Raise custom event with

**kt_sc** · 10:17 AM

I have a full custom server control with javascript embedded.

In short it will list out images and when an image is selected, it will be displayed as the first image at the top. And this top image can be collapsed and expanded when clicked.

I am very confused how to raise a custom event when an image is clicked. And how to return two string arguments to the client via the event arguments of the event (index number of the item selected, and a short description of item).

A snippet from RenderContents. Will post the rest of the code upon request.

Code:

   Protected Overrides Sub RenderContents(ByVal output As HtmlTextWriter)
        output.WriteLine("<script language=javascript>                          ")
        output.WriteLine("function CollapseExpand() {                              ")
        output.WriteLine("var div = document.getElementById(div01);    ")
        output.WriteLine("if (div.style.display != 'none') {                         ")
        output.WriteLine("div.style.display = 'none';                                 ")
        output.WriteLine("} else {                                                              ")
        output.WriteLine("div.style.display = '';                                         ") ' or = block
        output.WriteLine(" }}                                                                      ")

        'output.WriteLine("var top;                                                              ")
        'output.WriteLine("function SetDefault(i) {                                      ")
        'output.WriteLine("var img = document.getElementById(i);            ")
        'output.WriteLine("if (img.src != top.src') {                                      ")
        'output.WriteLine("img.src = 'none';                                                 ")
        'output.WriteLine("} else {                                                                ")
        'output.WriteLine("div.style.display = '';                                          ") ' or = block
        'output.WriteLine(" }                                                                         ")

        output.WriteLine("}</script>                                                       ")

        'image at the top
        output.AddAttribute(HtmlTextWriterAttribute.Src, TopImageUrl)
        output.AddAttribute(HtmlTextWriterAttribute.Onclick, "CollapseExpand()")
        output.RenderBeginTag(HtmlTextWriterTag.Img)
        output.RenderEndTag() 'end img

        output.AddStyleAttribute(HtmlTextWriterStyle.Top, "100")
        output.AddStyleAttribute(HtmlTextWriterStyle.Left, "100")
        output.AddStyleAttribute(HtmlTextWriterStyle.Width, "100")
        output.AddStyleAttribute(HtmlTextWriterStyle.Height, "500")
        output.AddStyleAttribute(HtmlTextWriterStyle.Padding, "5")
        output.AddStyleAttribute(HtmlTextWriterStyle.Overflow, "hidden") ' for scrollbar use "auto"
        output.AddStyleAttribute(HtmlTextWriterStyle.Display, "none")
        output.AddAttribute("id", "div01")
        output.RenderBeginTag(HtmlTextWriterTag.Div)

        'add the remaining images
        Dim item As Object
        Dim i As Byte
        For Each item In imageurl
            output.WriteLine("<br>")
            output.AddAttribute(HtmlTextWriterAttribute.Src, imageurl.Item(i))
            'output.AddAttribute("Onmouseover", "Inform()")
            'output.AddAttribute("Onmouseout", "UnInform()")
            'output.AddAttribute(HtmlTextWriterAttribute.Onclick, "SetDefault(this)")
            'output.AddAttribute(HtmlTextWriterAttribute.Id, i.ToString)
            output.RenderBeginTag(HtmlTextWriterTag.Img)
            output.RenderEndTag() 'end img

            i += 1

            'Dim s1 As New SelectEventArgs
            's1.ItemNoArg = i
            's1.DescArg = imagedescription.Item(i)
            'Me.TopImageUrl = imageurl.Item(i)
            'OnSelectedChanged(s1)

        Next

        output.RenderEndTag() 'end div
    End Sub

Thanks for viewing. And would appreciate any help.