【TeeChart .NET教程】（十三）圖表面板上的自定義繪圖

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【下載TeeChart.Net最新版本】

TeeChart通過Canvas對(duì)象提供廣泛的自定義繪圖工具，使用Canvas，您可以在“ Chart Panel圖表面板”的任何位置添加形狀，線條和文本，并定義其顏色，筆和畫筆樣式。

（一）TeeChart Canvas——TeeChart 畫布

1.1 繪圖順序

使用TeeChart的Canvas方法時(shí)，繪圖順序很重要，在圖表上繪制一條線然后添加系列數(shù)據(jù)點(diǎn)將導(dǎo)致線拉過度 。有四個(gè)主要的圖表繪制事件，按順序排列：

• BeforeDraw event
• BeforeDrawAxes event
• BeforeDrawSeries event
• AfterDraw event

例：

[C#.Net]

private bool afterDraw; 
private bool beforeDraw; 
private bool beforeDrawAxis; 
private bool beforeDrawSeries; 
 
private void Form1_Load(object sender, System.EventArgs e) {  
     SetFlags(ref beforeDraw); 
     Bar bar1 = new Bar(tChart1.Chart); 
     bar1.FillSampleValues(20); 
     radioButton1.Checked = true; 
} 
private void SetFlags(ref bool Flag) { 
     beforeDraw = false; 
     afterDraw = false; 
     beforeDrawAxis = false; 
     beforeDrawSeries = false; 
     Flag = true; 
} 
private void DrawShape(Steema.TeeChart.Drawing.Graphics3D gg) { 
     gg.Brush.Color = Color.Yellow; 
     gg.Pen.Visible = true; 
     gg.Pen.Style = System.Drawing.Drawing2D.DashStyle.Dash; 
     gg.Brush.Visible = true; 
     gg.Ellipse(1,1,gg.Chart.Width - 1,gg.Chart.Height - 1); 
} 
private void tChart1_AfterDraw(object sender, Steema.TeeChart.Drawing.Graphics3D g) { 
     if(afterDraw) { 
     DrawShape(g); 
    } 
} 
private void tChart1_BeforeDraw(object sender, Steema.TeeChart.Drawing.Graphics3D g) { 
     if(beforeDraw) { 
     DrawShape(g); 
    } 
} 
private void tChart1_BeforeDrawAxes(object sender, Steema.TeeChart.Drawing.Graphics3D g) { 
     if(beforeDrawAxis) { 
     DrawShape(g); 
    } 
} 
private void tChart1_BeforeDrawSeries(object sender, Steema.TeeChart.Drawing.Graphics3D g) { 
     if(beforeDrawSeries) { 
     DrawShape(g); 
    } 
} 
private void radioButton4_Click(object sender, System.EventArgs e) { 
     SetFlags(ref afterDraw); 
     tChart1.Refresh(); 
} 
private void radioButton3_Click(object sender, System.EventArgs e) { 
     SetFlags(ref beforeDrawSeries); 
     tChart1.Refresh(); 
} 
private void radioButton2_Click(object sender, System.EventArgs e) { 
     SetFlags(ref beforeDrawAxis); 
     tChart1.Refresh(); 
} 
private void radioButton1_Click(object sender, System.EventArgs e) { 
     SetFlags(ref beforeDraw); 
     tChart1.Refresh(); 
}

[VB.Net]

Private BeforeDraw As Boolean 
Private BeforeDrawAxis As Boolean 
Private BeforeDrawSeries As Boolean 
Private AfterDraw As Boolean 
 
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
    SetFlags(BeforeDraw) 
    Dim Bar1 As New Steema.TeeChart.Styles.Bar(TChart1.Chart) 
    Bar1.FillSampleValues(20) 
    RadioButton1.Checked = True 
End Sub 
Private Sub SetFlags(ByRef Flag As Boolean) 
    BeforeDraw = False 
    BeforeDrawAxis = False 
    BeforeDrawSeries = False 
    AfterDraw = False 
    Flag = True 
End Sub 
Private Sub DrawShape(ByVal gg As Steema.TeeChart.Drawing.Graphics3D) 
    gg.Brush.Color = Color.Yellow 
    gg.Pen.Visible = True 
    gg.Pen.Style = Drawing.Drawing2D.DashStyle.Dash 
    gg.Brush.Visible = True 
    gg.Ellipse(1, 1, gg.Chart.Width - 1, gg.Chart.Height - 1) 
End Sub 
Private Sub TChart1_AfterDraw(ByVal sender As Object, ByVal g As Steema.TeeChart.Drawing.Graphics3D) Handles TChart1.AfterDraw 
    If AfterDraw = True Then 
     DrawShape(g) 
    End If 
End Sub 
Private Sub TChart1_BeforeDraw(ByVal sender As Object, ByVal g As Steema.TeeChart.Drawing.Graphics3D) Handles TChart1.BeforeDraw 
    If BeforeDraw = True Then 
     DrawShape(g) 
    End If 
End Sub 
Private Sub TChart1_BeforeDrawAxes(ByVal sender As Object, ByVal g As Steema.TeeChart.Drawing.Graphics3D) Handles TChart1.BeforeDrawAxes 
    If BeforeDrawAxis = True Then 
     DrawShape(g) 
    End If 
End Sub 
Private Sub TChart1_BeforeDrawSeries(ByVal sender As Object, ByVal g As Steema.TeeChart.Drawing.Graphics3D) Handles TChart1.BeforeDrawSeries 
    If BeforeDrawSeries = True Then 
     DrawShape(g) 
    End If 
End Sub 
Private Sub RadioButton4_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles RadioButton4.Click 
    SetFlags(AfterDraw) 
    TChart1.Refresh() 
End Sub 
Private Sub RadioButton3_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles RadioButton3.Click 
    SetFlags(BeforeDrawSeries) 
    TChart1.Refresh() 
End Sub 
Private Sub RadioButton2_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles RadioButton2.Click 
    SetFlags(BeforeDrawAxis) 
    TChart1.Refresh() 
End Sub 
Private Sub RadioButton1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles RadioButton1.Click 
    SetFlags(BeforeDraw) 
    TChart1.Refresh() 
End Sub

1.2 確保將自定義繪制的項(xiàng)目保存到Canvas

 

如果不在其中一個(gè)Chart事件中調(diào)用Canvas繪制代碼，則自定義繪圖將不會(huì)永久保存到Canvas，從而導(dǎo)致在應(yīng)用程序最小化時(shí)丟失任何添加內(nèi)容或另一個(gè)窗口放在它上面。您的代碼不需要直接駐留在Chart事件中; 如果將代碼放在BeforeDrawSeries / AfterDraw中并且檢查運(yùn)行時(shí)設(shè)置的標(biāo)記，則可以在圖表窗口的生命周期中保存用戶繪制的項(xiàng)目。當(dāng)活動(dòng)標(biāo)記為true時(shí)，繪制方法因此運(yùn)行繪制代碼，如上例所示。

 

1.3 繪制線

添加一個(gè)畫布線：示例（從左上角到右下角對(duì)角畫一條線）

[C#.Net]

private void Form1_Load(object sender, System.EventArgs e) { 
        line1.FillSampleValues(20); 
        line1.VertAxis = VerticalAxis.Both; 
        line1.HorizAxis = HorizontalAxis.Both; 
        tChart1.Aspect.View3D = false; 
} 
 
private void tChart1_AfterDraw(object sender, Steema.TeeChart.Drawing.Graphics3D g) { 
        Point s = new Point(tChart1.Axes.Left.Position, tChart1.Axes.Top.Position); 
        Point e = new Point(tChart1.Axes.Right.Position, tChart1.Axes.Bottom.Position); 
        g.MoveTo(s); 
        g.LineTo(e,0); 
} 

[VB.Net]

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
        Line1.FillSampleValues(20) 
        Line1.VertAxis = Steema.TeeChart.VerticalAxis.Both 
        Line1.HorizAxis = Steema.TeeChart.HorizontalAxis.Both 
        TChart1.Aspect.View3D = False 
End Sub 
 
Private Sub TChart1_AfterDraw(ByVal sender As Object, ByVal g As Steema.TeeChart.Drawing.Graphics3D) Handles TChart1.AfterDraw 
        Dim S As New Point(TChart1.Axes.Left.Position, TChart1.Axes.Top.Position) 
        Dim E As New Point(TChart1.Axes.Right.Position, TChart1.Axes.Bottom.Position) 
        g.MoveTo(S) 
        g.LineTo(E, 0) 
End Sub

在3D圖表上，由于3D正交位移，軸位置偏離圖表區(qū)域?？梢韵鄳?yīng)地移動(dòng)線：示例（在3D圖表的圖表區(qū)域中從左上角到右下角對(duì)角繪制一條線）

[C#.Net]

private void Form1_Load(object sender, System.EventArgs e) { 
        line1.FillSampleValues(20); 
        line1.VertAxis = VerticalAxis.Both; 
        line1.HorizAxis = HorizontalAxis.Both; 
        tChart1.Aspect.Chart3DPercent = 50; 
} 
 
private void tChart1_AfterDraw(object sender, Steema.TeeChart.Drawing.Graphics3D g) { 
        Steema.TeeChart.Drawing.Point3D s = new Steema.TeeChart.Drawing.Point3D(); 
        s.X = tChart1.Axes.Left.Position; 
        s.Y = tChart1.Axes.Top.Position; 
        s.Z = 0; 
 
        Steema.TeeChart.Drawing.Point3D e = new Steema.TeeChart.Drawing.Point3D(); 
        e.X = tChart1.Axes.Right.Position; 
        e.Y = tChart1.Axes.Bottom.Position; 
        e.Z = tChart1.Aspect.Width3D; 
     
        g.MoveTo(s); 
        g.LineTo(e); 
}

[VB.Net]

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
        Line1.FillSampleValues(20) 
        Line1.VertAxis = Steema.TeeChart.VerticalAxis.Both 
        Line1.HorizAxis = Steema.TeeChart.HorizontalAxis.Both 
        TChart1.Aspect.Chart3DPercent = 50 
End Sub 
 
Private Sub TChart1_AfterDraw(ByVal sender As Object, ByVal g As Steema.TeeChart.Drawing.Graphics3D) Handles TChart1.AfterDraw 
        Dim S As New Steema.TeeChart.Drawing.Point3D() 
        S.X = TChart1.Axes.Left.Position 
        S.Y = TChart1.Axes.Top.Position 
        S.Z = 0 
 
        Dim E As New Steema.TeeChart.Drawing.Point3D() 
        E.X = TChart1.Axes.Right.Position 
        E.Y = TChart1.Axes.Bottom.Position 
        E.Z = TChart1.Aspect.Width3D 
 
        g.MoveTo(S) 
        g.LineTo(E) 
End Sub

1.4 畫布筆和畫筆

上面的線是使用為繪制線之前繪制的最后一個(gè)對(duì)象定義的筆和畫筆繪制的。那可能是也可能不是你想要的筆。相應(yīng)地更改筆：示例（在繪制線之前定義筆）

[C#.Net]

private void tChart1_AfterDraw(object sender, Steema.TeeChart.Drawing.Graphics3D g) { 
        Point p5 = new Point(line1.CalcXPos(5), line1.CalcYPos(5)); 
        Point p15 = new Point(line1.CalcXPos(15), line1.CalcYPos(15)); 
        g.Pen.DashCap = System.Drawing.Drawing2D.DashCap.Triangle; 
        g.Pen.EndCap = System.Drawing.Drawing2D.LineCap.DiamondAnchor; 
        g.Pen.Style = System.Drawing.Drawing2D.DashStyle.DashDotDot; 
        g.Pen.Transparency = 70; 
        g.Pen.Width = 3; 
        g.Pen.Color = Color.BlueViolet; 
        g.MoveTo(p5); 
        g.LineTo(p15, 0); 
}

[VB.Net]

Private Sub TChart1_AfterDraw(ByVal sender As Object, ByVal g As Steema.TeeChart.Drawing.Graphics3D) Handles TChart1.AfterDraw 
        Dim P5 As New Point(Line1.CalcXPos(5), Line1.CalcYPos(5)) 
        Dim P15 As New Point(Line1.CalcXPos(15), Line1.CalcYPos(15)) 
        g.Pen.DashCap = System.Drawing.Drawing2D.DashCap.Triangle 
        g.Pen.EndCap = System.Drawing.Drawing2D.LineCap.DiamondAnchor 
        g.Pen.Style = System.Drawing.Drawing2D.DashStyle.DashDotDot 
        g.Pen.Transparency = 70 
        g.Pen.Width = 3 
        g.Pen.Color = Color.BlueViolet 
        g.MoveTo(P5) 
        g.LineTo(P15, 0) 
End Sub

1.5 添加2D形狀

以與Canvas Lines類似的方式添加Canvas Shapes。以下示例在圖表區(qū)域的中心添加一個(gè)Rectangle：

1.5.1 2D圖表

2D圖表僅支持2D形狀，例：

[C#.Net]

private void tChart1_AfterDraw(object sender, Steema.TeeChart.Drawing.Graphics3D g) { 
        Size s = new Size(100,100); 
        Point l = new Point(g.ChartXCenter - (s.Width / 2), g.ChartYCenter - (s.Height / 2)); 
        Rectangle r = new Rectangle(l,s); 
        g.Pen.Color = Color.Aquamarine; 
        g.Brush.Color = Color.Blue; 
        g.Rectangle(r); 
}

[VB.Net]

Private Sub TChart1_AfterDraw(ByVal sender As Object, ByVal g As Steema.TeeChart.Drawing.Graphics3D) Handles TChart1.AfterDraw 
        Dim S As New Size(100, 100) 
        Dim L As New Point(g.ChartXCenter - (S.Width / 2), g.ChartYCenter - (S.Height / 2)) 
        Dim R As New Rectangle(L, S) 
        g.Pen.Color = Color.Aquamarine 
        g.Brush.Color = Color.Blue 
        g.Rectangle(R) 
End Sub

1.5.2 3D圖表

在3D圖表上，您也可以在Z平面中移動(dòng)矩形。此示例將矩形放置在左側(cè)壁上，但將其移向圖表后部的中間位置（朝向Back Wall），例：

[C#.Net]

private void Form1_Load(object sender, System.EventArgs e) { 
        point3DSeries1.LinePen.Visible = false; 
        point3DSeries1.FillSampleValues(20); 
        point3DSeries1.VertAxis = VerticalAxis.Both; 
        point3DSeries1.HorizAxis = HorizontalAxis.Both; 
        tChart1.Aspect.Chart3DPercent = 50; 
        tChart1.Axes.Depth.Visible = true; 
} 
 
private void tChart1_AfterDraw(object sender, Steema.TeeChart.Drawing.Graphics3D g) { 
        Size s = new Size(100,100); 
        Point l = new Point(tChart1.Axes.Left.Position, g.ChartYCenter - (s.Height / 2)); 
        Rectangle r = new Rectangle(l,s); 
        g.Pen.Color = Color.Aquamarine; 
        g.Brush.Color = Color.Blue; 
        g.Rectangle(r, tChart1.Aspect.Width3D/2); 
}

[VB.Net]

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
        Point3DSeries1.LinePen.Visible = False 
        Point3DSeries1.FillSampleValues(20) 
        Point3DSeries1.VertAxis = Steema.TeeChart.VerticalAxis.Both 
        Point3DSeries1.HorizAxis = Steema.TeeChart.HorizontalAxis.Both 
        TChart1.Aspect.Chart3DPercent = 50 
        TChart1.Axes.Depth.Visible = True 
End Sub 
 
Private Sub TChart1_AfterDraw(ByVal sender As Object, ByVal g As Steema.TeeChart.Drawing.Graphics3D) Handles TChart1.AfterDraw 
        Dim S As New Size(100, 100) 
        Dim L As New Point(TChart1.Axes.Left.Position, g.ChartYCenter - (S.Height / 2)) 
        Dim R As New Rectangle(L, S) 
        g.Pen.Color = Color.Aquamarine 
        g.Brush.Color = Color.Blue 
        g.Rectangle(R, TChart1.Aspect.Width3D / 2) 
End Sub

1.6 添加3D形狀

您可以將3D形狀添加到3D圖表中。此示例在Chart矩形的中間繪制一個(gè)Cube：

[C#.Net]

private void Form1_Load(object sender, System.EventArgs e) { 
        point3DSeries1.LinePen.Visible = false; 
        point3DSeries1.FillSampleValues(20); 
        tChart1.Aspect.Chart3DPercent = 50; 
        tChart1.Legend.Visible = false; 
        tChart1.Axes.Depth.Visible = true; 
} 
 
private void tChart1_AfterDraw(object sender, Steema.TeeChart.Drawing.Graphics3D g) { 
        Size s = new Size(50,50); 
        Point p = new Point(g.ChartXCenter - (s.Width/2), g.ChartYCenter - (s.Height/2)); 
        Rectangle r = new Rectangle(p,s); 
        g.Cube(r, 0, 20, true); 
}

[VB.Net]

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
        Point3DSeries1.LinePen.Visible = False 
        Point3DSeries1.FillSampleValues(20) 
        TChart1.Aspect.Chart3DPercent = 50 
        TChart1.Legend.Visible = False 
        TChart1.Axes.Depth.Visible = True 
End Sub 
 
Private Sub TChart1_AfterDraw(ByVal sender As Object, ByVal g As Steema.TeeChart.Drawing.Graphics3D) Handles TChart1.AfterDraw 
        Dim S As New Size(50, 50) 
        Dim P As New Point(g.ChartXCenter - (S.Width / 2), g.ChartYCenter - (S.Height / 2)) 
        Dim R As New Rectangle(P, S) 
        g.Cube(R, 0, 20, True) 
End Sub

1.7 添加文字

1.7.1 2D文本位置

將文本添加到最后一個(gè)矩形，示例：

[C#.Net]

private void tChart1_AfterDraw(object sender, Steema.TeeChart.Drawing.Graphics3D g) { 
        string text = "My Text"; 
        Size s = new Size(150, 50); 
        Point p = new Point(g.ChartXCenter - (s.Width/2), g.ChartYCenter - (s.Height/2)); 
        Rectangle r = new Rectangle(p,s); 
        g.Pen.Color = Color.Blue; 
        g.Rectangle(r); 
 
        g.TextOut(Convert.ToInt32(g.ChartXCenter - (g.TextWidth(text)/2)), Convert.ToInt32(g.ChartYCenter - (g.TextHeight(text)/2)), text); 
}

[VB.Net]

Private Sub TChart1_AfterDraw(ByVal sender As Object, ByVal g As Steema.TeeChart.Drawing.Graphics3D) Handles TChart1.AfterDraw 
        Dim Text As String = "My Text" 
        Dim S As New Size(50, 50) 
        Dim P As New Point(g.ChartXCenter - (S.Width / 2), g.ChartYCenter - (S.Height / 2)) 
        Dim R As New Rectangle(P, S) 
        g.Pen.Color = Color.Blue 
        g.Rectangle(R) 
 
        g.TextOut(Convert.ToInt32(g.ChartXCenter - (g.TextWidth(Text) / 2)), Convert.ToInt32(g.ChartYCenter - (g.TextHeight(Text) / 2)), Text) 
End Sub

1.7.2 3D文字位置

通過使用帶有az坐標(biāo)的TextOut重載，可以將文本放置在不同的3D平面中，例：

[C#.Net]

private void Form1_Load(object sender, System.EventArgs e) { 
        point3DSeries1.FillSampleValues(20); 
        point3DSeries1.LinePen.Visible = false; 
        tChart1.Aspect.Chart3DPercent = 50; 
} 
 
private void tChart1_AfterDraw(object sender, Steema.TeeChart.Drawing.Graphics3D g) { 
        string text = "My Text"; 
        g.TextOut(g.ChartXCenter, g.ChartYCenter, tChart1.Aspect.Width3D / 2, text); 
}

[VB.Net]

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
        Point3DSeries1.FillSampleValues(20) 
        Point3DSeries1.LinePen.Visible = False 
        TChart1.Aspect.Chart3DPercent = 50 
End Sub 
 
Private Sub TChart1_AfterDraw(ByVal sender As Object, ByVal g As Steema.TeeChart.Drawing.Graphics3D) Handles TChart1.AfterDraw 
        Dim Text As String = "My Text" 
        g.TextOut(g.ChartXCenter, g.ChartYCenter, TChart1.Aspect.Width3D / 2, Text) 
End Sub

1.8 應(yīng)用示例

此示例獲取系列的第3和第10個(gè)值，在它們之間繪制一條直線，并告訴我們新線的第一個(gè)和最后一個(gè)點(diǎn)的值以及它們之間的差異，示例：

[C#.Net]

private void Form1_Load(object sender, System.EventArgs e) { 
        tChart1.Aspect.View3D = false; 
        line1.FillSampleValues(20); 
} 
 
private void tChart1_AfterDraw(object sender, Steema.TeeChart.Drawing.Graphics3D g) { 
        if(tChart1.Series.Count > 0){ 
            if(tChart1.Series[0].Count > 10) { 
                Series s = tChart1.Series[0]; 
                int h = Convert.ToInt32(g.TextHeight("H")); 
                Point p1 = new Point(s.CalcXPos(3), s.CalcYPos(3)); 
                Point p2 = new Point(s.CalcXPos(10), s.CalcYPos(10)); 
                g.Pen.Color = Color.Blue; 
                g.Pen.Width = 2; 
                g.Pen.Style = System.Drawing.Drawing2D.DashStyle.Dash; 
                g.MoveTo(p1); 
                g.LineTo(p2, 0); 
                g.TextOut(p1.X, p1.Y - h, "Point value: " + s.YValues[3].ToString()); 
                g.TextOut(p2.X, p2.Y, "Point value: " + s.YValues[10].ToString()); 
                g.TextOut(p2.X, p2.Y + h, "Change is: " + Convert.ToString(s.YValues[3] - s.YValues[10])); 
            } 
        } 
}

[VB.Net]

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load 
        TChart1.Aspect.View3D = False 
        Line1.FillSampleValues(20) 
End Sub 
 
Private Sub TChart1_AfterDraw(ByVal sender As Object, ByVal g As Steema.TeeChart.Drawing.Graphics3D) Handles TChart1.AfterDraw 
        If TChart1.Series.Count > 0 Then 
            If TChart1.Series(0).Count > 10 Then 
                Dim S As Steema.TeeChart.Series = TChart1.Series(0) 
                Dim H As Integer = Convert.ToInt32(g.TextHeight("H")) 
                Dim P1 As New Point(S.CalcXPos(3), S.CalcYPos(3)) 
                Dim P2 As New Point(S.CalcXPos(10), S.CalcYPos(10)) 
                g.Pen.Color = Color.Blue 
                g.Pen.Width = 2 
                g.Pen.Style = System.Drawing.Drawing2D.DashStyle.Dash 
                g.MoveTo(P1) 
                g.LineTo(P2, 0) 
                g.TextOut(P1.X, P1.Y - H, "Point value: " & S.YValues(3)) 
                g.TextOut(P2.X, P2.Y, "Point value: " & S.YValues(10)) 
                g.TextOut(P2.X, P2.Y + H, "Change is: " & (S.YValues(3) - S.YValues(10))) 
            End If 
        End If 
End Sub