C#教程：MouseMove事件使用实例|方法
MouseMove事件
当鼠标指针移到控件上时发生MouseMove事件。
语法：
public event MouseEventHandler MouseMove
示例
MouseMove事件的使用
本示例实现的是在窗体的鼠标MouseMove事件中，实现画板功能。示例运行结果如图1所示。
图1 MouseMove事件的使用
private void Form1_MouseMove(object sender, MouseEventArgs e)
{
if (lastPoint.Equals(Point.Empty))
{ lastPoint = new Point(e.X, e.Y); }
if (OnMouseDown)
{
Point cruuPoint = new Point(e.X, e.Y);
graphics.DrawLine(pen, cruuPoint, lastPoint);
}
lastPoint = new Point(e.X, e.Y);
}
完整程序代码如下：
★ ★★★★frmMouse.cs窗体代码文件完整程序代码★★★★★
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace _2_05
{
public partial class frmMouse : Form
{
public frmMouse()
{
InitializeComponent();
pen = new Pen(Color.FromName(G_str_color));//始末画笔
graphics = CreateGraphics();//初始画板
}
public bool G_OnMouseDown = false;
public Point lastPoint = Point.Empty;
public string G_str_color = "black";
public Pen pen;
public Graphics graphics;
//当你拖拽鼠标处理的和序,当没有上一点时,你目当所按下的点就是上一个点
//目当所按下的点就是CurrPoint,使用您所选反背景色画笔pen从lastPointi画一条直线,然后将
//上一个点LastPoint的值设为目前点currPoint
private void Form1_MouseMove(object sender, MouseEventArgs e)
{
if (lastPoint.Equals(Point.Empty))
{ lastPoint = new Point(e.X, e.Y); }
if (G_OnMouseDown)
{
Point cruuPoint = new Point(e.X, e.Y);
graphics.DrawLine(pen, cruuPoint, lastPoint);
}
lastPoint = new Point(e.X, e.Y);
}
//当鼠标离开时把布尔变量设为false;
private void Form1_MouseUp(object sender, MouseEventArgs e)
{
G_OnMouseDown = false;
}
//将布尔变量OnMouseDown设为true 按下鼠标右键时显示菜单
private void Form1_MouseDown(object sender, MouseEventArgs e)
{
G_OnMouseDown = true;
if (e.Button == MouseButtons.Right)
{
this.contextMenuStrip1.Show(this, new Point(e.X, e.Y));
}
}
#region 获取背景色名称后转成Color对象充当Pen构造函数的自变量,用于创建画笔对象Pen
private void whiteToolStripMenuItem_Click(object sender, EventArgs e)
{
G_str_color = ((ToolStripMenuItem)sender).Text;
pen = new Pen(Color.FromName(G_str_color));
}
private void redToolStripMenuItem_Click(object sender, EventArgs e)
{
G_str_color = ((ToolStripMenuItem)sender).Text;
pen = new Pen(Color.FromName(G_str_color));
}
private void greenToolStripMenuItem_Click(object sender, EventArgs e)
{
G_str_color = ((ToolStripMenuItem)sender).Text;
pen = new Pen(Color.FromName(G_str_color));
}
private void blackToolStripMenuItem_Click(object sender, EventArgs e)
{
G_str_color = ((ToolStripMenuItem)sender).Text;
pen = new Pen(Color.FromName(G_str_color));
}
private void blueToolStripMenuItem_Click(object sender, EventArgs e)
{
G_str_color = ((ToolStripMenuItem)sender).Text;
pen = new Pen(Color.FromName(G_str_color));
}
#endregion
private void frmMouse_Load(object sender, EventArgs e)
{
}
}
}
★ ★★★★frmMouse.Designer.cs窗体设计文件完整程序代码★★★★★
namespace _2_05
{
partial class frmMouse
{
///
/// 必需的设计器变量。
///
private System.ComponentModel.IContainer components = null;
///
/// 清理所有正在使用的资源。
///
/// 如果应释放托管资源，为 true；否则为 false。
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}
#region Windows 窗体设计器生成的代码
///
/// 设计器支持所需的方法 - 不要
/// 使用代码编辑器修改此方法的内容。
///
