usingSystem;usingSystem.Collections.Generic;usingSystem.Drawing;usingSystem.Drawing.Drawing2D;usingSystem.Windows.Forms;namespaceWinFormsApp2{publicpartialclassForm1:Form{// 存储实时数据的集合privateList<int>_dataPoints=newList<int>();// 绘图区域的尺寸和边距privatereadonlyint_paddingLeft=40;// 左内边距（纵轴文字）privatereadonlyint_paddingRight=10;// 右内边距privatereadonlyint_paddingTop=10;// 上内边距privatereadonlyint_paddingBottom=30;// 下内边距（横轴文字）// 坐标系参数privatereadonlyint_maxYValue=100;// Y轴最大值privatereadonlyint_minYValue=0;// Y轴最小值（X轴对应值）privatereadonlyint_xAxisMaxPoints=40;// X轴最大显示点数（0-40）privatereadonlyint_gridIntervalY=20;// Y轴网格线间隔privatereadonlyint_gridIntervalX=5;// X轴网格线间隔// 定时器（模拟实时数据）privateSystem.Windows.Forms.Timer_dataTimer;publicForm1(){InitializeComponent();InitForm();InitTimer();}/// <summary>/// 初始化窗体和绘图面板/// </summary>privatevoidInitForm(){this.Text="实时折线图（GDI+）";this.Size=newSize(800,600);// 创建绘图面板PanelchartPanel=newPanel();chartPanel.Dock=DockStyle.Fill;chartPanel.BackColor=Color.White;chartPanel.Paint+=ChartPanel_Paint;// 绑定绘制事件this.Controls.Add(chartPanel);}/// <summary>/// 初始化定时器（模拟每秒添加一个随机数据）/// </summary>privatevoidInitTimer(){_dataTimer=newSystem.Windows.Forms.Timer();_dataTimer.Interval=1000;// 1秒触发一次_dataTimer.Tick+=(s,e)=>{Randomrandom=newRandom();intnewData=random.Next(_minYValue,_maxYValue);AddRealTimeData(newData);};_dataTimer.Start();}/// <summary>/// 添加实时数据并刷新绘图/// </summary>/// <param name="value">新数据值</param>publicvoidAddRealTimeData(intvalue){// 强制数据≥X轴对应的值（0）intvalidValue=Math.Max(value,_minYValue);_dataPoints.Add(validValue);// 严格限制数据长度为_xAxisMaxPoints，避免超界if(_dataPoints.Count>_xAxisMaxPoints){_dataPoints.RemoveAt(0);}this.Controls[0].Invalidate();}/// <summary>/// 核心绘制逻辑/// </summary>privatevoidChartPanel_Paint(objectsender,PaintEventArgse){Panelpanel=senderasPanel;if(panel==null)return;// 开启双缓冲，避免绘图闪烁e.Graphics.SmoothingMode=SmoothingMode.AntiAlias;e.Graphics.Clear(Color.White);// 计算实际绘图区域（扣除边距）RectangledrawArea=newRectangle(_paddingLeft,_paddingTop,panel.Width-_paddingLeft-_paddingRight,panel.Height-_paddingTop-_paddingBottom);// 1. 绘制网格线DrawGridLines(e.Graphics,drawArea);// 2. 绘制坐标轴DrawAxis(e.Graphics,drawArea);// 3. 绘制折线（至少2个点才绘制）if(_dataPoints.Count>=2){DrawLineChart(e.Graphics,drawArea);}}/// <summary>/// 绘制网格线/// </summary>privatevoidDrawGridLines(Graphicsg,RectangledrawArea){PengridPen=newPen(Color.LightGray,1);// Y轴网格线（水平）floatyStep=drawArea.Height/(float)(_maxYValue-_minYValue)*_gridIntervalY;for(inty=_gridIntervalY;y<_maxYValue;y+=_gridIntervalY){floatyPos=drawArea.Bottom-(y-_minYValue)*(drawArea.Height/(float)(_maxYValue-_minYValue));g.DrawLine(gridPen,drawArea.Left,yPos,drawArea.Right,yPos);}// X轴网格线（垂直）floatxStep=drawArea.Width/(float)_xAxisMaxPoints*_gridIntervalX;for(intx=_gridIntervalX;x<_xAxisMaxPoints;x+=_gridIntervalX){floatxPos=drawArea.Left+x*(drawArea.Width/(float)_xAxisMaxPoints);g.DrawLine(gridPen,xPos,drawArea.Top,xPos,drawArea.Bottom);}gridPen.Dispose();}/// <summary>/// 绘制坐标轴（X/Y轴 + 刻度文字）/// </summary>privatevoidDrawAxis(Graphicsg,RectangledrawArea){PenaxisPen=newPen(Color.Black,2);FontaxisFont=newFont("Arial",8);BrushtextBrush=Brushes.Black;// 绘制Y轴（纵轴）g.DrawLine(axisPen,drawArea.Left,drawArea.Top,drawArea.Left,drawArea.Bottom);// Y轴刻度文字for(inty=_minYValue;y<=_maxYValue;y+=_gridIntervalY){floatyPos=drawArea.Bottom-(y-_minYValue)*(drawArea.Height/(float)(_maxYValue-_minYValue));stringyText=y.ToString();SizeFtextSize=g.MeasureString(yText,axisFont);g.DrawString(yText,axisFont,textBrush,drawArea.Left-textSize.Width-5,yPos-textSize.Height/2);}// 绘制X轴（横轴）g.DrawLine(axisPen,drawArea.Left,drawArea.Bottom,drawArea.Right,drawArea.Bottom);// X轴刻度文字for(intx=0;x<=_xAxisMaxPoints;x+=_gridIntervalX){// 核心校准：X轴刻度文字的坐标和折线坐标用同一套计算逻辑floatxPos=drawArea.Left+(x*drawArea.Width)/(float)_xAxisMaxPoints;stringxText=x.ToString();SizeFtextSize=g.MeasureString(xText,axisFont);g.DrawString(xText,axisFont,textBrush,xPos-textSize.Width/2,drawArea.Bottom+5);}axisPen.Dispose();axisFont.Dispose();}/// <summary>/// 绘制折线（彻底修复X轴超界问题）/// </summary>privatevoidDrawLineChart(Graphicsg,RectangledrawArea){PenlinePen=newPen(Color.Red,2);List<PointF>pointList=newList<PointF>();// 遍历数据点，精准映射坐标for(inti=0;i<_dataPoints.Count;i++){// #################### 核心修复 ####################// 原逻辑：x = drawArea.Left + i * (drawArea.Width / _xAxisMaxPoints)// 问题：当i=_xAxisMaxPoints时，x = drawArea.Left + drawArea.Width → 超出drawArea.Right// 新逻辑：按比例映射，i对应X轴刻度值（0~40），确保最后一个点落在drawArea.Rightfloatx=drawArea.Left+(i*drawArea.Width)/(float)_xAxisMaxPoints;// 双重兜底：确保X坐标不超出绘图区域x=Math.Clamp(x,drawArea.Left,drawArea.Right);// Y坐标计算（确保不低于X轴、不高于上边界）floaty=drawArea.Bottom-(_dataPoints[i]-_minYValue)*(drawArea.Height/(float)(_maxYValue-_minYValue));y=Math.Clamp(y,drawArea.Top,drawArea.Bottom);// 用Clamp简化边界限制pointList.Add(newPointF(x,y));}// 绘制折线g.DrawLines(linePen,pointList.ToArray());linePen.Dispose();}// 窗体关闭时停止定时器，释放资源protectedoverridevoidOnFormClosing(FormClosingEventArgse){_dataTimer?.Stop();_dataTimer?.Dispose();base.OnFormClosing(e);}}}
