[RESOLVED] Access to datagridview to datagridwiew to chart : almost there?

[Blitz690620]

Hi,

I have an access database with two tables:

Table 1 holds equipment information (various columns)
Table 2 holds counter information for these equipments (running hours)

In my VB Form, I have a datagridview1 which shows the data from table 1 (the datasource is a bindingsource to a dataset)
I have a second datagridview2 which shows all the hour counter records for the selected equipment from table 1 (the datasource is bindingsource to another bindingsource here).

So far, everything works...

I placed a chart on the form, where the datasource is TableEquipmentTableCounterBindingSource.
The chart/series/datasource/XValueMember and YValueMembers are set to the columns I want to display, but the chart remains empty...

When I run it, and select another equipment in datagridview1, the second datagridview displays the appropriate hour counters for that equipment, bet the chart stays empty at all times...

Any Ideas?

[IanRyder]

Hi,

I bet you have forgotten to either set the DataSource of the Chart or call the Series.Invalidate Method to redraw your Chart when your values change? Here is a typical chart setup:-

With chtTotalOrders
  With .ChartAreas(0)
    .AxisX.Interval = 2
    .AxisX.LabelStyle.Interval = 1
    .Area3DStyle.Enable3D = True
  End With
  With .Series(0)
    .ChartType = DataVisualization.Charting.SeriesChartType.Column
    .XValueType = DataVisualization.Charting.ChartValueType.Date
    .XValueMember = "OrderDate"
    .YValueMembers = "TotalOrders"
    .LegendText = "Total Orders Received"
  End With
  .Legends(0).Docking = DataVisualization.Charting.Docking.Top
End With

And here is a typical chart redraw when values change:-

With chtTotalOrders
  .DataSource = currentAnalysis
  .Series.Invalidate()
End With

Hope that helps.

Cheers,

Ian

[Blitz690620]

Hi Ian,

thank you for your reply to my post.

After starting this thread , I googled some more on this topic, and found out I had to call the DataBind method before updating the chart.

Chart1.DataBind()
        Chart1.Update()

This solved the problem. I was curious and tried your solution also, but that didn't work:

Chart1.Series.Invalidate()
        Chart1.Update()

Am I doing it wrong? What does "Invalidate" do? I would expect there would also exist a "validate", but that doesn't seem to be the case...

[IanRyder]

Hi,

Glad you got it sorted. I have never actually had a DataBind issue but I have come across a Chart not Redrawing when required and the Invalidate Method causes a Redraw of the Graphics of the Chart. Have a look here:-

Chart.Invalidate Method

Cheers,

Ian