drop down list

  • Thread starter Thread starter JP.Gantlin
  • Start date Start date
J

JP.Gantlin

I have a drop down list that pulls the names of States from a database.

To this list I want to add "All", so the page will search all states.

how do I combine the manually-added "All" with the list of states from the
database?


Also how would i parse that so the sql string uses * or something

thanks
 
I have a drop down list that pulls the names of States from a database.

To this list I want to add "All", so the page will search all states.

how do I combine the manually-added "All" with the list of states from the
database?
Click to expand...

You need the Items.Insert method of the DropDownList to add a new ListItem
at the index you specify...
 
at what point? Page load?

if i do that it loads "all" over and over with each page load
if i use this , it never laods it:



If Not IsPostBack Then

DropDownList2.Items.Insert(1, "All")

End If
 
at what point? Page load?
Click to expand...

No - you should populate DropDownLists in Page_Init

DropDownList2.Items.Clear
DropDownList2.DataSource = <dataource>
DropDownList2.Items.Insert(1, "All")
 
Well that works on DropDownList1 (countries) *but* DropDownList2 (states)
no longer works

DropDownList2 pulls its data based on what is selected in DropDownList1 .


What do you think?



DropDownList1.Items.Clear()

DropDownList1.DataSource = SqlDataSource1

DropDownList1.DataBind()

DropDownList1.Items.Insert(0, "All")

DropDownList2.Items.Clear()

DropDownList2.DataSource = SqlDataSource2

DropDownList2.DataBind()

DropDownList2.Items.Insert(0, "All")
 
Well that works on DropDownList1 (countries) *but* DropDownList2 (states)
no longer works

DropDownList2 pulls its data based on what is selected in DropDownList1 .
Click to expand...
What do you think?

DropDownList1.Items.Clear()
DropDownList1.DataSource = SqlDataSource1
DropDownList1.DataBind()
DropDownList1.Items.Insert(0, "All")
DropDownList2.Items.Clear()
DropDownList2.DataSource = SqlDataSource2
DropDownList2.DataBind()
DropDownList2.Items.Insert(0, "All")
Click to expand...

Well obviously not!

If the Items collection of the second DropDownList is dependent on the
selected item of the first, then you have three choices:

1) In Page_Init, query all the possible options for DropDownList2 and pump
them into a client-side JavaScript array. Then, when the selectedIndex of
DropDownList1 changes, repopulate DropDownList2 appropriately through
client-side JavaScript. Bigger hit when the page is loaded initially, but
avoids subsequent postbacks...

2) Wire up an OnSelectionChanged server-side event for DropDownList1, set
its AutoPostBack property to true, and requery the contents of DropDownList2
server-side. Much smaller initial hit, but will need a postback every time
the selectedIndex of DropDownList changes.

3) Use Ajax. Sort of a combination of the first two options...
 
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