Question

Here is what I am doing. I create two buttons in a header row of a gridview that i created. The buttons are +page and -page. When -page is hit I remove the paging and all the data goes down the page and -page disappears and +page is there.

Here comes my issue When I hit +page I must be double postbacking because one row of my data disappears. I will provide the code below. What can i do to fix this??

Dim bttnrempag As New Button
    bttnrempag.ID = "bttnrempag"
    bttnrempag.Text = "      Paging"
    bttnrempag.CssClass = "bttnMinEG"
    bttnrempag.ValidationGroup = "alone"
    bttnrempag.Attributes.Add("onclick", "return Paging('1')")

    Dim bttnallowpag As New Button
    bttnallowpag.ID = "bttnallowpag"
    bttnallowpag.Text = "      Paging"
    bttnallowpag.ValidationGroup = "alone"
    bttnallowpag.CssClass = "bttnAddEG"
    bttnallowpag.Attributes.Add("onclick", "return Paging('0')")

---------------------How the buttons are added------------------------------------------

    Dim row As New GridViewRow(-1, -1, DataControlRowType.Separator, DataControlRowState.Normal)
    row.Cells.Add(cell)
    cell.Controls.Add(bttnrempag) '36
    cell.Controls.Add(bttnallowpag)

----------------------------------------------------------------------------------------

function Paging(remove) {
    var gridView = $get('<%=Gridview1.ClientID %>');
    var txt2 = $get('<%=TextBox2.ClientID %>');
    if (remove == '1') {
        txt2.value = '1';
        __doPostBack('<%=UpdatePanel1.ClientID %>', '');
        return false;
    }
    else {
        txt2.value = '0';
        __doPostBack('<%=UpdatePanel1.ClientID %>', '');
        return false;
    }

Edited

<asp:UpdatePanel ID="UpdatePanel1" runat="server">
    <ContentTemplate >
        <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
        <asp:GridView ID="GridView1" runat="server" AllowPaging="True" 
            AutoGenerateColumns="False" BackColor="White" BorderColor="#E7E7FF" 
            BorderStyle="None" BorderWidth="1px" CellPadding="3" 
            DataSourceID="SqlDataSource1" Font-Names="Comic Sans MS" Font-Size="XX-Small"
            Caption = '<table border="" width="100%" cellpadding="3" cellspacing="0" bgcolor="#4A3C8C"><tr><td style = "font-size:X-large;font-family:Arial CE;color:White"><b>Ordering/Receiving Log</u></td></tr></table>' 
            Font-Bold="True" PageSize="15" >
            <RowStyle BackColor="#E7E7FF" ForeColor="#4A3C8C" />

            <Columns>
                      Bound Data
            </Columns>
            <FooterStyle BackColor="#B5C7DE" ForeColor="#4A3C8C" />
            <PagerStyle BackColor="#E7E7FF" ForeColor="#4A3C8C" HorizontalAlign="Right" />
            <EmptyDataTemplate>
            <head>
                <meta http-equiv="refresh" content="5;URL=/Corporate_newpo/ReceivingLog.aspx?">
            </head>
                <script type="text/javascript" >
                    var count = 6;
                    var counter = setInterval("timer()", 1000); //1000 will  run it every 1 second

                    function timer() {
                        count = count - 1;
                        if (count <= 0) {
                            clearInterval(counter);
                            //counter ended, do something here
                            return;
                        }
                        $get("timer").innerHTML = "The Table will Reload in " + count + " secs";
                    }
                </script>
                <asp:Label ID="Label1" runat="server" Font-Bold="True" Font-Size="Large" 
                    ForeColor="#993333" Text="No Data was Found for the Selected Filter"></asp:Label><br /><br />
               <span id="timer" style="font-size:medium;color:blue"></span>
            </EmptyDataTemplate>
            <SelectedRowStyle BackColor="#738A9C" Font-Bold="True" ForeColor="#F7F7F7" />
            <HeaderStyle BackColor="#4A3C8C" Font-Bold="True" ForeColor="#F7F7F7" />
            <AlternatingRowStyle BackColor="#F7F7F7" />
            <PagerTemplate>
                <small 12px""="" style="font-size:xx-small; padding-right">Go To Page</small>
                <asp:DropDownList ID="ddlPageSelector" runat="server" AutoPostBack="true" 
                    Font-Size="XX-Small" Height="19px" Width="36px">
                </asp:DropDownList>
                <asp:ImageButton ID="btnFirst" runat="server" CommandArgument="First" 
                    CommandName="Page" SkinID="pagefirst" />
                <asp:ImageButton ID="btnPrevious" runat="server" CommandArgument="Prev" 
                    CommandName="Page" SkinID="pageprev" />
                <asp:ImageButton ID="btnNext" runat="server" CommandArgument="Next" 
                    CommandName="Page" SkinID="pagenext" />
                <asp:ImageButton ID="btnLast" runat="server" CommandArgument="Last" 
                    CommandName="Page" SkinID="pagelast" />
            </PagerTemplate>
            </asp:GridView>
        </ContentTemplate> 
    </asp:UpdatePanel>

So as you can see, when one or the other is hit I set a textbox to some value then i do a partial postback to my Gridview which is in that Updatepanel.

Was it helpful?

Solution

I've found a nice solution that works great. It does append it's own handler, but I guess that can be fixed too.

using System.Linq;

private void GridView_OnItemDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        var buttons = e.Row.Cells.OfType<DataControlFieldCell>().SelectMany(item => item.Controls.OfType<ImageButton>());
        foreach (ImageButton imageButton in buttons)
        {
            var argument = imageButton.CommandName + "$" + imageButton.CommandArgument;
            imageButton.OnClientClick = this.Page.ClientScript.GetPostBackClientHyperlink(this.GridView, argument) + "; return false;";
        }
    }
}

OTHER TIPS

I suspect it's because you called the "__doPostBack" method. The buttons' normal default click behaviour will perform the Async postback, you probably made it perform another time. Try removing it and see how it goes.

Can you try to put the Click Attribute on the buttons in RowDataBound event declaration??

Cheers.

Try changing your <asp:ImageButtons> to be regular HTML <img> tags.

I've run into this sort of thing before which was hard to diagnose and even harder to explain. See here and here for some buggy behavior that might help. If you have <img> tags with blank src attributes, then the hyperlinks I provided likely explain the problem. If you do not have any blank <img> tags then keep reading for my work around.

In my specific case, it was only happening on some servers (at some client sites) but not others, so I couldn't find any concrete issues with the code. My workaround was to change my <asp:ImageButtons> to regular <img> tags with javascript click events that would call a function to perform the postback, much like your Paging() function.

For some reason, I have found that an <asp:ImageButton> with a client side onclick event of return:confirm('are you sure?'); will stop a postback if the confirm() returns false, however returning false the way you do in your Paging() function after manually calling a __doPostBack does not consistently stop the page from posting back a second time.

Please look at the html as it is rendered on the page:

Every time it's present 

<img src=""/>

double postback can happen, for some browser...

This trouble could be resolved setting a default, blank, image for every button

<asp:ImageButton ImageUrl="~/Images/blank.gif"...>

Anyway, this command can be entered in Immediate Window if you put a breakpoint inside Page_Load and allow you to indentify the control that caused postback

Page.Request.Params["__EVENTTARGET"];

Try this, (I don't know why you were using javascript):

bttnrempag.onclick += bttnrempag_Click; 

protected void bttnrempag_Click(object sender, EventArgs e)
{
    //handle the removal of paging or whatever.
}

You have to provide an image for your ImageButtons. Otherwise the HTML rendered will produce an <img src=""> tag and when this is rendered, it will cause a postback. Try it.

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