如何仅获取可见曲线数据的PointPairList,而不是Curveitem列表中的所有点?缩放或平移时,此列表应动态更改。
谢谢。
最佳答案
似乎没有ZedGraph API方法可以为您执行此操作。但是,下面的代码演示了一个VisiblePoints方法,该方法返回PointPairList并在一个非常特定的ZedGraph用例下工作。
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Windows.Forms;
using ZedGraph;
namespace ZedGraphMain
{
public class ZedGraphDemo : Form
{
public ZedGraphDemo()
{
var graphControl = new ZedGraphControl();
graphControl.Dock = DockStyle.Fill;
graphControl.IsShowPointValues = true;
Controls.Add(graphControl);
var points = new PointPairList();
for (double i = 0; i <= 5.0; i += 1)
points.Add(i, i);
var curve = graphControl.GraphPane.AddCurve("A Label", points, Color.ForestGreen);
graphControl.RestoreScale(graphControl.GraphPane);
graphControl.ZoomEvent += (_, __, ___) => LogVisibility(graphControl, curve, points);
}
private static PointPairList VisiblePoints(ZedGraphControl control, LineItem lineItem, PointPairList points)
{
var pointPairList = new PointPairList();
pointPairList.AddRange(points.Where(pp => IsVisible(control, lineItem, pp)).ToList());
return pointPairList;
}
private static bool IsVisible(ZedGraphControl control, LineItem lineItem, PointPair point)
{
GraphPane pane = control.GraphPane;
Scale xScale = lineItem.GetXAxis(pane).Scale;
Scale yScale = lineItem.GetYAxis(pane).Scale;
return point.X > xScale.Min && point.X < xScale.Max && point.Y > yScale.Min && point.Y < yScale.Max;
}
private static void LogVisibility(ZedGraphControl control, LineItem lineItem, PointPairList points)
{
List<PointPair> visiblePoints = VisiblePoints(control, lineItem, points);
Console.Out.WriteLine(DateTime.Now + ": " + string.Join(",", visiblePoints.Select(pp => string.Format("({0:N1}, {1:N1})", pp.X, pp.Y))));
}
}
}