How To Use the BoundTo Property to Store Numeric Values

• Microsoft Visual FoxPro for Windows, version 5.0

SUMMARY

In Visual FoxPro 3.0, when the ControlSource property of a combo box or list box evaluates to a numeric value, the ControlSource property stores the index number (position) in the list instead of the actual numeric value that is displayed. However, a new property named BoundTo has been introduced in Visual FoxPro 5.0 to solve this problem.

MORE INFORMATION

The RowSource property of a combo box or list box specifies the source of the values; that is, it indicates where the data is coming from.

The ControlSource property of a combo box specifies the data that is modified when a selection is made. It indicates where the data is going to.

When a combo box or a list box is bound to a ControlSource property with character data type, the character value is stored to the ControlSource property as it shows in the list. However, if it is bound to a ControlSource property with numeric data, the numeric value stores differently, depending on the setting of the BoundTo property. Below is a step-by-step example that shows you how to store the actual numeric value to the ControlSource property of a combo box or a list box:

1. Create a new form.

2. On the View menu, click Data Environment, then add the \Samples\Data\Orditems table to the DataEnvironment object.

3. Add a combo box control to the new form, then set combo box properties as follows:

         RowSource = 10,20,30,40,50,60,70,80,90,100
         RowSourceType = 1-Value
         ControlSource = orditems.quantity
         BoundTo = .T.
   

4. Save and Run the form.

However, if you set the BoundTo property to .F., the index number (position) of the list is stored to the quantity field instead.