Tutorial 49: Adding custom text or drawings to chart
« on: February 05, 2016, 01:29:39 AM »
Crossing Charts for .NET exposes 3 events that you can use to add custom content, text or drawings to the chart canvas:
 
  • BeginPaint: occurs just after clearing the canvas and before any other drawing is done.
  • AfterPaint: occurs when chart is completed, before screen refreshing occurs..
  • ValueClick: occurs when any value item (bar, line, point, ...) is clicked by user.

In this sample, a simple text is added to the chart in the left side ("Custom text added by user").

Steps:

1. Create a new Windows application project (VB.NET).
2. Add Crossing Charts Library to the toolbox pallete and drag it to Form1.
3. Copy and paste de following code:
 
Code: [Select]
Imports CrossingChartsLibrary
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
  With CrossingCharts1
    .SampleChart()
    .Style = STYLE2D3D.STYLE2D_PIE
    .RefreshChart()
  End With
End Sub
Private Sub CrossingCharts1_AfterPaint(ByVal g As CustomGraphics) Handles Super2d3dGraph1.AfterPaint
  g.RotateTransform(90)
  g.TranslateTransform(30, -50)
  ' Draw text in white first, displaced 2 pixels, to simulate a glow effect
  g.DrawString("Custom Text Added By User", New Font("Arial", 30), New SolidBrush(Color.White), 0, 0)
  g.DrawString("Custom Text Added By User", New Font("Arial", 30), New SolidBrush(Color.Purple), 2, 2)
  g.ResetTransform()
End Sub
End Class

Results:

« Last Edit: February 16, 2016, 11:20:19 AM by CrossingCharts »