Protected Sub DropDownList2_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles DropDownList2.SelectedIndexChanged
MsgBox("OK")
If (DropDownList2.SelectedIndex) = 1 Then
ListBox1.Visible = True
End If
End Sub
I am facing problem in above code. I want to make listbox visible when the value of dropdownlist get changed. Does any one know that?
Dropdown's SelectedIndexChange will fire every time you select a different item. But you are making the ListBox visible only when SelectedIndex =1. Remove the SelectedIndex condition like this:
Protected Sub DropDownList2_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles DropDownList2.SelectedIndexChanged
'MsgBox("OK")
ListBox1.Visible = True
End Sub
And ListBox will be visible each time DropDown selection changes.
BTW: It is not clear how you are setting visibility of the listbox to false. Uou can post some markup and code to make it clear.
You can use the following code to get the listbox to appear on ANY change in the value of the dropdownlist
Protected Sub DropDownList2_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles DropDownList2.SelectedIndexChanged
Dim cs As ClientScriptManager = Page.ClientScript
cs.RegisterClientScriptBlock(Me.GetType(), "MyScript", "<script type=""text/javascript""> Alert("Ok"); </script>", False);
ListBox1.Visible = True
End Sub
However if you want to change when the user selects the first/second or nth item, you can use this
Protected Sub DropDownList2_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles DropDownList2.SelectedIndexChanged
Dim cs As ClientScriptManager = Page.ClientScript
cs.RegisterClientScriptBlock(Me.GetType(), "MyScript", "<script type=""text/javascript""> Alert("Ok"); </script>", False);
if DropDownList2.SelectedIndex = 0 //makes the listbox visible only when you select the first item, Use 1 for making the list box visible on the selection of the second item, so on and so forth.
ListBox1.Visible = True
end if
End Sub
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.