Call javascript function in Code Behind asp.net 3.5

I been trying to call a javascript function to validate if a checkbox at least was selected on a asp.net form, problem is that by calling directly on the printbutton, it throws and error, (print button is inside a item template of a listview control)...   So this is the current workaround I am trying but I cannot get to call the script.....please help!


Protected Sub ListView1_ItemDataBound(ByVal sender As Object, ByVal e As ListViewItemEventArgs)
        If e.Item.ItemType = ListViewItemType.DataItem Then
            Dim myButtonPrintOut1 As Button = CType(e.Item.FindControl("printButton1"), Button)
            myButtonPrintOut1.Attributes.Add("onClientClick", "checkboxChecked()")
            myButtonPrintOut1.OnClientClick = "javascript:return confirm('You wish to do this?'"
            myButtonPrintOut1.OnClientClick = "checkboxChecked()"
        End If
    End Sub

Open in new window

LVL 9
TonyRebaAsked:
Who is Participating?
 
Rajkumar GsConnect With a Mentor Software EngineerCommented:
Try this code
Protected Sub ListView1_ItemDataBound(ByVal sender As Object, ByVal e As ListViewItemEventArgs)
        If e.Item.ItemType = ListViewItemType.DataItem Then
            Dim myButtonPrintOut1 As Button = CType(e.Item.FindControl("printButton1"), Button)
            myButtonPrintOut1.Attributes.Add("onClientClick", "checkboxChecked()")
            myButtonPrintOut1.OnClientClick = "javascript:return confirm('You wish to do this?');"
            myButtonPrintOut1.OnClientClick = "checkboxChecked()"
        End If
    End Sub

Open in new window

0
 
Rajkumar GsSoftware EngineerCommented:
Changed
myButtonPrintOut1.OnClientClick = "javascript:return confirm('You wish to do this?'"

Open in new window

to
myButtonPrintOut1.OnClientClick = "javascript:return confirm('You wish to do this?');"

Open in new window


Raj
0
 
Rajkumar GsSoftware EngineerCommented:
Ignore my first post - http:#34997397

Raj
0
Get expert help—faster!

Need expert help—fast? Use the Help Bell for personalized assistance getting answers to your important questions.

 
sindhuxyzCommented:
Easy way

DropDownList1.Attributes.Add("onchange","CallBack();");
0
 
sindhuxyzCommented:
Method 2

JavaScript

<head runat="server">
    <title>Call JavaScript From CodeBehind</title>
    <script type="text/javascript">
        function alertMe() {
            alert('Hello');
        }
    </script>
</head>



C#

protected void Page_Load(object sender, EventArgs e)
{
    if (!ClientScript.IsStartupScriptRegistered("alert"))
    {
        Page.ClientScript.RegisterStartupScript(this.GetType(),
            "alert", "alertMe();", true);
    }
}
0
 
TonyRebaAuthor Commented:
sindhuxyz:


This has to be done on the Button Click event , not at the page load,  I tried using registerstartupscripts, and function was called, but, at load event... so it needs to be on button click or itemDataBound Events?

does it makes sense
0
 
TonyRebaAuthor Commented:
this is more of the code behind code I have
' First we create the function for Listview1 

    Protected Sub ListView1_ItemCommand(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.ListViewCommandEventArgs) Handles ListView1.ItemCommand

        Dim myButtonPrint1 As Button = CType(ListView1.FindControl("printButton1"), Button)


        If e.CommandSource Is myButtonPrint1 Then


            Dim recordsId As New List(Of String)
            For Each lvi1 As ListViewItem In ListView1.Items
                Dim chb1 As CheckBox = IIf(lvi1.FindControl("CheckBoxPrintProvider1") Is Nothing, IIf(lvi1.FindControl("CheckBoxPrintProvider3") Is Nothing, lvi1.FindControl("CheckBoxPrintProvider4"), lvi1.FindControl("CheckBoxPrintProvider3")), lvi1.FindControl("CheckBoxPrintProvider1"))

                If chb1.Checked = True Then
                    Dim param1 As String
                    param1 = DirectCast(lvi1.FindControl("lblId1"), Label).Text
                    ' This is the list you will save in Session object
                    'param1 = CType(e.Item.DataItem, System.Data.DataRowView)("ID").ToString()
                    recordsId.Add(param1)

                End If
            Next

            ' Store in session to be pulled out in the Printable Page
            Session("Records") = recordsId
            Response.Redirect("PrintableProviderList.aspx")
        End If
    End Sub


    Protected Sub ListView2_ItemCommand(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.ListViewCommandEventArgs) Handles ListView2.ItemCommand

        Dim myButtonPrint2 As Button = CType(ListView2.FindControl("printButton2"), Button)


        If e.CommandSource Is myButtonPrint2 Then
            Dim recordsId As New List(Of String)
            For Each lvi2 As ListViewItem In ListView2.Items
                Dim chb2 As CheckBox = IIf(lvi2.FindControl("CheckBoxPrintProvider2") Is Nothing, IIf(lvi2.FindControl("CheckBoxPrintProvider3") Is Nothing, lvi2.FindControl("CheckBoxPrintProvider4"), lvi2.FindControl("CheckBoxPrintProvider3")), lvi2.FindControl("CheckBoxPrintProvider2"))

                If chb2.Checked = True Then
                    Dim param1 As String
                    param1 = DirectCast(lvi2.FindControl("lblId2"), Label).Text
                    ' This is the list you will save in Session object
                    'param1 = CType(e.Item.DataItem, System.Data.DataRowView)("ID").ToString()
                    recordsId.Add(param1)

                End If
            Next

            ' Store in session to be pulled out in the Printable Page
            Session("Records") = recordsId
            Response.Redirect("PrintableProviderList.aspx")
        End If
    End Sub

    Protected Sub ListView1_ItemDataBound(ByVal sender As Object, ByVal e As ListViewItemEventArgs)
        If e.Item.ItemType = ListViewItemType.DataItem Then
            Dim myButtonPrintOut1 As Button = CType(e.Item.FindControl("printButton1"), Button)
            myButtonPrintOut1.Attributes.Add("onClientClick", "checkboxChecked()")
            myButtonPrintOut1.OnClientClick = "javascript:return confirm('You wish to do this?');"

            myButtonPrintOut1.OnClientClick = "checkboxChecked()"
        End If
    End Sub


 

    Protected Sub ListView2_ItemDataBound(ByVal sender As Object, ByVal e As ListViewItemEventArgs)
        If e.Item.ItemType = ListViewItemType.DataItem Then
            Dim myButtonPrintOut2 As Button = CType(e.Item.FindControl("printButton2"), Button)
            myButtonPrintOut2.Attributes.Add("onClientClick", "checkboxChecked()")

        End If
    End Sub

Open in new window

0
 
sindhuxyzCommented:
For button, you can use:

Button1.Attributes.Add("onclick","CallBack();");
0
 
TonyRebaAuthor Commented:
what does CallBack does?
0
 
TonyRebaAuthor Commented:
Dont I need to tell the name of the javascript? , in which event fo I set this?
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.