Lists
ArrayList-A collection of items containing a single data value.
Use the Add method to add items to the ArrayList
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<script runat="server"> |
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Sub Page_Load |
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if Not Page.IsPostBack then |
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dim Munsters=New ArrayList |
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Munsters.Add("Herman") |
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Munsters.Add("Lily") |
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Munsters.Add("Grandpa") |
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Munsters.Add("Eddie") |
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Munsters.Add("Marylyn") |
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end if |
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end sub |
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</script> |
An ArrayList object contains 16 entries by default.
You can resize an ArrayList with the TrimToSize() method:
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<script runat="server"> |
| 2 |
Sub Page_Load |
| 3 |
if Not Page.IsPostBack then |
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dim Munsters=New ArrayList |
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Munsters.Add("Herman") |
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Munsters.Add("Lily") |
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Munsters.Add("Grandpa") |
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Munsters.Add("Eddie") |
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Munsters.Add("Marylyn") |
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Munsters.TrimToSize() |
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end if |
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end sub |
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</script> |
You can sort an ArrayList alphabetically or numerically with Sort()
| 1 |
<script runat="server"> |
| 2 |
Sub Page_Load |
| 3 |
if Not Page.IsPostBack then |
| 4 |
dim Munsters=New ArrayList |
| 5 |
Munsters.Add("Herman") |
| 6 |
Munsters.Add("Lily") |
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Munsters.Add("Grandpa") |
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Munsters.Add("Eddie") |
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Munsters.Add("Marylyn") |
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Munsters.TrimToSize() |
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Munsters.Sort() |
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end if |
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end sub |
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</script> |
You can sort in reverse order using Reverse() after the Sort() method
| 1 |
<script runat="server"> |
| 2 |
Sub Page_Load |
| 3 |
if Not Page.IsPostBack then |
| 4 |
dim Munsters=New ArrayList |
| 5 |
Munsters.Add("Herman") |
| 6 |
Munsters.Add("Lily") |
| 7 |
Munsters.Add("Grandpa") |
| 8 |
Munsters.Add("Eddie") |
| 9 |
Munsters.Add("Marylyn") |
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Munsters.TrimToSize() |
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Munsters.Sort() |
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Munsters.Reverse() |
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end if |
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end sub |
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</script> |
List Controls
3 types
- Simple List Controls
- CheckboxList
- DropDownList
- Listbox
- RadioButtonList
- RepeaterControl
- Repeater
- ComplexListControls
- DataList
- DataGrid
Common Properties of List Controls
Property |
Description |
AutoPostBack |
Postback occurs then user changes list selection |
DataMember |
Table |
DataSource |
dataSource |
DataTextField |
Field in the dataSource to use |
DataTextFormatString |
Formatting string that controls the format of the data |
DataValueField |
What field in the data source provides the value of each list item |
Items |
Collection of items in the list control |
SelectedIndex |
Lowest index of the selected items |
SelectedItem |
Item selected with the lowest index in the list control |
Events:
OnSelectedIndexChanged
Called whenever the selection of the list control changes and is posted back to the server.