to now?
       if (!m_left_button_down)
       {
           // is the button down now?
           m_left_button_down = (MouseButtons == MouseButtons.Left);

           if (m_left_button_down)
           {
               // the button was down and has now been released
               LeftButtonClickHandler();
           }
           else
           {
               // do nothing, the button has not been release yet
           }
       }
       else
       {
           // update the button state
           m_left_button_down = (MouseButtons == MouseButtons.Left);
       }
   }
   else if (temp_mof)
   {
       // the mouse just entered the form

       m_mouse_over_form = true;

       // set the initial state of the left button
       m_left_button_down = MouseButtons == MouseButtons.Left);
   }
   else
   {
       // the mouse is not currently over the form
       m_mouse_over_form = false;
       m_left_button_down = true;
   }
}

Answer 4

, , , - . , ( ), :

:

time.Interval = 250;
time.Tick += time_Tick;
time.Start();

tick :

void time_Tick(object sender, EventArgs e)
{
    switch (RectangleToScreen(Bounds).Contains(PointToScreen(Cursor.Position))) {
        case true:
            if (Opacity != .9999D)
                Opacity = .9999D;
            break;
        case false:
            if (Opacity != .5D)
                Opacity = .5D;
            break;
    }
}

Answer 5

Make the MouseEnter and MouseLeave event on the form and form elements; use a boolean value to determine if the mouse button was entered or left.

An example would be

    private static bool mouseEnteredForm

    private void Form1_MouseMove(object sender, MouseEventArgs e)
    {
        mouseEnteredForm = true;
        Form.MouseLeave += Form1_MouseLeave;
        CheckMouseLocation();
    }

    private void Form1_MouseLeave(object sender, MouseEventArgs e)
    {
        mouseEnteredForm = false
        CheckMouseLocation();
    }

    private static void CheckMouseLocation()
    {
        if(!mouseOverForm)
        {
            MessageBox.Show("Mouse Not Over Form!);
        }
        else if(mouseOverForm) //else if is optional. You could also use else in this case. I used else if for the sake of the example.
        {
            MessageBox.Show("Mouse Is Over Form");
        }
    }

This can be tedious if you have many objects in shape