ZedGraph控件第二节：

 第二节：ModInitialSampleDemo.cs介绍

为了讲解方便，我先附上源代码和效果图。

代码如下：

using System;

using System.Drawing;

using System.Collections;

 

using ZedGraph;

 

namespace ZedGraph.Demo

{

     ///<summary>

     /// Summary description for SimpleDemo.

     ///</summary>

     public class ModInitialSampleDemo : DemoBase

     {

 

           public ModInitialSampleDemo() : base( "Code Project Modified Initial Sample",

                "Modified Initial Sample", DemoType.Tutorial )

           {

                GraphPane myPane = base.GraphPane;

 

                // Set up the title and axis labels

                myPane.Title = "My Test Graph\n(For CodeProject Sample)";

                myPane.XAxis.Title = "My X Axis";

                myPane.YAxis.Title = "My Y Axis";

               

                // Make up some data arrays based on the Sine function

                PointPairList list1 = new PointPairList();

                PointPairList list2 = new PointPairList();

                for ( int i=0; i<36; i++ )

                {

                     double x = (double) i + 5;

                     double y1 = 1.5 + Math.Sin( (double) i * 0.2 );

                     double y2 = 3.0 * ( 1.5 + Math.Sin( (double) i * 0.2 ) );

                     list1.Add( x, y1 );

                     list2.Add( x, y2 );

                }

 

                // Generate a red curve with diamond

                // symbols, and "Porsche" in the legend

                LineItem myCurve = myPane.AddCurve( "Porsche",

                     list1, Color.Red, SymbolType.Diamond );

 

                // Generate a blue curve with circle

                // symbols, and "Piper" in the legend

                LineItem myCurve2 = myPane.AddCurve( "Piper",

                     list2, Color.Blue, SymbolType.Circle );

 

                // Change the color of the title

                myPane.FontSpec.FontColor = Color.Green;

 

                // Add gridlines to the plot, and make them gray

                myPane.XAxis.IsShowGrid = true;

                myPane.YAxis.IsShowGrid = true;

                myPane.XAxis.GridColor = Color.LightGray;

                myPane.YAxis.GridColor = Color.LightGray;

 

                // Move the legend location

                base.Pane.Legend.Position = ZedGraph.LegendPos.Bottom;

 

                // Make both curves thicker

                myCurve.Line.Width = 2.0F;

                myCurve2.Line.Width = 2.0F;

 

                // Fill the area under the curves

                myCurve.Line.Fill = new Fill( Color.White, Color.Red, 45F );

                myCurve2.Line.Fill = new Fill( Color.White, Color.Blue, 45F );

 

                // Increase the symbol sizes, and fill them with solid white

                myCurve.Symbol.Size = 8.0F;

                myCurve2.Symbol.Size = 8.0F;

                myCurve.Symbol.Fill = new Fill( Color.Red );

                myCurve2.Symbol.Fill = new Fill( Color.White );

 

                // Add a background gradient fill to the axis frame

                myPane.AxisFill = new Fill( Color.White,

                     Color.FromArgb( 255, 255, 210), -45F );

 

                // Add a caption and an arrow

                TextItem myText = new TextItem( "Interesting\nPoint", 23F, 7F );

                myText.FontSpec.FontColor = Color.Red;

                myText.Location.AlignH = AlignH.Center;

                myText.Location.AlignV = AlignV.Top;

                myPane.GraphItemList.Add( myText );

                ArrowItem myArrow = new ArrowItem( Color.Red, 12F, 7F, 5F, 20F, 8F );

                myPane.GraphItemList.Add( myArrow );

 

                base.ZedGraphControl.AxisChange();

           }

     }

}

        我们可以看到，这个例子和第一节中的例子大部分都相同，我在这只讲它们不同的地方，和不好懂的地方。

        和第一节的图相比，本节的图在Pane上添加了Grid的显示，其功能要归功于如下代码：

                myPane.XAxis.IsShowGrid = true;

                myPane.YAxis.IsShowGrid = true;

                myPane.XAxis.GridColor = Color.LightGray;

                myPane.YAxis.GridColor = Color.LightGray;

代码一目了然，我就不用多解释什么了，要说的是注意在ZedGraph中，很多都是有缺省值的，IsShowGrid的缺省值就是false，所以第一节中没有对此项进行设置就没有显示Grid。

 

上节我就已经说过

LineItem myCurve = myPane.AddCurve( "Porsche",list1, Color.Red, SymbolType.Diamond );

myCurve接收myPane.AddCurve的返回值后就可以对里面的线图作近一步的描述，

myCurve.Line.Width = 2.0F;、myCurve.Line.Fill = new Fill( Color.White, Color.Red, 45F ); 和myCurve.Symbol.Fill = new Fill( Color.Red );

就是其中的三个应用，一个是Line的宽度，第二个表示Line要填充下面的区域，以45度角从左到右从白到红的填充，第三个表示线图上的符号被填充成什么颜色的。效果见下图：

 

关于Legend的类请见下图：

base.Pane.Legend.Position = ZedGraph.LegendPos.Bottom;

就是显示Pane中的图形的名字，它里面也有很多属性和方法，如果大家写上base.Pane.Legend.IsVisible = false ;那么就可以隐藏图形的名字。

 

TextItem类的主要方法是在Pane中显示一个textbox的文本框，见上图

 

ArrowItem类的主要方法是在Pane上显示一个箭头，

ArrowItem myArrow = new ArrowItem( Color.Red, 12F, 7F, 5F, 20F, 8F );

构造函数的参数含义分别为颜色，箭头的大小，箭头的起始(x,y)，终止(x,y)。