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Using CommandArgument to find the database table record_id for a datagrid row

nateraaaa
Expert 100+
P: 663
While working on a recent project I discovered how useful the CommandArgument property can be. I needed to determine the record_id of a row displayed in my datagrid. When the user clicked the Edit ImageButton I needed to redirect the user to the Edit page where the data on the page would be prepopulated with data from the database. I tried several things without success then discovered that the CommandArgument property could be used for this task.

Here is my datagrid
[HTML]<asp:datagrid id="dgReorgs" runat="server" OnSortCommand="dgReorgs_SortCommand" OnPageIndexChanged="dgReorgs_PageIndexChanged"
PagerStyle-HorizontalAlign="Center" PagerStyle-Mode="NumericPages" BorderWidth="0px" CellSpacing="1" CellPadding="2" AllowSorting="True" ShowFooter="True" AutoGenerateColumns="False" PageSize="20"
AllowPaging="True" OnItemCommand="dgReorgs_ItemCommand" PagerStyle-CssClass="PagingLink">
<Columns>
<asp:TemplateColumn>
<HeaderStyle HorizontalAlign="Center"></HeaderStyle>
<ItemStyle HorizontalAlign="Center"></ItemStyle>
<HeaderTemplate>
<asp:ImageButton ID="ibtnAdd" Runat="server" ImageUrl="images/Add.gif" OnClick="ibtnAdd_Click" Visible="False"></asp:ImageButton>
</HeaderTemplate>
<ItemTemplate>
<asp:ImageButton ID="ibtnEdit" Visible="False" Runat="server" ImageUrl="images/Edit.gif" CommandArgument='<%# DataBinder.Eval(Container,"DataItem.record_id")%>' CommandName="Edit">
</asp:ImageButton>&nbsp;
</ItemTemplate>
</asp:TemplateColumn>
<asp:BoundColumn DataField="offer_posting_date" SortExpression="offer_posting_date" HeaderText="Offer Posting Date"
DataFormatString="{0:MM/dd/yyyy}" HeaderStyle-Font-Size="10">
<HeaderStyle HorizontalAlign="Center" ForeColor="White" BackColor="Navy"></HeaderStyle>
<ItemStyle HorizontalAlign="Center" BackColor="White"></ItemStyle>
</asp:BoundColumn>
<asp:BoundColumn DataField="symbol" SortExpression="symbol" HeaderText="Symbol" HeaderStyle-Font-Size="10">
<HeaderStyle HorizontalAlign="Center" ForeColor="White" BackColor="Navy"></HeaderStyle>
<ItemStyle HorizontalAlign="Center" BackColor="White"></ItemStyle>
</asp:BoundColumn>
<asp:BoundColumn DataField="offer_expiration_date" SortExpression="offer_expiration_date" HeaderText="Expiration Date"
DataFormatString="{0:MM/dd/yyyy}" HeaderStyle-Font-Size="10">
<HeaderStyle HorizontalAlign="Center" ForeColor="White" BackColor="Navy"></HeaderStyle>
<ItemStyle HorizontalAlign="Center" BackColor="White"></ItemStyle>
</asp:BoundColumn>
<asp:BoundColumn DataField="notes" SortExpression="notes" HeaderText="Notes" HeaderStyle-Font-Size="10">
<HeaderStyle HorizontalAlign="Center" ForeColor="White" BackColor="Navy"></HeaderStyle>
<ItemStyle Width="180px" BackColor="White" Wrap="True"></ItemStyle>
</asp:BoundColumn>
</Columns>
<PagerStyle HorizontalAlign="Center" Mode="NumericPages"></PagerStyle>
</asp:datagrid>[/HTML]

The following statement is the key CommandArgument='<%# DataBinder.Eval(Container,"DataItem.record_id")%>' (see line 12 in the code). NOTE: This statement will not work if the datasource of your datagrid does not contain a record_id column.

Now in the code behind.
I use the ItemCommand event of the datagrid to get the record_id of the row that has been selected for editing. In this event I have to check to see if the Item is part of the datagrid header section or if it is part of the datagrid pager section. If it is not then I can redirect the page to the Edit page and append the record_id as a querystring using e.CommandArgument.
Expand|Select|Wrap|Line Numbers
  1. public void dgReorgs_ItemCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
  2. {
  3. if(e.Item.ItemType != ListItemType.Header && e.Item.ItemType != ListItemType.Pager)
  4. {
  5. if(e.CommandName == "Edit")
  6. {
  7. Response.Redirect("EditReorg.aspx?value=" + e.CommandArgument);
  8. }
  9. }
  10. }
Then in the page_load event of the Edit page I will call a query that will get me the data for this row and then prepopulate the controls on the page with data.

I hope this code will help some of you understand how to use the CommandArgument property.

Nathan
Jun 11 '07 #1
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1 Comment


P: 2
it's super.but i need gridview coding.u know the coding post me.
Feb 16 '08 #2