I am now stuck. After spending ages trying to maintain dynamically added linkbutton or label to a gridview it seems I am overwriting a checkbox state on post back.
As stated I am dynamically adding either a linkbutton or a label to a place holder in a gridview with the following:
protected void LedgerGrid_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
int index = e.Row.RowIndex;
if (items[index].noteID > 0)
{
PlaceHolder label = (PlaceHolder)e.Row.FindControl("HasPrevious");
LinkButton link = new LinkButton();
link.CommandName = "LinkCommand";
link.Command += new CommandEventHandler(link_Command);
link.Text = "Yes";
link.ID = index.ToString();
label.Controls.Add(link);
}
else
{
PlaceHolder label = (PlaceHolder)e.Row.FindControl("HasPrevious");
Label noNote = new Label();
noNote.Text = "No";
label.Controls.Add(noNote);
}
Here is the gridview:
<asp:GridView runat="server" ID="LedgerGrid" AutoGenerateColumns="false"
onselectedindexchanged="LedgerGrid_SelectedIndexChanged"
onrowdatabound="LedgerGrid_RowDataBound" onrowcommand="LedgerGrid_RowCommand"
>
<Columns>
<asp:TemplateField HeaderText="Notes">
<ItemTemplate>
<asp:PlaceHolder ID="HasPrevious" runat="server"></asp:PlaceHolder>
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField HeaderText="Invoice Date" DataField="invoicedate" DataFormatString="{0:d}" />
<asp:BoundField HeaderText="Invoice" DataField="invoice" />
<asp:BoundField HeaderText="Fee Debt" DataField="Fee_Debt" DataFormatString="{0:C}" />
<asp:BoundField HeaderText="Cost Debt" DataField="Cost_Debt" DataFormatString="{0:C}" />
<asp:BoundField HeaderText="VAT Debt" DataField="VAT_Debt" DataFormatString="{0:C}" />
<asp:BoundField HeaderText="Total Debt" DataField="Total_Debt" DataFormatString="{0:C}" />
<asp:BoundField HeaderText="Client Code" DataField="ClientCode" />
<asp:ButtonField HeaderText="Matter Number" DataTextField="matternumber" CommandName="ViewMatter" />
<asp:BoundField HeaderText="Decription" DataField="matterdescription" />
<asp:TemplateField>
<ItemTemplate>
<asp:CheckBox ID="AddInvoiceCheck" runat="server" Enabled="true" />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
To make sure that my link button command works I am rebuilding the gridview as I would in the Page_load. Here is the page load:
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
string clientCode = Server.HtmlEncode(Request.QueryString["clientcode"]);
items = DataAccess.DataAccess.GetLedgerDetails(clientCode);
ViewState["LedgerItems"] = items;
ViewState["clientcode"] = clientCode;
LedgerGrid.DataSource = items;
LedgerGrid.DataBind();
LedgerClientObject clientDetails = DataAccess.DataAccess.GetClientDetails(clientCode);
ClientCodeLabel.Text = string.Format("Group Code: {0}", clientDetails.GroupCode);
ClientNameLabel.Text = string.Format("Client Name: {0}", clientDetails.ClientName);
ClientCodeFilter.DataSource = clientDetails.ClientCodes;
ClientCodeFilter.DataBind();
}
}
To maintain the dynamically added controls on post back I am calling the following:
protected void Page_PreLoad(object sender, EventArgs e)
{
if (IsPostBack)
{
items = (List<LedgerItem>)ViewState["LedgerItems"];
LedgerGrid.DataSource = items;
LedgerGrid.DataBind();
}
}
Of course it now seems that by using this method I am overwriting the state of the check-box gridview column. Am I approaching this all wrong? I would like to be able to use the viewstate to maintain the set up of my dynamically added controls to the gridview. Is there a way I can access the state of the checkbox control form gridview before/after I reload the gridview in PreLoad event?
I am checking the state of my checkbox column with a button click as follows:
protected void Unnamed1_Click(object sender, EventArgs e)
{
NoteModel note = new NoteModel();
for (int i = 0; i < LedgerGrid.Rows.Count; i++)
{
int invoice = Convert.ToInt32(LedgerGrid.Rows[i].Cells[2].Text);
CheckBox check = (CheckBox)LedgerGrid.Rows[i].FindControl("AddInvoiceCheck");
if (check.Checked)
{
note.invoices.Add(invoice);
}
}
if (note.invoices == null)
{
string clientcode = (string)ViewState["clientcode"];
ViewState["InvoiceError"] = 1;
Response.Redirect(string.Format("Ledger.aspx?clientcode={0}", clientcode));
}
else
{
string clientcode = (string)ViewState["clientcode"];
Session["NoteObject"] = note;
Response.Redirect(string.Format("AddNote.aspx?cc={0}", clientcode));
}
}
Whenever I iterate over the checkbox controls in the gridview they are all unchecked e.g overwritten by my PreLoad code!!!
In the end I decided not to use dynamically created controls. Instead I added a buttonfield to the grid view. In my rowdatabound event I then set the visibility of the button to false if it does meet my criteria. This way view state is maintained as i do not need to create control on post back.
Seems with webforms that avoiding dynamic controls where possible is the best bet. I would still like to know which event to tap into to override viewstate re-instating controls?