Edit visibility of a cell in GridView based on a value in the row

Question

I'm trying to set a my delete button visibility to true when the value of the last cell in row is equal to the session value which is the userID

Girdview UPDATED:

<Columns>
<asp:TemplateField>
    <ItemTemplate>
        <%# Container.DataItemIndex + 1 %>
    </ItemTemplate>
</asp:TemplateField>
<asp:BoundField DataField="attachID" HeaderText="Attachment ID" SortExpression="atID" HeaderStyle-CssClass="hidcol" ItemStyle-CssClass="hidcol"/>
<asp:BoundField DataField="attachmentTitle" HeaderText="Attachment Title" SortExpression="attachmentTitle" />
<asp:BoundField DataField="attachmentType" HeaderText="Attachment Type" SortExpression="attachmentType" />
<asp:BoundField DataField="attachmentDescription" HeaderText="Attachment Description" SortExpression="attachmentDescription" />
<asp:BoundField DataField="attachmentDate" HeaderText="Attachment Date" SortExpression="attachmentDate" />
<asp:TemplateField>
    <ItemTemplate>
        <asp:LinkButton ID="LinkButton1" runat="server" CommandName="download"  CommandArgument='<%# Eval("attachmentFile") %>'><img src="CSS/images/download.png" alt="Download File" /></asp:LinkButton>
    </ItemTemplate>
</asp:TemplateField>
<asp:TemplateField ShowHeader="False">
    <ItemTemplate>
       <asp:ImageButton ID="ImageButton1" runat="server" CausesValidation="False" CommandArgument='<%# Eval("userID") %>' CommandName="Delete" ImageUrl="~/CSS/images/delete_page.png" Text="Delete" />
    </ItemTemplate>
</asp:TemplateField>
</Columns>

I'm trying to set the Delete button property visibile if the userID machates the session["username"]

I'm not sure this is the right way or not.

Code-Behind UPDATED:

String searchValue = "" + Session["username"];

    foreach (GridViewRow row in GridView1.Rows)
    {
        // Only look in data rows
        if (row.RowType == DataControlRowType.DataRow ||
            row.RowType == DataControlRowType.EmptyDataRow)
        {
            // Find the delete button by ID
            ImageButton theDeleteButton = row.FindControl("ImageButton1") as ImageButton;

            // Verify the button was found before we try to use it
            if (theDeleteButton != null)
            {
                if (theDeleteButton.CommandArgument != searchValue)
                {
                    // Make the button invisible
                    theDeleteButton.Visible = false;
                }
            }

        }
    }

How can i make it happen ?

thanks in advance!

The Code has been Updated

Answer 1

I recommend using a TemplateField for the delete button with a CommandName attribute (similar to what you are doing with the download link button) rather than a CommandField , because it will make your code for hiding the delete button cleaner, like this:

Markup:

<asp:TemplateField>
    <ItemTemplate>
        <asp:Button ID="ButtonDelete" runat="server" CommandName="delete"  
                    CommandArgument='<%# Eval("id") %>' Text="Delete" />
    </ItemTemplate>
</asp:TemplateField>

Code-behind:

foreach (GridViewRow row in GridView1.Rows)
{
    // Only look in data rows
    if (row.RowType == DataControlRowType.DataRow || 
        row.RowType == DataControlRowType.EmptyDataRow)
    {
        // Find the delete button by ID
        Button theDeleteButton = row.FindControl("ButtonDelete") as Button;

        // Verify the button was found before we try to use it
        if(theDeleteButton != null)
        {
            // Make the button invisible
            theDeleteButton.Visible = false;
        }
    }
}

Note: The as operator will return null if the attempted cast cannot be completed successfully; hence the check for null against theDeleteButton variable.