How to Clear the Legend Information from a Graph Control

- Professional Edition of Microsoft Visual Basic for Windows, version 3.0

SUMMARY

The Graph Control is one of the most versatile of the custom controls included with Visual Basic Professional, but it is also complex and can be difficult to master. It is easy to add legends using the LegendText property, but removing legends is not at all intuitive. It is necessary to set the DataReset property to 5 to clear the legend information.

MORE INFORMATION

The following example demonstrates how switching a graph between different numbers of sets produces an anomalous result when the DataReset property is not used.

Steps to Reproduce Behavior

1. Start a new project in Visual Basic. Form1 is created by default.

2. Add a graph control (Graph1) and 2 command buttons (Command1 and Command2) to Form1. Be sure to make the Graph control large enough to accommodate the legend

3. Add the following code to the Command1_Click and Command2_Click event procedures of Form1:

      Sub Command1_Click ()
         ' Remove the apostrophe from following line to remove the legend:
         ' graph1.DataReset = 5
         graph1.ThisPoint = 1
         graph1.LegendText = "1992"
         graph1.ThisPoint = 2
         graph1.LegendText = ""
         graph1.NumSets = 1
         graph1.DrawMode = 2
      End Sub
   
      Sub Command2_Click ()
         graph1.LegendText = "1992"
         graph1.NumSets = 2
         graph1.ThisPoint = 2
         graph1.LegendText = "1993"
         graph1.DrawMode = 2
      End Sub
   
   

4. Run the application by choosing Start from the Run menu or by pressing the F5 key.

REFERENCES

This article is based on the following articles in the Microsoft Knowledge Base:

ARTICLE-ID: Q81999

TITLE     : BUG: Graph: AutoInc Increments ThisPoint Instead of ThisSet

TITLE     : VB Graph Control: ThisPoint, ThisSet Reset to 1 at Run Time

TITLE     : Set DrawMode to 2 Or 3 to Update Changes to Graph at Run Time