Flash 8 Cookbook

14.5. Preselecting Menu Control Values

Problem

You want a Flash form to initialize with values already selected in a combo box or list.

Solution

For a combo box or single-select list, assign a value to the selectedIndex property. For a multiselect list, assign a value to the selectedIndices property.

Discussion

You can use the selectedIndex property to programmatically select a value from a combo box or list component instance. In order for that approach to work, of course, you’ll need to know the index of the item you want to select. Each item in the combo box or list has a whole number index. The first item has an index of 0, the second has an index of 1, and so on. Therefore, if you know you want to programmatically select the third item in the combo box, you need only assign the value of 2 to the selectedIndex property. For example, if you have a combo box named ccbProducts, you can programmatically select the third item with the following code:

	ccbProducts.selectedIndex = 2;

However, more often than not, you will know the value of the item you want to select rather than the index. If that occurs, you will need to use a for statement to loop through all the items of the combo box, checking each to see whether it matches the value you want to select. You can use the getItemAt() method to retrieve a combo box item of a particular index. You can use the length property to retrieve the number of items in the combo box. So with that in mind, the following code shows an example in which ...