Mobile Web Development in ASP.NET - Part 3

Introduction


The Part3 of the series on Mobile Web Development deals with the SelectionList control that offers you variety of choices of selecting an item or items from a list and act accordingly.

SelectionList Control


The SelectionList control provides the UI selection capability for a list control. Although they are both lists, a SelectionList control differs in capabilities and scope from a List control.

Features of SelectionList


An item selected from a SelectionList control does not generate a server event. You need to add a Command Control for submitting the form to the server.
SelectionList control allows multiple items to be selected.
SelectionList control manages only small lists and does not offer pagination.
SelectionList control supports different types with the SelectType attribute values: SelectType=DropDown|ListBox|Radio|MultiSelectListBox|CheckBox

The following controls can contain one or more SelectionList controls.

System.Web.UI.MobileControls.Form

System.Web.UI.MobileControls.Panel


The SelectionList control can contain one or more of the following control.

System.Web.UI.MobileControls.Item


Device Templates


The SelectionList control does not support device templates.

Example3


The following example shows how to create a selection list for hardware peripherals. When the user chooses a device, a second page displays the device name and its price.




<%@ Page Inherits="System.Web.UI.MobileControls.MobilePage"
Language="c#" %>
<%@ Register TagPrefix="mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>




For pricing, select a component:










Get the price!



Hardware Device Price Request






Example4


In this example, the DataSource property of the SelectionList class is an array called channels that is created and filled during the initial page load. You can set the SelectType property in the code and display the selection through two alternate means during postbacks



<%@ Page Inherits="System.Web.UI.MobileControls.MobilePage"
Language="c#" %>
<%@ Register TagPrefix="mobile"
Namespace="System.Web.UI.MobileControls"
Assembly="System.Web.Mobile" %>












Both the List and SelectionList controls allow you to list items from a data source and provides the following properties:

DataMember="dataMember"
DataTextField="DataTextField"
DataValueField="DataValueField"
OnItemDataBind="itemDataBindHandler"

Example5





The following example shows a SelectionList control bound to a dataset that has rows from the Authors table. On selecting an item (AuthorId), user pushes the command button to display his name in a label control.

private void Form1_Load(object sender, System.EventArgs e)
{
if (Page.IsPostBack == false)
{
oleDbDataAdapter1.Fill (dataSet21);
SelectionList1.DataSource = dataSet21;
SelectionList1.DataBind();
}
}

private void Command1_Click(object sender, System.EventArgs e)
{
Label1.Text = "Name of the selected Author is: " + SelectionList1.Items[SelectionList1.SelectedIndex].Value.ToString();
}




Get Author Name





Summary


This part covers the most common uses of SelectionList control. The next part of the article would discuss about the the ObjectList control, a highly sophisticated control in the mobile list controls.


Regard

Prateek