Hiding Columns in Gridview when grid view is empty - asp.net

Question

I have a grid view on which i am hiding some columns. it gives me expected result when there is at least one item in grid view but when my grid is empty then it shows hidden columns. what to do how to solve it when there is no record means grid view is empty then it also hides the columns that has been made hidden i am hiding columns in OnitemDataBound(object sender, GridItemEventArgs e) event of grid.

Answer 1

Put the Hidden column data in DatakeysName property of Gridview. Then it will not show any column. You can get that for further use. If you want to show no data found message, then set EmptyDataText="No Data Found!!!".

Answer 2

Assuming that if there is no data coming from the server you want to hide the column names or something like that. You can use empty template feature of grid view. Go to the designer mode click quick property of grid view. Go to the templates and select the empty template. Then write some text or message like "No record found." and run the code. You do not need to write any server side code for this.

Answer 3

The Column should be made hidden using the code.
1. The logic should be such that we loop through the rows and see if the column does not have values for all the rows.
2. if the value does not exist for the column only then make the column hidden.
3. this entire logic should be implemented in prerender event.
I can provide you sample code tonight...
here is the sample code...
protected void GridView1_PreRender(object sender, EventArgs e)
{
bool isColumnEmpty = true;
int columnIndex =2;
for (int i = 0; i < GridView1.Rows.Count; i++)
{
if (GridView1.Rows[i].Cells[columnIndex].ToString() != string.Empty)
{
isColumnEmpty = false;
break;
}
}
if (isColumnEmpty)
{
GridView1.Columns[columnIndex].Visible = false;
}
}
Full Code Sample
ASPX Code :
<form id="form1" runat="server">
<div>
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
onprerender="GridView1_PreRender">
<Columns>
<asp:BoundField DataField="dc1" HeaderText="Column - 1" />
<asp:BoundField DataField="dc2" HeaderText="Column - 2" />
<asp:BoundField DataField="dc3" HeaderText="Column - 3" />
<asp:BoundField DataField="dc4" HeaderText="Column - 4" />
<asp:BoundField DataField="dc5" HeaderText="Column - 5" />
</Columns>
</asp:GridView>
</div>
</form>
CS Code :
public partial class Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
GridView1.DataSource = GetDataSet();
GridView1.DataBind();
}
private DataSet GetDataSet()
{
DataSet ds = new DataSet();
DataTable dt = new DataTable();
DataColumn dc1 = new DataColumn("dc1");
DataColumn dc2 = new DataColumn("dc2");
DataColumn dc3 = new DataColumn("dc3");
DataColumn dc4 = new DataColumn("dc4");
DataColumn dc5 = new DataColumn("dc5");
dt.Columns.Add(dc1);
dt.Columns.Add(dc2);
dt.Columns.Add(dc3);
dt.Columns.Add(dc4);
dt.Columns.Add(dc5);
for (int i = 0; i < 10; i++)
{
DataRow dr = dt.NewRow();
dr[dc1] = i;
//dr[dc2] = "2" + i.ToString();
dr[dc3] = "3"+ i.ToString();
dr[dc4] = "4" + i.ToString();
dr[dc5] = "5" + i.ToString();
dt.Rows.Add(dr);
}
ds.Tables.Add(dt);
return ds;
}
protected void GridView1_PreRender(object sender, EventArgs e)
{
bool isColumnEmpty = true;
int columnIndex =2;
for (int i = 0; i < GridView1.Rows.Count; i++)
{
if (GridView1.Rows[i].Cells[columnIndex].ToString() != string.Empty)
{
isColumnEmpty = false;
break;
}
}
if (isColumnEmpty)
{
GridView1.Columns[columnIndex].Visible = false;
}
}
}