How to hide columns in an ASP.NET GridView with auto-generated columns?

GridView1.Columns.Count is always zero even SqlDataSource1.DataBind();

But Grid is ok

I can do

for (int i = 0; i < GridView1.HeaderRow.Cells.Count;i++)

I rename request headers here but

GridView1.Columns[i].Visible = false;

I can't use it because of GridView1.Columns.Count is 0.

So how can I hide them ?

Solution 1:

Try putting the e.Row.Cells[0].Visible = false; inside the RowCreated event of your grid.

protected void bla_RowCreated(object sender, GridViewRowEventArgs e)
{
    e.Row.Cells[0].Visible = false; // hides the first column
}

This way it auto-hides the whole column.

You don't have access to the generated columns through grid.Columns[i] in your gridview's DataBound event.

Solution 2:

The Columns collection is only populated when AutoGenerateColumns=false, and you manually generate the columns yourself.

A nice work-around for this is to dynamically populate the Columns collection yourself, before setting the DataSource property and calling DataBind().

I have a function that manually adds the columns based on the contents of the DataTable that I want to display. Once I have done that (and then set the DataSource and called DataBind(), I can use the Columns collection and the Count value is correct, and I can turn the column visibility on and off as I initially wanted to.

static void AddColumnsToGridView(GridView gv, DataTable table)
{
    foreach (DataColumn column in table.Columns)
    {
        BoundField field = new BoundField();
        field.DataField = column.ColumnName;
        field.HeaderText = column.ColumnName;
        gv.Columns.Add(field);
    }
}

Solution 3:

Note: This solution only works if your GridView columns are known ahead of time.

It sounds like you're using a GridView with AutoGenerateColumns=true, which is the default. I recommend setting AutoGenerateColumns=false and adding the columns manually:

<asp:GridView runat="server" ID="MyGridView"
    AutoGenerateColumns="false" DataSourceID="MySqlDataSource">
    <Columns>
        <asp:BoundField DataField="Column1" />
        <asp:BoundField DataField="Column2" />
        <asp:BoundField DataField="Column3" />
    </Columns>
</asp:GridView>

And only include a BoundField for each field that you want to be displayed. This will give you the most flexibility in terms of how the data gets displayed.