Listbox Checkboxes by Erick Tejkowsi 05-30-03 Printer Version

Someone on the REALbasic NUG email lists today wanted to know how to use checkboxes in a Listbox control. To help him out, this week's tutorial will show you how to display checkboxes in a listbox and how to find out if a particular checkbox is checked or not.

Build the Interface
Fire up REALbasic and add a Listbox, an Editfield, and a Pushbutton to Window1. You can arrange the interface however you want, but mine looks like this: (note - the Listbox is on top)

Add the Code
The code for this example looks like most Listbox code, with a few exceptions. First, we'll designate our Listbox as having three columns that display headings. Then, we need to assign a type to each column using the columnType property. There are a few choices:

• 0 - default
• 1 - text
• 2 - checkbox
• 3 - editable text

//set up the listbox columns and headings me.columncount = 3 me.hasheading = TRUE me.heading(0) = "On/Off" me.heading(1) = "Name" me.heading(2) = "Skill" //set the type for each column me.columnType(0) = 2//checkbox me.columnType(1) = 1//text me.columnType(2) = 3//editable text //populate Listbox1 me.addrow "" me.cellCheck(me.lastIndex,0) = FALSE me.cell(me.lastIndex,1)="Erick" me.cell(me.lastIndex,2)="Rope tricks" me.addrow "" me.cellCheck(me.lastIndex,0) = TRUE me.cell(me.lastIndex,1)="Michael" me.cell(me.lastIndex,2)="Cooking 'possum" me.addrow "" me.cellCheck(me.lastIndex,0) = FALSE me.cell(me.lastIndex,1)="Dan" me.cell(me.lastIndex,2)="Fire-eating" me.addrow "" me.cellCheck(me.lastIndex,0) = TRUE me.cell(me.lastIndex,1)="Cletus" me.cell(me.lastIndex,2)="Long distance hopping" me.addrow "" me.cellCheck(me.lastIndex,0) = FALSE me.cell(me.lastIndex,1)="Jeremy" me.cell(me.lastIndex,2)="Yugo car repair"

To find out if a checkbox is checked or not, all you have to do is look at the Boolean value of cellCheck. Place the following code in the Action event of PushButton1. It loops through each row in the Listbox and grabs that row's name column if its checkbox is checked.

dim i as integer //clear the editfield editfield1.text="" //loop through items in listbox1 //and look for rows that are checked for i=0 to listBox1.listcount-1 if listBox1.cellCheck(i,0) then editfield1.text=editfield1.text+listBox1.cell(i,1)+chr(13) end if next

That's all there is to it. Run the project and click some of the chechboxes in the Listbox. Then, click the Pushbutton to see what happens. Simple, eh? Here's what the final result looks like:

Conclusion
You can download the code for this week's project here. See you next week!