ASP.NET displaying data using DataList control

The Templates are as follows:
1. ItemTemplate
2. AlternatingItemTemplate
3. EditItemTemplate
4. FooterTemplate
5. HeaderTemplate
6. SelectedItemTemplate
7. SeparatorTemplate

The following screenshot illustrates the different templates of this control.

As you can see from this fi gure, the templates are grouped under three broad categories. These are:

1. I tem Templates
1. Header and Footer Templates
2. Separator Template

Note that out of the templates given above, the ItemTemplate is the one and only mandatory template that you have to use when working with a DataList control. Here is a sample of how your DataList control's templates are arranged:

<asp:DataList id="dlEmployee" runat="server">
<HeaderTemplate>
...
</HeaderTemplate>
<ItemTemplate>
...
</ItemTemplate>
<AlternatingItemTemplate>
...
< /AlternatingItemTemplate>
<FooterTemplate>
...
</FooterTemplate>
</asp:DataList>

The following screenshot displays a DataList control populated with data and with its templates indicated.

Customizing a DataList control at run time

You can customize the DataList control at run time using the ListItemType property in the ItemCreated event of this control as follows:

private void DataList1_ItemCreated(object sender, ...........System.Web.UI.WebControls.
{
          switch (e.Item.ItemType)
          {
                  case System.Web.UI.WebControls.ListItemType.Item :
                        e.Item.BackColor = Color.Red; 
                        break;  
                  case System.Web.UI.WebControls.ListItemType. AlternatingItem :
                        e.Item.BackColor = Color.Blue;
                        break;
                  case System.Web.UI.WebControls.ListItemType. SelectedItem :
                        e.Item.BackColor = Color.Green;
                        break;
                  default :
                        break;
          }
}

The Styles that you can use with the DataList control to customize the look and feel are:

1. AlternatingItemStyle
2. EditItemStyle
3. FooterStyle
4. HeaderStyle
5. ItemStyle
6. SelectedItemStyle
7. SeparatorStyle

You can use any of these styles to format the control, that is, format the HTML code that is rendered.

You can also use layouts of the DataList control for formatting, that is, further customization of your user interface. The available layouts are as follows:

FlowLayout
TableLayout
VerticalLayout
HorizontalLayout

You can specify your desired fl ow or table format at design time by specifying the following in the .aspx file.

RepeatLayout = "Flow"

You can also do the same at run time by specifying your desired layout using the RepeatLayout property of the DataList control as shown in the following code snippet:

DataList1.RepeatLayout = RepeatLayout.Flow

In the code snippet, it is assumed that the name of the DataList control is DataList1.

Let us now understand how we can display data using the DataList control. For this, we would fi rst drag and drop a DataList control in our web form and specify the templates for displaying data. The code in the .aspx fi le is as follows:

<asp:DataList ID="DataList1" runat="server">
           <HeaderTemplate>
                <table border="1">
                    <tr>
                         <th>
                                Employee Code
                         </th>
                         <th>
                                Employee Name
                         </th>
                         <th>
                                Basic
                          </th>
                         <th>
                                Dept Code
                         </th>
                    </tr>
           </HeaderTemplate>
           <ItemTemplate>
                  <tr bgcolor="#0xbbbb">
                          <td>
                                <%# DataBinder.Eval(Container.DataItem, "EmpCode")%>
                          </td>
                          <td>
                                 <%# DataBinder.Eval(Container.DataItem, "EmpName")%>
                          </td>
                          <td>
                                  <%# DataBinder.Eval(Container.DataItem, "Basic")%>
                          </td>
                           <td>
                                   <%# DataBinder.Eval(Container.DataItem, "DeptCode")%>
                           </td>
                 </tr>
           </ItemTemplate>
           <FooterTemplate>
           </FooterTemplate>
</asp:DataList>

The DataList control is populated with data in the Page_Load event of the web form using the DataManager class as usual.

protected void Page_Load(object sender, EventArgs e)
{
            DataManager dataManager = new DataManager();          
            DataList1.DataSource = dataManager.GetEmployees();
            DataList1.DataBind();
}

Note that the DataBinder.Eval() method has been used as usual to display the values of the corresponding fi elds from the data container in the DataList control. The data container in our case is the DataSet instance that is returned by the GetEmployees () method of the DataManager class.

When you execute the application, the output is as follows: