Hi makumbi,
For clearing the TextBox value you need to set the TextBox value with empty string inside the OnTextChanged event.
C#
protected void Score_TextChanged(object sender, EventArgs e)
{
GridViewRow row = (sender as TextBox).NamingContainer as GridViewRow;
hfRowIndex.Value = row.RowIndex.ToString();
(sender as TextBox).Text = string.Empty;
}
VB.Net
Protected Sub Score_TextChanged(ByVal sender As Object, ByVal e As EventArgs)
Dim row As GridViewRow = TryCast(TryCast(sender, TextBox).NamingContainer, GridViewRow)
hfRowIndex.Value = row.RowIndex.ToString()
TryCast(sender, TextBox).Text = String.Empty
End Sub