ASP .net material Part-5

-

ASP.NET - The SortedList Object

The SortedList object combines the features of both the ArrayList object and the Hashtable object.

The SortedList Object

The SortedList object contains items in key/value pairs. A SortedList object automatically sort the items in alphabetic or numeric order.
Items are added to the SortedList with the Add() method. A SortedList can be sized to its final size with the TrimToSize() method.
The following code creates a SortedList named mycountries and four elements are added:
<script runat="server">
sub Page_Load
if Not Page.IsPostBack then
  dim mycountries=New SortedList
  mycountries.Add("N","Norway")
  mycountries.Add("S","Sweden")
  mycountries.Add("F","France")
  mycountries.Add("I","Italy")
end if
end sub
</script>

Data Binding

A SortedList object may automatically generate the text and values to the following controls:
  • asp:RadioButtonList
  • asp:CheckBoxList
  • asp:DropDownList
  • asp:Listbox
To bind data to a RadioButtonList control, first create a RadioButtonList control (without any asp:ListItem elements) in an .aspx page:
<html>
<body>

<form runat="server">
<asp:RadioButtonList id="rb" runat="server" AutoPostBack="True" />
</form>

</body>
</html>
Then add the script that builds the list:
<script runat="server">
sub Page_Load
if Not Page.IsPostBack then
  dim mycountries=New SortedList
  mycountries.Add("N","Norway")
  mycountries.Add("S","Sweden")
  mycountries.Add("F","France")
  mycountries.Add("I","Italy")
  rb.DataSource=mycountries
  rb.DataValueField="Key"
  rb.DataTextField="Value"
  rb.DataBind()
end if
end sub
</script>

<html>
<body>

<form runat="server">
<asp:RadioButtonList id="rb" runat="server" AutoPostBack="True" />
</form>

</body>
</html>
Then we add a sub routine to be executed when the user clicks on an item in the RadioButtonList control. When a radio button is clicked, a text will appear in a label:

Example

<script runat="server">
sub Page_Load
if Not Page.IsPostBack then
  dim mycountries=New SortedList
  mycountries.Add("N","Norway")
  mycountries.Add("S","Sweden")
  mycountries.Add("F","France")
  mycountries.Add("I","Italy")
  rb.DataSource=mycountries
  rb.DataValueField="Key"
  rb.DataTextField="Value"
  rb.DataBind()
end if
end sub

sub displayMessage(s as Object,e As EventArgs)
lbl1.text="Your favorite country is: " & rb.SelectedItem.Text
end sub
</script>

<html>
<body>

<form runat="server">
<asp:RadioButtonList id="rb" runat="server"
AutoPostBack="True" onSelectedIndexChanged="displayMessage" />
<p><asp:label id="lbl1" runat="server" /></p>
</form>

</body>
</html>

ASP .NET - XML Files

We can bind an XML file to a list control.

An XML File

Here is an XML file named "countries.xml":
<?xml version="1.0" encoding="ISO-8859-1"?>

<countries>

<country>
  <text>Norway</text>
  <value>N</value>
</country>

<country>
  <text>Sweden</text>
  <value>S</value>
</country>

<country>
  <text>France</text>
  <value>F</value>
</country>

<country>
  <text>Italy</text>
  <value>I</value>
</country>

</countries>
Take a look at the XML file: countries.xml

Bind a DataSet to a List Control

First, import the "System.Data" namespace. We need this namespace to work with DataSet objects. Include the following directive at the top of an .aspx page:
<%@ Import Namespace="System.Data" %>
Next, create a DataSet for the XML file and load the XML file into the DataSet when the page is first loaded:
<script runat="server">
sub Page_Load
if Not Page.IsPostBack then
  dim mycountries=New DataSet
  mycountries.ReadXml(MapPath("countries.xml"))
end if
end sub
To bind the DataSet to a RadioButtonList control, first create a RadioButtonList control (without any asp:ListItem elements) in an .aspx page:
<html>
<body>

<form runat="server">
<asp:RadioButtonList id="rb" runat="server" AutoPostBack="True" />
</form>

</body>
</html>
Then add the script that builds the XML DataSet:
<%@ Import Namespace="System.Data" %>

<script runat="server">
sub Page_Load
if Not Page.IsPostBack then
  dim mycountries=New DataSet
  mycountries.ReadXml(MapPath("countries.xml"))
  rb.DataSource=mycountries
  rb.DataValueField="value"
  rb.DataTextField="text"
  rb.DataBind()
end if
end sub
</script>

<html>
<body>

<form runat="server">
<asp:RadioButtonList id="rb" runat="server"
AutoPostBack="True" onSelectedIndexChanged="displayMessage" />
</form>

</body>
</html>
Then we add a sub routine to be executed when the user clicks on an item in the RadioButtonList control. When a radio button is clicked, a text will appear in a label:

Example

<%@ Import Namespace="System.Data" %>

<script runat="server">
sub Page_Load
if Not Page.IsPostBack then
  dim mycountries=New DataSet
  mycountries.ReadXml(MapPath("countries.xml"))
  rb.DataSource=mycountries
  rb.DataValueField="value"
  rb.DataTextField="text"
  rb.DataBind()
end if
end sub

sub displayMessage(s as Object,e As EventArgs)
lbl1.text="Your favorite country is: " & rb.SelectedItem.Text
end sub
</script>

<html>
<body>

<form runat="server">
<asp:RadioButtonList id="rb" runat="server"
AutoPostBack="True" onSelectedIndexChanged="displayMessage" />
<p><asp:label id="lbl1" runat="server" /></p>
</form>

</body>
</html>

ASP.NET - The Repeater Control

The Repeater control is used to display a repeated list of items that are bound to the control.

Bind a DataSet to a Repeater Control

The Repeater control is used to display a repeated list of items that are bound to the control. The Repeater control may be bound to a database table, an XML file, or another list of items. Here we will show how to bind an XML file to a Repeater control.
We will use the following XML file in our examples ("cdcatalog.xml"):
<?xml version="1.0" encoding="ISO-8859-1"?>

<catalog>
<cd>
  <title>Empire Burlesque</title>
  <artist>Bob Dylan</artist>
  <country>USA</country>
  <company>Columbia</company>
  <price>10.90</price>
  <year>1985</year>
</cd>
<cd>
  <title>Hide your heart</title>
  <artist>Bonnie Tyler</artist>
  <country>UK</country>
  <company>CBS Records</company>
  <price>9.90</price>
  <year>1988</year>
</cd>
<cd>
  <title>Greatest Hits</title>
  <artist>Dolly Parton</artist>
  <country>USA</country>
  <company>RCA</company>
  <price>9.90</price>
  <year>1982</year>
</cd>
<cd>
  <title>Still got the blues</title>
  <artist>Gary Moore</artist>
  <country>UK</country>
  <company>Virgin records</company>
  <price>10.20</price>
  <year>1990</year>
</cd>
<cd>
  <title>Eros</title>
  <artist>Eros Ramazzotti</artist>
  <country>EU</country>
  <company>BMG</company>
  <price>9.90</price>
  <year>1997</year>
</cd>
</catalog>
Take a look at the XML file: cdcatalog.xml
First, import the "System.Data" namespace. We need this namespace to work with DataSet objects. Include the following directive at the top of an .aspx page:
<%@ Import Namespace="System.Data" %>
Next, create a DataSet for the XML file and load the XML file into the DataSet when the page is first loaded:
<script runat="server">
sub Page_Load
if Not Page.IsPostBack then
  dim mycdcatalog=New DataSet
  mycdcatalog.ReadXml(MapPath("cdcatalog.xml"))
end if
end sub
Then we create a Repeater control in an .aspx page. The contents of the <HeaderTemplate> element are rendered first and only once within the output, then the contents of the <ItemTemplate> element are repeated for each "record" in the DataSet, and last, the contents of the <FooterTemplate> element are rendered once within the output:
<html>
<body>

<form runat="server">
<asp:Repeater id="cdcatalog" runat="server">

<HeaderTemplate>
...
</HeaderTemplate>

<ItemTemplate>
...
</ItemTemplate>

<FooterTemplate>
...
</FooterTemplate>

</asp:Repeater>
</form>

</body>
</html>
Then we add the script that creates the DataSet and binds the mycdcatalog DataSet to the Repeater control. We also fill the Repeater control with HTML tags and bind the data items to the cells in the<ItemTemplate> section with the <%#Container.DataItem("fieldname")%> method:

Example

<%@ Import Namespace="System.Data" %>

<script runat="server">
sub Page_Load
if Not Page.IsPostBack then
  dim mycdcatalog=New DataSet
  mycdcatalog.ReadXml(MapPath("cdcatalog.xml"))
  cdcatalog.DataSource=mycdcatalog
  cdcatalog.DataBind()
end if
end sub
</script>

<html>
<body>

<form runat="server">
<asp:Repeater id="cdcatalog" runat="server">

<HeaderTemplate>
<table border="1" width="100%">
<tr>
<th>Title</th>
<th>Artist</th>
<th>Country</th>
<th>Company</th>
<th>Price</th>
<th>Year</th>
</tr>
</HeaderTemplate>

<ItemTemplate>
<tr>
<td><%#Container.DataItem("title")%></td>
<td><%#Container.DataItem("artist")%></td>
<td><%#Container.DataItem("country")%></td>
<td><%#Container.DataItem("company")%></td>
<td><%#Container.DataItem("price")%></td>
<td><%#Container.DataItem("year")%></td>
</tr>
</ItemTemplate>

<FooterTemplate>
</table>
</FooterTemplate>

</asp:Repeater>
</form>

</body>
</html>

Show example »

Using the <AlternatingItemTemplate>

You can add an <AlternatingItemTemplate> element after the <ItemTemplate> element to describe the appearance of alternating rows of output. In the following example each other row in the table will be displayed in a light grey color:

Example

<%@ Import Namespace="System.Data" %>

<script runat="server">
sub Page_Load
if Not Page.IsPostBack then
  dim mycdcatalog=New DataSet
  mycdcatalog.ReadXml(MapPath("cdcatalog.xml"))
  cdcatalog.DataSource=mycdcatalog
  cdcatalog.DataBind()
end if
end sub
</script>

<html>
<body>

<form runat="server">
<asp:Repeater id="cdcatalog" runat="server">

<HeaderTemplate>
<table border="1" width="100%">
<tr>
<th>Title</th>
<th>Artist</th>
<th>Country</th>
<th>Company</th>
<th>Price</th>
<th>Year</th>
</tr>
</HeaderTemplate>

<ItemTemplate>
<tr>
<td><%#Container.DataItem("title")%></td>
<td><%#Container.DataItem("artist")%></td>
<td><%#Container.DataItem("country")%></td>
<td><%#Container.DataItem("company")%></td>
<td><%#Container.DataItem("price")%></td>
<td><%#Container.DataItem("year")%></td>
</tr>
</ItemTemplate>

<AlternatingItemTemplate>
<tr bgcolor="#e8e8e8">
<td><%#Container.DataItem("title")%></td>
<td><%#Container.DataItem("artist")%></td>
<td><%#Container.DataItem("country")%></td>
<td><%#Container.DataItem("company")%></td>
<td><%#Container.DataItem("price")%></td>
<td><%#Container.DataItem("year")%></td>
</tr>
</AlternatingItemTemplate>

<FooterTemplate>
</table>
</FooterTemplate>

</asp:Repeater>
</form>

</body>
</html>

Show example »

Using the <SeparatorTemplate>

The <SeparatorTemplate> element can be used to describe a separator between each record. The following example inserts a horizontal line between each table row:

Example

<%@ Import Namespace="System.Data" %>

<script runat="server">
sub Page_Load
if Not Page.IsPostBack then
  dim mycdcatalog=New DataSet
  mycdcatalog.ReadXml(MapPath("cdcatalog.xml"))
  cdcatalog.DataSource=mycdcatalog
  cdcatalog.DataBind()
end if
end sub
</script>

<html>
<body>

<form runat="server">
<asp:Repeater id="cdcatalog" runat="server">

<HeaderTemplate>
<table border="0" width="100%">
<tr>
<th>Title</th>
<th>Artist</th>
<th>Country</th>
<th>Company</th>
<th>Price</th>
<th>Year</th>
</tr>
</HeaderTemplate>

<ItemTemplate>
<tr>
<td><%#Container.DataItem("title")%></td>
<td><%#Container.DataItem("artist")%></td>
<td><%#Container.DataItem("country")%></td>
<td><%#Container.DataItem("company")%></td>
<td><%#Container.DataItem("price")%></td>
<td><%#Container.DataItem("year")%></td>
</tr>
</ItemTemplate>

<SeparatorTemplate>
<tr>
<td colspan="6"><hr /></td>
</tr>
</SeparatorTemplate>

<FooterTemplate>
</table>
</FooterTemplate>

</asp:Repeater>
</form>

</body>
</html> 

Comments

Post a Comment

Popular posts from this blog

what is Event Cache table in sharepoint

-
Every Content database in SharePoint Contains an EventCache table that is the change log for objects contained in the database. Each row in this table is depicting a change in an object where columns usually contain information such as the date and time of a change, the type of object that was changed, the nature of the change, and a unique identifier for the object. EventCache table is important because it stores the list of site events for which users might have requested alerts.
Read more

CAML Query syntax and options in SharePoint

-
As Small syntax error or order of tag in spquery can result any web part (or any thing in which spquery is used) doesn’t work, I’m explaining SPQuery with example, hope which may help you. CAML (Collaborative Application Markup Language) SPQuery  is the SharePoint object which is used to perform a query operation against SharePoint data. SPList.getItems(SPQuery)  is the step, will return SPListItemCollection  which satisfies the query.SPQuery has one data member ‘ Query’ , which need to set before passing SPQuery object to  SPList . Some Properties Properties Description RowLimit Gets or sets a limit for the number of items returned in the query per page. <RowLimit>10</RowLimit> --- Can be used as: query.rowLimit = 10; ViewFields Gets or sets the fields that are displayed in the query. <ViewFields>         <FieldRef Name='Title'/>         <FieldRef Name='Name'/> </ViewFields> --- Can be used as: SP
Read more

Change anchor link url in sharepoint calender

-
here am unsing sharepoint calender to display events. The calender list is inhereted from event content type. for every event there are several columns like event name, event link(URL), Event Date...etc. for some events there may be some url in link column some may be empty. So in calender if i click the event, suppose if that event has the LINK with url then i have to redirect to the new url, if the link url is empty then i have to redirect to the event url. here when am clilcking on anchor tag in calender am calling a rest api function to get the link value of that event. am checking the link value , if value in null then am redirecting to event details and the value is not null then am redirecting to the link which am get from rest api call. here am using two mail functions which are 1)e.stopPropagation(); means it will stop the redirecting value which is assigned initially. 2)e.preventDefault(); means it will stop the default value of the anchor tag href value.
Read more