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Old February 20th, 2006, 09:37 AM
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Default addhandler catch 22


I have an (in advance) unknown number of dropdownlists in an arraylist. I add a handler like this:

AddHandler arraylist(i).SelectedIndexChanged, AddressOf SomeDropDownList_SelectedIndexChanged

Now I want to make the following event handler:

Private Sub SomeDropDownList_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)
End Sub

Which does not work, because I have to define which dropdown it handles (!!??)

handles a_Specific_dropdown.SelectedIndexChanged.

But if I have to define which dropdown this event handles, what use is it to generate dropdowns at runtime (based on a database query)? Can't I define just one event handler, and let it handle all (new and unknown untill runtime) dropdownlists? This one is driving me crazy for a long time now... could somebody please help me?


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Old February 20th, 2006, 12:00 PM
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Hi Friend,Really interesting question.
I spent a lot of time on it.I made the code in C#.net as below.
I wrote this code in Page_Load event.If you try to write it in any other event like Button_Click...then it won't work.If I m correct,you can register an event in only page_Initialize & page_Load event.

int no;
no=5;//Any other number from database
DropDownList d;
string s;
for(int i=0;i<no;i++)
    d=new DropDownList();
    d.Items.Add(new ListItem("AA","A"));
    d.Items.Add(new ListItem("BB","B"));
    d.ID="d" + i.ToString();
    d.SelectedIndexChanged+=new EventHandler(d_SelectedIndexChanged);
private void d_SelectedIndexChanged(object sender, EventArgs e)

Give me your feedback as soon as possible

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Old February 20th, 2006, 01:01 PM
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Many thanks!!! It still does not work in page_load somehow... I just never tried to do it in Page_Init, assuming that it just didn't work. But in Page_Init it does work...

Thanks Savan!

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