Updating gridview row is not saving the data - asp.net

Question

I am having issue when updating gridview! everything is seems to be working. but when i hit finish editing the data will not save!
but when i click edit the correct fields prompt me to enter new value but it wont save!
here is my asp
<asp:GridView ID="GridView1" runat="server" CssClass="report"
AutoGenerateColumns="False" onrowediting="GridView1_RowEditing"
DataKeyNames="TimeID" onrowupdating="GridView1_RowUpdating"
onrowcommand="GridView1_RowCommand"
onrowcancelingedit="GridView1_RowCancelingEdit">
<Columns>
<asp:BoundField DataField="date" Visible="true" ReadOnly="true" HeaderText="Date" />
<asp:BoundField DataField="Description" HeaderText="Stage Description" ReadOnly="True" />
<asp:TemplateField HeaderText="Start Time">
<ItemTemplate>
<asp:Label ID="Label7" runat="server" Text='<%# ConvertToShotTime(Eval("StartTime")) %>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="txtStartTime" ValidationGroup="1" Width="90px" class="TimeEntry" runat="server" Text='<%# ConvertToShotTime(Eval("StartTime")) %>'></asp:TextBox>
<asp:RequiredFieldValidator ID="RequiredFieldValidator6" ControlToValidate="txtStartTime" runat="server" ErrorMessage="RequiredFieldValidator"></asp:RequiredFieldValidator>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="End Time">
<ItemTemplate>
<asp:Label ID="Label1" runat="server" Text='<%# ConvertToShotTime(Eval("EndTime")) %>'></asp:Label>
</ItemTemplate>
<EditItemTemplate>
<asp:TextBox ID="txtEndTime" class="TimeEntry" ValidationGroup="1" Width="90px" runat="server" Text='<%# ConvertToShotTime(Eval("EndTime")) %>'></asp:TextBox>
<asp:RequiredFieldValidator ID="RequiredFieldValidator66" ControlToValidate="txtEndTime" runat="server" ErrorMessage="RequiredFieldValidator"></asp:RequiredFieldValidator>
</EditItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField="TimeInHours" HeaderText="Time Time (Hours)" ReadOnly="True" />
<asp:CommandField ShowEditButton="true" ShowCancelButton="true"
ButtonType="Image" EditImageUrl="~/images/edit_record.jpg"
CancelImageUrl="~/images/edit_no.jpg"
UpdateImageUrl="~/images/update_record.jpg" />
<asp:TemplateField ShowHeader="False">
<ItemTemplate>
<asp:ImageButton ID="lnbCopy" runat="server" AlternateText="Delete"
CommandName="DeleteRecord" CommandArgument='<%# Bind("TimeID") %>' OnClientClick="return confirm('Are you sure you want to delete this row?');" ImageUrl="~/images/delete_record.jpg" />
</ItemTemplate>
<EditItemTemplate>
<asp:Label ID="lblTimeID" runat="server" Text='<%# Eval("TimeID") %>'></asp:Label>
</EditItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
here is what i have done in behind code
protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e) {
GridView1.EditIndex = e.NewEditIndex;
loadTable();
}
protected void GridView1_RowCancelingEdit(object sender, GridViewCancelEditEventArgs e) {
GridView1.EditIndex = -1;
loadTable();
}
protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e) {
GridViewRow row = GridView1.Rows[e.RowIndex] as GridViewRow;
var StartTime = row.FindControl("txtStartTime") as TextBox;
var EndTime = row.FindControl("txtEndTime") as TextBox;
var id = row.FindControl("lblTimeID") as Label;
SqlConnection conn = new SqlConnection(conStr.GetConnectionString("myServer1"));
SqlCommand comm = new SqlCommand();
comm.CommandText = "UPDATE CDSTimeSheet SET StartTime = #StartTime, EndTime = #EndTime ,timeElapsed = datediff(minute,#startTime , #EndTime), timeInSeconds = datediff(second,#startTime , #EndTime) WHERE TimeID = #id";
comm.Connection = conn;
comm.Parameters.AddWithValue("#id", id.Text);
comm.Parameters.AddWithValue("#StartTime", StartTime.Text);
comm.Parameters.AddWithValue("#EndTime", EndTime.Text);
conn.Open();
comm.ExecuteNonQuery();
conn.Close();
GridView1.EditIndex = -1;
loadTable();
}
what am i doing wrong?

Answer 1

It sounds a lot like you are not calling DataBind on your grid after updating the underlying data. After you perform the update (possibly within the loadTable method that I see referenced up there), call
GridView1.DataBind();
That should refresh the data in the grid.
After your comments, I see that you're not using the NewValues collection in the GridViewUpdateEventArgs parameter to get the actual incoming, updated field values. Try this:
String StartTime = e.NewValues["StartTime"].ToString();
String EndTime = e.NewValues["EndTime"].ToString();
String id = e.Keys[0].ToString();
Note that these variables are strings now, not TextBoxs, so you don't need to add ".Text" on them when you add them as parameters.

Answer 2

Handle the postback, basically if you fill the grid view in each postback you are re filling the gridview with old data, that's why you retrieve data with no changes (remember after Update button this trigger a postback). So, in case this is your case, try this.
if(!this.IsPostback)
{
(Method that fills your GridView)
}