Data Going Out of Synch when using GridView inside UpdatePanel

Question

Data in my GridView inside an UpdatePanel is going out of synch with the database and I can\'t figure out why. This has resulted in incorrect updates to the database which I hav

Answer 1

It looks like you are having some trouble with GridView and updating them. I will post a complete working example below. Start with that and gradually update that code to fit your own needs, like getting data with var query = from c in dataTable.AsEnumerable(). The important thing is to sort the data every time you (re)bind the GridView data. And I'm not sure what is happening inside resort, but you have to use dt.DefaultView.ToTable(); to save the sorting in the DataTable.

<asp:UpdatePanel ID="UpdatePanel1" runat="server">
    <ContentTemplate>

        <asp:GridView ID="GridView1" runat="server"
            DataKeyNames="ID" AllowSorting="true" 
            OnSorting="GridView1_Sorting"
            AutoGenerateColumns="false" 
            AutoGenerateEditButton="true"
            OnRowEditing="GridView1_RowEditing"
            OnRowCancelingEdit="GridView1_RowCancelingEdit"
            OnRowUpdating="GridView1_RowUpdating">
            <Columns>

                <asp:TemplateField HeaderText="ID" SortExpression="ID">
                    <ItemTemplate>
                        <%# Eval("ID") %>
                    </ItemTemplate>
                </asp:TemplateField>

                <asp:TemplateField HeaderText="Name" SortExpression="name">
                    <ItemTemplate>
                        <%# Eval("name") %>
                    </ItemTemplate>
                    <EditItemTemplate>
                        <asp:TextBox ID="TextBox1" runat="server" Text=' <%# Eval("name") %>'></asp:TextBox>
                    </EditItemTemplate>
                </asp:TemplateField>

            </Columns>
        </asp:GridView>

        <asp:Literal ID="Literal1" runat="server"></asp:Literal>

    </ContentTemplate>
</asp:UpdatePanel>

Code behind

protected void Page_Load(object sender, EventArgs e)
{
    //bind data in an ispostback check
    if (!IsPostBack)
    {
        DataGrid_Load();
    }
}


private void DataGrid_Load()
{
    //load the datatable data
    DataTable dt = source;

    //check if the viewsstate existst
    if (ViewState["SortExpression"] != null && ViewState["SortDirection"] != null)
    {
        //sort the datatable before binding it to the gridview
        dt.DefaultView.Sort = ViewState["SortExpression"] + " " + ViewState["SortDirection"];
        dt.DefaultView.ToTable();
    }

    //bind the sorted datatable to the gridvidw
    GridView1.DataSource = dt;
    GridView1.DataBind();
}


protected void GridView1_Sorting(object sender, GridViewSortEventArgs e)
{
    //load the previous sorting settigns
    string sortExp = ViewState["SortExpression"] as string;
    string sortDir = ViewState["SortDirection"] as string;

    //reverse the direction if the column is the same as the previous sort
    if (sortDir == "asc" & sortExp == e.SortExpression.ToString())
        ViewState["SortDirection"] = "desc";
    else
        ViewState["SortDirection"] = "asc";

    //put the current sort column in the viewstate
    ViewState["SortExpression"] = e.SortExpression.ToString();

    //rebind data
    DataGrid_Load();
}


protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
{
    //set the edit index and rebind data
    GridView1.EditIndex = e.NewEditIndex;
    DataGrid_Load();
}


protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e)
{
    //reset the edit index and rebind data
    GridView1.EditIndex = -1;
    DataGrid_Load();
}


protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
    //use findcontrol to locate the textbox in the edit template
    TextBox tb = (TextBox)GridView1.Rows[e.RowIndex].FindControl("TextBox1");

    //get the id of the row from the datakeys
    int id = Convert.ToInt32(GridView1.DataKeys[e.RowIndex].Values[0]);

    //show result for testing
    Literal1.Text = "ID: " + id + "<br>Name: " + tb.Text;

    //reset the edit index and rebind data
    GridView1_RowCancelingEdit(null, null);
}