C# GDI在控件上绘图的方法
本文以在chart控件上和窗体上画矩形为例子讲述了C#GDI在控件上绘图的方法。分享给大家供大家参考。具体方法如下：
具体的实现方法就不多解释了，备注很详细，代码也很简单。
主要功能代码如下：
usingSystem;
usingSystem.Collections.Generic;
usingSystem.ComponentModel;
usingSystem.Data;
usingSystem.Drawing;
usingSystem.Linq;
usingSystem.Text;
usingSystem.Windows.Forms;
usingSystem.IO;
usingSystem.Configuration;
namespaceWFApp2
{
publicpartialclassdata:Form
{
publicdata()
{
InitializeComponent();
//窗体
g=this.CreateGraphics();
//chart控件
g2=this.chart1.CreateGraphics();
}
publicPointfirstPoint=newPoint(0,0);//鼠标第一点
publicPointsecondPoint=newPoint(0,0);//鼠标第二点
publicboolbegin=false;//是否开始画矩形
///<summary>
///在from上画矩形
///</summary>
Graphicsg;
///<summary>
///在chart1控件上画矩形
///</summary>
Graphicsg2;
///<summary>
///在窗体上按下鼠标事件
///</summary>
///<paramname="sender"></param>
///<paramname="e"></param>
privatevoiddata_MouseDown(objectsender,MouseEventArgse)
{
begin=true;
firstPoint=newPoint(e.X,e.Y);
}
///<summary>
///在窗体上鼠标移动开始绘图
///</summary>
///<paramname="sender"></param>
///<paramname="e"></param>
privatevoiddata_MouseMove(objectsender,MouseEventArgse)
{
if(begin)
{
//清除窗体绘图面,相当于刷新了一次窗体界面然后重新绘制
g.Clear(this.BackColor);
//获取新的右下角坐标
secondPoint=newPoint(e.X,e.Y);
//获取两个数中的大者或小者
intminX=Math.Min(firstPoint.X,secondPoint.X);
intminY=Math.Min(firstPoint.Y,secondPoint.Y);
intmaxX=Math.Max(firstPoint.X,secondPoint.X);
intmaxY=Math.Max(firstPoint.Y,secondPoint.Y);
//画框
g.DrawRectangle(newPen(Color.Red),minX,minY,maxX-minX,maxY-minY);
//ControlPaint.DrawReversibleFrame(newRectangle(minX,minY,maxX-minX,maxY-minY),this.BackColor,FrameStyle.Dashed);
}
}
///<summary>
///鼠标松开停止绘图
///</summary>
///<paramname="sender"></param>
///<paramname="e"></param>
privatevoiddata_MouseUp(objectsender,MouseEventArgse)
{
begin=false;
}
///<summary>
///在chart控件上移动鼠标绘图
///</summary>
///<paramname="sender"></param>
///<paramname="e"></param>
privatevoidchart1_MouseMove(objectsender,MouseEventArgse)
{
if(begin)
{
//重新在chart上面绘图，此处不能用clear方法，clear会清除整个绘图界面chart控件会被清除
this.Refresh();
//获取新的右下角坐标
secondPoint=newPoint(e.X,e.Y);
intminX=Math.Min(firstPoint.X,secondPoint.X);
intminY=Math.Min(firstPoint.Y,secondPoint.Y);
intmaxX=Math.Max(firstPoint.X,secondPoint.X);
intmaxY=Math.Max(firstPoint.Y,secondPoint.Y);
//画矩形
g2.DrawRectangle(newPen(Color.Red),minX,minY,maxX-minX,maxY-minY);
}
}
///<summary>
///鼠标松开停止绘图
///</summary>
///<paramname="sender"></param>
///<paramname="e"></param>
privatevoidchart1_MouseUp(objectsender,MouseEventArgse)
{
begin=false;
}
///<summary>
///在chart控件上按下鼠标
///</summary>
///<paramname="sender"></param>
///<paramname="e"></param>
privatevoidchart1_MouseDown(objectsender,MouseEventArgse)
{
begin=true;
firstPoint=newPoint(e.X,e.Y);
}
}
}
希望本文所述对大家的C#程序设计有所帮助