Remove TemplateField during page load or before databind - asp.net

Question

I want to remove templatefield from gridview during pageload or before databind to GridView. I have 2 data sources for retrieving data. The data retrieved from one of the data sources do not have the columns ExpireDate and ExpireDays.
So I want to delete the templatefields corresponding to ExpireDate and ExpireDays if the GridView is populated from the data source that do not have those 2 fields.
Setting the visibility to false still will have error of DataRowView doesn't contain property name ExpireDate and ExpireDays.
Markup
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" OnRowCommand="GridView1_RowCommand" OnRowDataBound="GridView1_RowDataBound">
<Columns>
<asp:BoundField DataField="ID" HeaderText="No."/>
<asp:BoundField DataField="Name" HeaderText="Name"/>
<asp:BoundField DataField="CourseName" HeaderText="Course Enroll" />
<asp:BoundField DataField="SubMember" HeaderText="ChildMember" />
<asp:TemplateField HeaderText="Expiry Days">
<ItemStyle HorizontalAlign="Center" />
<ItemTemplate>
<asp:Label runat="server" ID="expDsL" Text=' <%# Eval("ExpiryDays") %>'>
</asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Expiry On">
<ItemStyle HorizontalAlign="Center" />
<ItemTemplate>
<asp:Label runat="server" ID="expDeL" Text=' <%# Eval("ExpiryDate") %>'>
</asp:Label>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Function">
<ItemStyle HorizontalAlign="Center" Width="100px"></ItemStyle>
<ItemTemplate>
<asp:ImageButton ImageUrl="~/Images/editB.gif" ID="btnEdit" runat="server" ToolTip="Edit" CommandName="Edit" CommandArgument='<%# Eval("ID") %>' />
<asp:ImageButton ImageUrl="~/Images/delB.gif" ID="btnDelete" runat="server" ToolTip="Delete" CommandName="Delete" CommandArgument='<%# Eval("ID") %>' />
</ItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
Code Behind
protected void Page_Load(object sender, EventArgs e)
{
if(Class.ToLower() != "classAA")
{
// using naveen answer can remove the column.
var expiryDateF = ((DataControlField)GridView1.Columns.Cast<DataControlField>().Where(fid => fid.HeaderText == "Expiry Days").SingleOrDefault());
var expiryDaysF = ((DataControlField)GridView1.Columns.Cast<DataControlField>().Where(fid => fid.HeaderText == "Expiry On").SingleOrDefault());
if (expiryDateF != null)
{
GridView1.Columns.Remove(expiryDateF);
}
if (expiryDaysF != null)
{
GridView1.Columns.Remove(expiryDaysF);
}
}
if(!this.IsPostBack)
{
BindData();
}
}
protected void SaveMember(object sender, EventArgs e)
{
//getting member information and perform checking.
bool success = dbbb.AddMem(memberdetails);
if(success == true)
{
BindData();
}
else
{
//prompt fail message.
}
}
protected void BindData()
{
DataTable dt = dbbb.RetrieveList();
if(dt != null)
{
GridView1.DataSource = dt;
GridView1.DataBind();
}
}
protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
if(e.Row.RowType == DataControlRowType.DataRow)
{
ImageButton btnDel = (ImageButton)e.Row.FindControl("btnDelete");
btnDel.Attributes.Add("onclick", "return confirm('Are you sure you want to delete this member?')");
}
}
How could I delete the column?

Answer 1

Two methods to achieve this
Method 1 - Remove by Index
if(!table.Columns.Contains("CustomerID1"))
{
//seven is the column index here. ie, 8th column
CustomersGrid.Columns.RemoveAt(7);
}
Method 2 - Remove using Columns Header Text
var expiryDateField= ((DataControlField)CustomersGrid.Columns
.Cast<DataControlField>()
.Where(fld => fld.HeaderText == "Expiry Date")
.SingleOrDefault());
if(expiryDateField != null)
{
CustomersGrid.Columns.Remove(expiryDateField);
}
Please not that
CustomersGrid is the name of the asp:GridView here.
table is the DataTable that acts as the DataSource of the GridView
The code should be called before DataBind of the GridView

Answer 2

Attach to the rowDataBound event of the grid, there you can set it dynamically.
You have to know the datasource name of the field you want to hide,
for example the headertext for the cell is "SomeHeader", but the databoundfield name for that cell is
"SomeOtherName"
then you have to check it like this (debug through GetColumnIndexByName) and
check the value of
((BoundField)cell.ContainingField).DataField
int GetColumnIndexByName(GridViewRow row, string columnName)
{
int columnIndex = 0;
foreach (DataControlFieldCell cell in row.Cells)
{
if (cell.ContainingField is BoundField)
if (((BoundField)cell.ContainingField).DataField.Equals(columnName))
break;
columnIndex++; // keep adding 1 while we don't have the correct name
}
return columnIndex;
}
remember that the code above will use a BoundField... then use it like:
protected void GridView_RowDataBound(object sender, GridViewRowEventArgs e)
{
if (e.Row.RowType == DataControlRowType.DataRow)
{
int index = GetColumnIndexByName(e.Row, "SomeOtherName");
string columnValue = e.Row.Cells[index].Text;
}
}