Data Going Out of Synch when using GridView inside UpdatePanel - asp.net

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 have to fix rapidly! Can anyone help?
I have multiple UpdatePanels that have GridViews inside that can be edited by the user. There is a search feature and filter buttons that select queried data from the database and display in the GridView. There is sorting enabled and the "out of synchness" occurs mostly when sorting and then editing a field.
The data comes from a SQL Database. I can update the data directly through OnTextChange option of my TemplateField like this:
<asp:GridView
ID="GridView4"
runat="server"
OnSorting="TaskGridView_Sorting"
AllowSorting="True"
Width="100%" >
<Columns>
<asp:TemplateField SortExpression="name" HeaderText="Name">
<HeaderStyle HorizontalAlign="Left" CssClass="col_name" />
<ItemTemplate>
<asp:TextBox ID="name" AutoPostBack="True" CssClass="col_name" runat="server" Text='<%# Eval("name") %>' Width=180 OnTextChanged="text_change" />
</ItemTemplate>
</asp:TemplateField>
...
I have my gridview inside an UpdatePanel that has these options:
<asp:UpdatePanel ID="UpdatePanel1" runat="server" UpdateMode="Conditional">
<ContentTemplate>
...
I have enabled partial rendering like this:
<ajaxToolKit:ToolkitScriptManager EnablePartialRendering="true" runat="server" />
I have buttons that filter the data by requerying the database and displaying just the filtered data like this:
DataGrid_Load(DAL.Search_reg_log(OrgText.Text, searchText, searchCol), "reg");
The gridview gets its data loaded like this:
private void DataGrid_Load(DataTable command, string type)
{
DataTable dataTable = new DataTable();
dataTable = command;
string sortDir = ViewState["SortDirection"] as string;
string sortExp = ViewState["SortExpression"] as string;
if(ViewState["SortExpression"] != null)
{
dataTable = resort(dataTable, sortExp, sortDir);
}
try
{
var query = from c in dataTable.AsEnumerable()
where c.Field<string>("status") == "Invoiced" && c.Field<string>("reg_cat_id") != "Archive"
|| c.Field<string>("status") == "Confirmed" && c.Field<string>("reg_cat_id") != "Archive"
select c ;
if(query.Any()){
DataTable t2 = query.CopyToDataTable();
GridView4.DataSource = t2;
GridView4.DataBind();
} else {
GridView4.DataSource = new DataTable();
GridView4.DataBind();
}
}
catch(Exception e) {
ErrorText.Text = "Caught Exception: " + e;
}
...
I have isolated one cause of the data errors which occurs after sorting a column and then
protected void TaskGridView_Sorting(object sender, GridViewSortEventArgs e)
{
string sortExp = ViewState["SortExpression"] as string;
string sortDir = ViewState["SortDirection"] as string;
if(sortDir == "asc" & sortExp == e.SortExpression.ToString())
ViewState["SortDirection"] = "desc";
else
ViewState["SortDirection"] = "asc";
ViewState["SortExpression"] = e.SortExpression.ToString();
if(searchCol != "" && searchText != "")
DataGrid_Load(DAL.Search_reg_log(OrgText.Text, searchText, searchCol), "reg");
else
DataGrid_Load(DAL.reg_log(HeadText.Text, OrgText.Text), "reg");
UpdatePanels();
}
Here is the resort function:
public static DataTable resort(DataTable dt, string colName, string direction)
{
dt.DefaultView.Sort = colName + " " + direction;
dt = dt.DefaultView.ToTable();
return dt;
}
Please help with some direction of what might be causing this.

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);
}