ASP.NET Hashtable
Hashtable object contains items with the key / value pairs expressed.
Try - Example
Create Hashtable
Hashtable object contains items with the key / value pairs expressed. Key is used as the index by search key value can be achieved on a quick search.
Add items to Hashtable through Add () method.
The following code creates a Hashtable object called mycountries, and add the four elements:
Sub Page_Load
if Not Page.IsPostBack then
dim mycountries=New Hashtable
mycountries.Add("N","Norway")
mycountries.Add("S","Sweden")
mycountries.Add("F","France")
mycountries.Add("I","Italy")
end if
end sub
</script>
Data Binding
Hashtable object can automatically generate text and values for the following controls:
- asp: RadioButtonList
- asp: CheckBoxList
- asp: DropDownList
- asp: Listbox
To bind data to a RadioButtonList control, first create a RadioButtonList control in an .aspx page (without any asp: ListItem elements):
<body>
<form runat="server">
<asp:RadioButtonList id="rb" runat="server" AutoPostBack="True" />
</form>
</body>
</html>
Then add the script to create the list, and the binding values in the list to the RadioButtonList control:
sub Page_Load
if Not Page.IsPostBack then
dim mycountries=New Hashtable
mycountries.Add("N","Norway")
mycountries.Add("S","Sweden")
mycountries.Add("F","France")
mycountries.Add("I","Italy")
rb.DataSource=mycountries
rb.DataValueField="Key"
rb.DataTextField="Value"
rb.DataBind()
end if
end sub
</script>
<html>
<body>
<form runat="server">
<asp:RadioButtonList id="rb" runat="server" AutoPostBack="True" />
</form>
</body>
</html>
Then we add a subroutine, when a user clicks on an item in the RadioButtonList control when the subroutine is executed. When a radio button is clicked, label will appear in the line of text:
Examples
sub Page_Load
if Not Page.IsPostBack then
dim mycountries=New Hashtable
mycountries.Add("N","Norway")
mycountries.Add("S","Sweden")
mycountries.Add("F","France")
mycountries.Add("I","Italy")
rb.DataSource=mycountries
rb.DataValueField="Key"
rb.DataTextField="Value"
rb.DataBind()
end if
end sub
sub displayMessage(s as Object,e As EventArgs)
lbl1.text="Your favorite country is: " & rb.SelectedItem.Text
end sub
</script>
<html>
<body>
<form runat="server">
<asp:RadioButtonList id="rb" runat="server"
AutoPostBack="True" onSelectedIndexChanged="displayMessage" />
<p><asp:label id="lbl1" runat="server" /></p>
</form>
</body>
</html>
The demonstration >>
Note: You can not choose to add to the Hashtable items are sorted.For the project alphabetical or numerical order, use the SortedList object.