asp.net event handler when click on link button dynamically

Question

hello everyone i just start programming in asp.net i struggling to add event handler dynamically. here is the scenario when the aspx page is load a link button is add with an event handler

page load add link button and event handler with link button

Dim products As New LinkButton

products.Text = "Products"

testPanel.Controls.Add(products)

AddHandler products.Click, AddressOf getProducts

the getProducts function will loop in the database get all the product

    Dim testDb As New Product
    Dim arr As ArrayList = testDb.DbLoop()
    Dim ObjList As ProductBo
    Dim ID As Integer
    Dim link As LinkButton



    For Each ObjtList In arr

        ID= ObjtList.C_Id
        link = New LinkButton
        testPanel.Controls.Add(New LiteralControl("<br />"))
        link.ID = ID
        link.Text = ObjList.Name
        link.CommandArgument = CustInt
        Me.testPanel.Controls.Add(link)
        AddHandler link.Click, AddressOf getProductsDetails
    Next ObjList

HERE IS MY problem after looping it will display a list of product in the database, what i want to do add a link of each product name when i click on one product it should invoke another event handler i try this one but it not working.

AddHandler link.Click, AddressOf getProductsDetails

thank you

score 3 · Answer 1 · answered Jun 08 '11 at 15:09

Don't forget you must re-create all dynamic controls on postback

Your Page is just a class remember and it is instantiated once per request, if it doesn't recreate these controls as well as the associated handlers on the postback request then you won't get anything happen..

You need to recreate these controls prior to Page_Load, you can do this in Page_Init or override the CreateChildControls method.

score 2 · Answer 2 · answered Jun 08 '11 at 15:06

2

The reason it is not working is you are going through a postback. You have to re-add your handler on every postback. I would do it on the page _Init event.

answered Jun 08 '11 at 15:06

Robert Beaubien

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score 1 · Answer 3 · answered Jun 08 '11 at 15:04

1

Interchange the following line:

Me.testPanel.Controls.Add(link)
AddHandler link.Click, AddressOf getProductsDetails

They should be:

AddHandler link.Click, AddressOf getProductsDetails
Me.testPanel.Controls.Add(link)

answered Jun 08 '11 at 15:04

Hasan Fahim

3,875
1
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score 0 · Answer 4 · edited May 25 '16 at 04:09

0

Try this:

Protected Sub page_init(ByVal sender As Object, ByVal e As System.EventArgs)  Handles Me.Init 'addhadler must in here!
    somecode...
End Sub

edited May 25 '16 at 04:09

Senjuti Mahapatra

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answered May 25 '16 at 03:24

Liyibin

1

score 0 · Answer 5 · edited May 25 '16 at 04:06

   Protected Sub page_init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init 
    addButton()'必须加在此处，否则动态注册的事件无法初始化
End Sub

Public sub addButton(ByVal nvrid As Integer) As Object
'.....
        AddHandler btn.Command, AddressOf testCmd
End sub
    Private Sub testCmd(source As Object, e As CommandEventArgs)
        Debug.Print(e.ToString)

End Sub

asp.net event handler when click on link button dynamically

5 Answers5

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