MIS 3200 – Unit 4.2

1. MIS 3200 – Unit 4.2 ListItem controls CheckBoxList ListBox

2. An Index is a Position Number • This device holds up to 300 CD’s • An individual CD is found by itslocation, or position, in the device • Location/position is the number of the slot where the CD is found • This number is an index • The CD player has • properties (width, height, display, etc) and • methods (play a CD, move to another CD, etc) This is a 100 DVD video disk player

3. More ASP.NET Controls • ASP.NET Controls that hold other controls may allow the user to select one or more options at a time • CheckBoxList • Shows each item with a checkbox • The user may select any number of items • May be formatted several different ways as shown here

4. More Controls ListBox(basically the same as a CheckBoxList) • Displays items in a box (instead of checkboxes) • Box size and the existence of a scroll bar are controlled by the designer (the only difference) • Consecutive items selected by clicking on the first item and shift-clicking on the second • Non-consecutive items selected by clicking on the first item and then control-clicking on the others (control+command buttonson a Mac)

5. CheckBoxList & ListBox • Each item in these Controls is represented by a ListItem. Each ListItem has a • Value • Text • ListItems can be created and edited from the Controls properties or its smart menu

6. ListItem Collection Editor This Editor allows you to • Add or Remove items • Change the order of items • Enter/Edit the Text and Value of the item • Pre-select an item by setting Selected to True 4 2 3 1

7. ListItem Collection ListItems is a Collection -- a group of related things • You can find a specific item in the Collection using an Index • The first item in the Collection has an index value of zero, • the second one is one, • the third is two, etc. (this is called zero-based addressing) • The ListItem collection is called Items • and the index appears between [ ] like this • cblMenu.Items[0] • // this is the first item in the collection • clbMenu.Items[intMyCounter] • // this uses a variable, intMyCounter, to indicate the item

8. ListItem Collection Given the following ListItems in a CheckBoxList (cblMenu): Testing a condition for the 4th item in the CheckBoxList: if (cblMenu.Items[3].Selected) //is the 4th checkbox selected? {//the 4th checkbox has an index of 3, since the first checkbox starts at 0 //this would make “.Selected” to True lblText.Text = cblMenu.Items[3].Text; // would be Cheeseburger lblValue.Text = cblMenu.Items[3].Value; // would be ? } Assume that the Value assigned to each Text item has a price in dollars increasing by 1 starting with Green Salad for 1 and ending with Diet Pepsi at 8

9. ListItem Collection • To reset (un-check) all of the checked boxes: • cblMenu.SelectedIndex = -1;

10. Unit 4 L2.2 • In this exercise you will repeat the Unit 4.1 L2 and add a CheckBoxList • You can do this exercise using the same page you created for your L1 & L2 • To make sure things will work properly here, make sure • the L1 validators and button are in a ValidationGroup of L1, • the L2 validators and button are in a ValidationGroup set to L2, • and the L2.2 validators and button are in a ValidationGroup set to L2.2

11. L2.2 #2 • Create a new paragraph after L1 output label • Grab a Horizontal Rule from the HTML tab of the toolbox and drop it in the new paragraph • Create a new paragraph, type CheckBoxList and make it an H3 heading • Below the heading create a line that looks identical to the Total Sales line from L1 but with different names for the text box and the validators • Below that line type State of Residence

12. L2.2 #3 • Drag a RadioButtonList from the Standard tab of the toolbox and drop it after the word Residence • A RadioButtonList provides a set of mutually exclusive choices, choices where only one thing can be true (use the SelectedValue property to get the value) • Name the RadioButtonListrblState2 • Change its RepeatDirection to Horizontal • Change its RepeatLayout to Flow • Click on Items and open the ListItemCollection Editor • Add five items (same as your L2) • The first should have Text and Value = OH • The second should have Text and Value = WV • The remaining items should be PA, KY and IN

13. L2.2 #4 • Add a button below the state list • Give it an appropriate name • Change its Text to Calculate sales tax and total • Add a label named lblOutputCheckBoxList below the button • Double click on the button to create a method • Copy the code for your existing L2 Calculate button method into this new method (update code to reference L22 controls) • Add appropriate comments to the method (these first 11 steps are just like your L2) • Add a new paragraph below the RadioButtonList with the text: Check all fees that apply:

14. L2.2 #5 • Add a CheckBoxList with an appropriate name under this new paragraph with the following Text and Value properties set (see slides 5 & 6 for examples): • Value: 5.00Text: Registration Fee • Value: 7.50Text: Vehicle License Fee • Value: 12.50Text: Weight Fee • Value: 4.50Text: County/District Fees • Value: 10.00Text: Owner Responsibility Fee (see http://cob.ohio.edu/mis3200/asppub - U4L22 for an example)

15. L2.2 #5 • Using an if statement, test each checkbox by using its index value (see slide 8 for an example). If the box is checked, add (accumulate) the Value of the checked item to a decimal variable to keep track of the sum of the fees. For example, something like this (but for each index, 0 through 4): • Add a new line with the text: Fees (after sales tax)to the output label that displays how much is owed for the fees and then add this to the total amount due (see Unit 4 L2.2)

16. L2.2 #6 • Cleanup: clear the textbox, reset the radiobuttonlistand checkboxlist, set the focus to the L2.2 textbox. Make sure you add a required field validator for the radiobuttonlist(they do not work for checkboxlists, so you do not need to add one for that control) • Add the link to the L2.2 on your MIS3200 page and submit your MIS Portfolio public URL

17. Think About It! • When would a CheckBoxList be more appropriate than a ListBox (or visa versa)? • Do you foresee problems with processing a CheckBoxList (or ListBox) by using nothing more than an if statement?