BUG: Graph: ExtraData May Not Say: Invalid Property Value

- Professional Edition of Microsoft Visual Basic for Windows,

  versions 2.0 and 3.0

  system for Windows, version 1.0

SYMPTOMS

When you use the Graph custom control, the ExtraData property will not always generate an "Invalid Property Value" error when you assign it invalid numbers.

CAUSE

ExtraData has different valid ranges, depending on which GraphType you are using. The widest range is from 0 to 15, inclusive. Even if values between 0 and 15 are not within the documented range for an individual GraphType, they may not generate an error.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

If you are using the 3-D bar graph (GraphType = 4), the ExtraData property holds the color values for the sides of the bars. Color values range from 0 to 15, so the legal values for ExtraData also range from 0 to 15. If you are using the 2-D pie graph (GraphType = 1) or the 3-D pie graph (GraphType = 2), the value of ExtraData will determine whether or not a pie piece is exploded from the graph. The documented range for ExtraData with pie graphs is from 0 to 1, where 0 = False and 1 = True. In practice, however, the range for ExtraData with pie graphs is from 0 to 15, where even values equal False and odd values equal True.

Steps to Reproduce Problem

1. Start Visual Basic or from the File menu, choose New Project (ALT, F, N) if Visual Basic is already running. Form1 is created by default.

2. From the File menu, choose Add File. In the Files box, select the GRAPH.VBX custom control file. The Graph tool will appear in the toolbox.

3. Add a graph control (Graph1) to Form1.

4. In the Properties list box, set the following values and properties:

      Property    Value
      ----------------------------
   
      GraphType   2
      DrawMode    2
      NumSets     1
      NumPoints   5
      ExtraData   0, 1, 14, 15, 16
   
   

• No change when ExtraData is set to 0.
• The second data point will be exploded when ExtraData is set to 1.
• No change when ExtraData is set to 14 (even numbers less than 16 = FALSE).
• The fourth data point will be exploded when ExtraData is set to 15 (odd numbers less than 16 = TRUE).
• An "Invalid Property Value" message generated when ExtraData is set to 16.