我想在广场内点击，然后会出现“X”，但我不确定要在Form1_MouseDown，Form1_Paint和Form1_MouseUp事件中放置什么。我如何实现这个是C＃？
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace VTest
{
public partial class Form1 : Form
{
Rectangle rect; // single rect
int sqsize, n;
int margin;
public Form1()
{
n = 3;
margin = 25;
sqsize = 50;
rect = new Rectangle(10, 10, 150, 150);
InitializeComponent();
}
private void Form1_MouseDown(object sender, MouseEventArgs e)
{
// what goes here?
}
private void Form1_Paint(object sender, PaintEventArgs e)
{
// what goes here?
}
private void Form1_MouseUp(object sender, MouseEventArgs e)
{
// what goes here?
}
// ...
答案 0 :(得分：6)
在MouseDown事件中，确定是否在矩形内发生了点击很容易：
if (rect.Contains(e.Location))
{
// the user has clicked inside your rectangle
}
在表单上绘制“X”也很容易：
Graphics g = this.CreateGraphics();
g.DrawString("X", this.Font, SystemBrushes.WindowText,
(float)e.X, (float)e.Y);
然而，在这种情况下，“X”将不会持久，这意味着如果您在表单上拖动另一个表单然后将其移走，则“X”将不再存在。要绘制持久性“X”，请创建一个表单级的Point变量，如下所示：
private Point? _Xlocation = null;
如果用户点击了Rectangle：
，请使用MouseDown事件设置此变量if (rect.Contains(e.Location))
{
_Xlocation = e.Location;
this.Invalidate(); // this will fire the Paint event
}
然后，在表单的Paint事件中，绘制“X”：
if (_Xlocation != null)
{
e.Graphics.DrawString("X", this.Font, SystemBrushes.WindowText,
(float)e.X, (float)e.Y);
}
else
{
e.Graphics.Clear(this.BackColor);
}
如果您希望当用户放开鼠标按钮时“X”消失，只需将此代码放入MouseUp事件中：
_Xlocation = null;
this.Invalidate();
你可以根据自己的喜好变得更加复杂。使用此代码，“X”将在您单击表单的任何位置的下方和右侧绘制。如果您希望“X”在单击位置居中，您可以使用Graphics对象的MeasureString方法来确定“X”的高度和宽度，并相应地偏移DrawString位置
答案 1 :(得分：0)
您不需要mousedown和mouseup事件处理程序。
选择一个做出反应，我倾向于对MouseDown事件做出反应。
但是，当你想要查看MouseEventArgs属性时，你应该能够确定你是否在广场内。
您可能想要致电：
System.Diagnostics.Debug.WriteLine(...)
使用MouseEventArgs中的x和y属性，这样您就可以看到鼠标点击的位置，并确定您何时在广场上。
一旦你在那里，你就可以画出X。
您可能想要编写一个函数来绘制X并通过在300,300处绘制X来测试它，这样您就可以在尝试使用MouseDown时确保它看起来像。
答案 2 :(得分：0)
更新：我喜欢MusiGenesis演示的Rectangle.contains（location）方法。
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace DemoWindowApp
{
public partial class frmDemo : Form
{
Rectangle rec;
public frmDemo()
{
InitializeComponent();
}
private void frmDemo_Load(object sender, EventArgs e)
{
rec = new Rectangle(150,100,100,100);
}
private void frmDemo_Paint(object sender, PaintEventArgs e)
{
Pen p = new Pen(Color.Blue);
Graphics g = e.Graphics;
g.DrawRectangle(p,rec);
}
private void frmDemo_MouseMove(object sender, MouseEventArgs e)
{
if(rec.Contains(e.Location))
{
Cursor = Cursors.Cross;
}else
{
Cursor = Cursors.Default;
}
}
private void frmDemo_MouseDown(object sender, MouseEventArgs e)
{
if(rec.Contains(e.Location))
{
//mouse position adjust for window postion and border size.
//you may have to adjust the borders depending your
//windows theme
int x = MousePosition.X - this.Left - 4;
int y = MousePosition.Y - this.Top - 29;
Graphics g = this.CreateGraphics();
Pen p = new Pen(Color.Black);
Point p1 = new Point(x-10,y-10);
Point p2 = new Point(x+10,y+10);
Point p3 = new Point(x-10,y+10);
Point p4 = new Point(x+10,y-10);
g.DrawLines(p,new Point[]{p1,p2});
g.DrawLines(p,new Point[]{p3,p4});
}
}
}
}
答案 3 :(得分：0)
请参阅此处的代码：
using System;
using System.Drawing;
using System.Windows.Forms;
using System.Runtime.InteropServices;
namespace Demo_mousehook_csdn
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
MouseHook mh;
private void Form1_Load(object sender, EventArgs e)
{
mh = new MouseHook();
mh.SetHook();
mh.MouseMoveEvent += mh_MouseMoveEvent;
mh.MouseClickEvent += mh_MouseClickEvent;
mh.MouseDownEvent += mh_MouseDownEvent;
mh.MouseUpEvent += mh_MouseUpEvent;
}
private void mh_MouseDownEvent(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
richTextBox1.AppendText("Left Button Press\n");
}
if (e.Button == MouseButtons.Right)
{
richTextBox1.AppendText("Right Button Press\n");
}
}
private void mh_MouseUpEvent(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left)
{
richTextBox1.AppendText("Left Button Release\n");
}
if (e.Button == MouseButtons.Right)
{
richTextBox1.AppendText("Right Button Release\n");
}
}
private void mh_MouseClickEvent(object sender, MouseEventArgs e)
{
//MessageBox.Show(e.X + "-" + e.Y);
if (e.Button == MouseButtons.Left)
{
string sText = "(" + e.X.ToString() + "," + e.Y.ToString() + ")";
label1.Text = sText;
}
}
private void mh_MouseMoveEvent(object sender, MouseEventArgs e)
{
int x = e.Location.X;
int y = e.Location.Y;
textBox1.Text = x + "";
textBox2.Text = y + "";
}
private void Form1_FormClosed(object sender, FormClosedEventArgs e)
{
mh.UnHook();
}
private void Form1_FormClosed_1(object sender, FormClosedEventArgs e)
{
mh.UnHook();
}
private void richTextBox1_TextChanged(object sender, EventArgs e)
{
}
}
public class Win32Api
{
[StructLayout(LayoutKind.Sequential)]
public class POINT
{
public int x;
public int y;
}
[StructLayout(LayoutKind.Sequential)]
public class MouseHookStruct
{
public POINT pt;
public int hwnd;
public int wHitTestCode;
public int dwExtraInfo;
}
public delegate int HookProc(int nCode, IntPtr wParam, IntPtr lParam);
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
public static extern bool UnhookWindowsHookEx(int idHook);
[DllImport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
public static extern int CallNextHookEx(int idHook, int nCode, IntPtr wParam, IntPtr lParam);
}
public class MouseHook
{
private Point point;
private Point Point
{
get { return point; }
set
{
if (point != value)
{
point = value;
if (MouseMoveEvent != null)
{
var e = new MouseEventArgs(MouseButtons.None, 0, point.X, point.Y, 0);
MouseMoveEvent(this, e);
}
}
}
}
private int hHook;
private const int WM_MOUSEMOVE = 0x200;
private const int WM_LBUTTONDOWN = 0x201;
private const int WM_RBUTTONDOWN = 0x204;
private const int WM_MBUTTONDOWN = 0x207;
private const int WM_LBUTTONUP = 0x202;
private const int WM_RBUTTONUP = 0x205;
private const int WM_MBUTTONUP = 0x208;
private const int WM_LBUTTONDBLCLK = 0x203;
private const int WM_RBUTTONDBLCLK = 0x206;
private const int WM_MBUTTONDBLCLK = 0x209;
public const int WH_MOUSE_LL = 14;
public Win32Api.HookProc hProc;
public MouseHook()
{
this.Point = new Point();
}
public int SetHook()
{
hProc = new Win32Api.HookProc(MouseHookProc);
hHook = Win32Api.SetWindowsHookEx(WH_MOUSE_LL, hProc, IntPtr.Zero, 0);
return hHook;
}
public void UnHook()
{
Win32Api.UnhookWindowsHookEx(hHook);
}
private int MouseHookProc(int nCode, IntPtr wParam, IntPtr lParam)
{
Win32Api.MouseHookStruct MyMouseHookStruct = (Win32Api.MouseHookStruct)Marshal.PtrToStructure(lParam, typeof(Win32Api.MouseHookStruct));
if (nCode < 0)
{
return Win32Api.CallNextHookEx(hHook, nCode, wParam, lParam);
}
else
{
if (MouseClickEvent != null)
{
MouseButtons button = MouseButtons.None;
int clickCount = 0;
switch ((Int32)wParam)
{
case WM_LBUTTONDOWN:
button = MouseButtons.Left;
clickCount = 1;
MouseDownEvent(this, new MouseEventArgs(button, clickCount, point.X, point.Y, 0));
break;
case WM_RBUTTONDOWN:
button = MouseButtons.Right;
clickCount = 1;
MouseDownEvent(this, new MouseEventArgs(button, clickCount, point.X, point.Y, 0));
break;
case WM_MBUTTONDOWN:
button = MouseButtons.Middle;
clickCount = 1;
MouseDownEvent(this, new MouseEventArgs(button, clickCount, point.X, point.Y, 0));
break;
case WM_LBUTTONUP:
button = MouseButtons.Left;
clickCount = 1;
MouseUpEvent(this, new MouseEventArgs(button, clickCount, point.X, point.Y, 0));
break;
case WM_RBUTTONUP:
button = MouseButtons.Right;
clickCount = 1;
MouseUpEvent(this, new MouseEventArgs(button, clickCount, point.X, point.Y, 0));
break;
case WM_MBUTTONUP:
button = MouseButtons.Middle;
clickCount = 1;
MouseUpEvent(this, new MouseEventArgs(button, clickCount, point.X, point.Y, 0));
break;
}
var e = new MouseEventArgs(button, clickCount, point.X, point.Y, 0);
MouseClickEvent(this, e);
}
this.Point = new Point(MyMouseHookStruct.pt.x, MyMouseHookStruct.pt.y);
return Win32Api.CallNextHookEx(hHook, nCode, wParam, lParam);
}
}
public delegate void MouseMoveHandler(object sender, MouseEventArgs e);
public event MouseMoveHandler MouseMoveEvent;
public delegate void MouseClickHandler(object sender, MouseEventArgs e);
public event MouseClickHandler MouseClickEvent;
public delegate void MouseDownHandler(object sender, MouseEventArgs e);
public event MouseDownHandler MouseDownEvent;
public delegate void MouseUpHandler(object sender, MouseEventArgs e);
public event MouseUpHandler MouseUpEvent;
}
}
在此演示中，您可以检测鼠标的实时位置，并检测mouseup / domn事件。它将在此演示中的richtextbox上显示。
有关鼠标事件的更多教程或下载此演示you can see here.