How To Update a Graph in a Form

MORE INFORMATION

To update a graph in previous versions of FoxPro, you may have used the DO UPDATEGRPH IN GENGRAPH.APP WITH command. Microsoft Visual FoxPro does not include Gengraph.app, so a new approach must be taken.

Step-by-Step Example

1. Open or switch to Microsoft Visual FoxPro, and create a new table called Mydata.dbf that contains a character field called Myseries and three numeric fields called Mydata1, Mydata2 and Mydata3.
2. Add five records to the table that contain random numbers between 1 and 20 in the three numeric fields and 'Series 1', 'Series 2', 'Series 3', and so on in the character field.
3. Create a new form called Myform, and add the table Mydata to the data environment of the form.
4. Add a grid to the form. Use the Property window to set the RecordSource property of the grid to Mydata. Leave the RecordSourceType set to Alias.
5. With the Mydata table open in the active work area, type the following command in the Command window:

      DO (_GENGRAPH) WITH "MYDATA"
   							

   This will start the Graph Wizard, so you can create the initial graph for the form. Add the three numeric fields to the Data Series list box and the character field to the Axis field of the wizard. Click the Next button, and follow the instructions provided by the wizard. Save the graph as Mygraph.dbf when prompted. In Visual FoxPro 6.0, by default a graph is saved to a form. In step 4 of the wizard, choose the option button that that says "Save graph to a table."
6. Add the Mygraph.dbf table to the data environment of the form.
7. Add an OLE Bound control to the form. Using the Property window, set the ControlSource of the OLE Bound control to MYGRAPH.OLEGRAPH, and set the Stretch property of the OLE Bound control to Isometric.
8. Add a command button to the form, and change its Caption property to Update. Place the following code in the command button's Click event procedure:

      SELECT * FROM MYDATA INTO CURSOR MYCURSOR
      TAB = CHR(09)
      CRLF = CHR(13) + CHR(10)
      SELECT MYCURSOR
      NEWDATA = TAB + "Label A" + TAB + " Label B " + TAB ;
      + " Label C " + CRLF
      SCAN
           NEWDATA = NEWDATA + MYSERIES + TAB + STR(MYDATA1) + TAB ;
           + STR(MYDATA2) + TAB + STR(MYDATA3) + CRLF
      ENDSCAN
      SELECT MYGRAPH
      APPEND GENERAL Mygraph.Olegraph DATA NEWDATA
      THISFORM.REFRESH
   							

9. Save and run the form. Make some changes to the data in the grid, and click the Update button. Note that the changes made to the grid are reflected in the graph.