Set the background image for the header in the DataGrid and gridview

In some cases, the default style of the DataGrid or gridview cannot meet the increasing requirements of users. Many people are pursuing beautiful styles. Setting the background for the table header is also one of the following aspects. What can be done to meet this requirement? My method is as follows:
DataGrid:

Private   Void Datagrid1_itemdatabound ( Object Sender, system. Web. UI. webcontrols. datagriditemeventargs E)
{
If (E. Item. itemtype = System. Web. UI. webcontrols. listitemtype. header)
{
E. Item. Attributes. Add ( " Style " , " Background-image: url('background.gif ') " );
}
}

Gridview:

Protected   Void Gridview1_rowdatabound ( Object Sender, gridviewroweventargs E)
{
If (E. Row. rowtype = Datacontrolrowtype. header)
{
E. Row. Attributes. Add ( " Style " , " Background-image: url('background.gif ') " );
}
}