Zeeshan Ahmed Memon Blog

Thursday, July 16, 2009

The TargetControlID of '_AccordionExtender' is not valid. The value cannot be null or empty.

Once I was working with a Ajax Based Project in .NET. I was using Accordian Pane. My code was like this (Please note this is just a sample code only for readers):

<ajaxToolkit:Accordion runat="server" TransitionDuration="240" FadeTransitions="true" FramesPerSecond="40" SelectedIndex="0" >
<Panes>
<ajaxToolkit:AccordionPane ID="hd1" runat="server">
<Header>
<a href="" onclick="return false" >HEADER 1</a>
</Header>
<Content>
CONTENT OF HEADER 1
</Content>
</ajaxToolkit:AccordionPane>

<ajaxToolkit:AccordionPane ID="hd2" runat="server">
<Header>
<a href="" onclick="return false" >HEADER 2</a>
</Header>
<Content>
CONTENT OF HEADER 2
</Content>
</ajaxToolkit:AccordionPane>
</Panes>
</ajaxToolkit:Accordion>

And I was facing an Error saying

"The TargetControlID of '_AccordionExtender' is not valid. The value cannot be null or empty."

After digging a little bit I found that I have not provided ID to Accordian

<ajaxToolkit:Accordion id="accordian1" runat="server" TransitionDuration="240" FadeTransitions="true" FramesPerSecond="40" SelectedIndex="0" >
<Panes>
<ajaxToolkit:AccordionPane ID="hd1" runat="server">
<Header>
<a href="" onclick="return false" >HEADER 1</a>
</Header>
<Content>
CONTENT OF HEADER 1
</Content>
</ajaxToolkit:AccordionPane>

<ajaxToolkit:AccordionPane ID="hd2" runat="server">
<Header>
<a href="" onclick="return false" >HEADER 2</a>
</Header>
<Content>
CONTENT OF HEADER 2
</Content>
</ajaxToolkit:AccordionPane>
</Panes>
</ajaxToolkit:Accordion>

After providing ID to Accordian its works fine..................

I hope that this post will also help you.

Wednesday, July 15, 2009

HOW TO CONVERT A STRING INTO DATE IN VB.NET OR C#

To Convert a String into Date Format we need date.parseexact() Function.

date.parseExact(date as string, format as string, third attribute)

example

date.parseExact(stDate, "MM-dd-yyyy", nothing)

That's all......... Enjoy.............

WEBCONFIG FILE FOR AJAX IN ASP.NET 2.0 , ASP.NET 3.0 AND ASP.NET 3.5

Dear Friends,

When I have installed VSTS 2008 in my PC, I faced problem in using Ajax Files. I follow all the instructions that was told in vidoes on www.asp.net\learn but no result.

After investing a number of days and hours, I come to the conclusion that I must have to see my old Ajax Projects WebConfig files. When I compare my existing projects webconfig files and old webconfig files I found that they have no Commands to work with Ajax Based Controls.

The reason to publish this webconfig file is to save others time as they might face some time the same problem which I faced and wasted my time.

Below is the entire webconfig file. Simply copy it in your webconfig file or change it as per your need.

<?xml version="1.0"?>

</sectionGroup>

</configSections>

<system.web>

<pages>

</pages>

<!--

Set compilation debug="true" to insert debugging

symbols into the compiled page. Because this

affects performance, set this value to true only

during development.

-->

</compilation>

</httpHandlers>

</httpModules>

</system.web>

<system.web.extensions>

<!--

</converters>

</jsonSerialization>

-->

<!--

-->

<!-- Uncomment these lines to enable the profile service. To allow profile properties to be retrieved

and modified in ASP.NET AJAX applications, you need to add each property name to the readAccessProperties and

writeAccessProperties attributes. -->

<!--

<profileService enabled="true"

readAccessProperties="propertyname1,propertyname2"

writeAccessProperties="propertyname1,propertyname2" />

-->

</webServices>

<!--

-->

</scripting>

</system.web.extensions>

<system.webServer>

</modules>

</handlers>

</system.webServer>

<system.codedom>

Wednesday, July 1, 2009

How to Insert a new Node in XML File in C#

This is 4th post regarding XML. In this, I will teach you how to insert a new node in XML file.

The sample XML file is shown below which is before Inserting new Node.

<?xml version="1.0"?>
<Library>
<Subjects name="Computer Science">
<Publishers name="Wrox">
<Begginers>Beginning C#</Begginers>
</Publishers>
</Subjects>
</Library>

Now write the below code to insert a new node in XML.

XmlDocument xmldoc = new XmlDocument();
xmldoc.Load(filename);
//Create New Element
XmlElement element = xmldoc.CreateElement("Begginers");
element.InnerText = "BEGINNER C# (INDIAN WRITER)";
//Insert Node after Publishers
xmldoc.DocumentElement["Subjects"].ChildNodes[0].InsertAfter(element, xmldoc.DocumentElement["Subjects"].ChildNodes[0].LastChild);
FileStream fsxml = new FileStream(filename, FileMode.Truncate, FileAccess.Write, FileShare.ReadWrite);
xmldoc.Save(fsxml);
Console.WriteLine("XML Updated Successfully");

After executing this code you will get the following output.

<?xml version="1.0"?>
<Library>
<Subjects name="Computer Science">
<Publishers name="Wrox">
<Begginers>Beginning C#</Begginers>
<Begginers>BEGINNER C# (INDIAN WRITER)</Begginers>
</Publishers>
</Subjects>
</Library>

How to Insert an New Element in XML File in C#

This is my third post in which I tell you how to Insert an Element in XML file.

The sample XML file is shown below

<?xml version="1.0"?>
<Library>
<Subjects name="Computer Science">
<Publishers name="Wrox">
<Begginers>Beginning C#</Begginers>
</Publishers>
</Subjects>
</Library>

Now you write the code to insert a new Element.

XmlDocument xmldoc = new XmlDocument();
xmldoc.Load(filename);
//New XML ELEMENT Created
XmlElement xElement = xmldoc.CreateElement("Publishers");

//NEW XML ATTRIBUTE Created
XmlAttribute xAttribute = xmldoc.CreateAttribute("name");
xAttribute.Value = "Indian Book";
xElement.SetAttributeNode(xAttribute);

//Create Inner Element
XmlElement element = xmldoc.CreateElement("Begginers");
element.InnerText = "BEGINNER C# (INDIAN WRITER)";
xElement.AppendChild(element);
xmldoc.DocumentElement.InsertAfter(xElement, xmldoc.DocumentElement.LastChild);

FileStream fsxml = new FileStream(filename, FileMode.Truncate, FileAccess.Write, FileShare.ReadWrite);
xmldoc.Save(fsxml);
Console.WriteLine("XML Updated Successfully");

After executing this code. you will get the following output xml.

<?xml version="1.0"?>
<Library>
<Subjects name="Computer Science">
<Publishers name="Wrox">
<Begginers>Beginning C#</Begginers>
</Publishers>
</Subjects>
<Publishers name="Indian Book">
<Begginers>BEGINNER C# (INDIAN WRITER)</Begginers>
</Publishers>
</Library>

How TO READ XML IN C#

This is my Second post regarding XML. In first post i told you that how to create a xml file in C#. Now we will learn that how can we read a xml file in c#.

To read an XML file in c# you need to add a namespace.

using System.XML;

Now write the below code to read xml file.

XmlTextReader reader = new XmlTextReader(filename);
reader.Read();
while (reader.Read())
{
if(reader.Value.Trim()!="")
Console.WriteLine("Attribute Count={0}, Attribute={1}, Value={2}", reader.AttributeCount, reader.GetAttribute("name"),reader.Value);
}

I used this code to get my result which I want. You can modify the code to get yours one.

Enjoy..........

HOW TO WRITE XML IN C#

Below is the code in C# which you can use to create an XML file.

Note: You must include System.XML namespace. You can do so by writing the below command.

using System.XML;

The sample of XML is shown below:

<?xml version="1.0"?>
<Library>
<Subjects name="Computer Science">
<Publishers name="Wrox">
<Begginers>Beginning C#</Begginers>
</Publishers>
</Subjects>
</Library>

Now write the below code to get the above result.

XmlTextWriter writer = new XmlTextWriter(filename, null);
//SELECT THE FORMATTING STYLE (INDENTED, NONE)
writer.Formatting = Formatting.Indented;
//STARTING TAG
writer.WriteStartDocument();
//STARTING "Root"
writer.WriteStartElement("Library");
//STARTING ELEMENT NAMED "COMPUTER SCIENCE"
writer.WriteStartElement("Subjects");
writer.WriteAttributeString("name", "Computer Science");
//FURTHER ELEMENT NAMED "COMPUTER SCIENCE"
writer.WriteStartElement("Publishers");
writer.WriteAttributeString("name", "Wrox");
writer.WriteStartElement("Begginers");
writer.WriteString("Beginning C#");
writer.WriteEndElement();
writer.WriteEndElement();
writer.WriteEndElement();
writer.WriteEndElement();
writer.WriteEndDocument();
writer.Close();
Console.WriteLine("XML Written Successfully");

Zeeshan Ahmed Memon Blog

Thursday, July 16, 2009

The TargetControlID of '_AccordionExtender' is not valid. The value cannot be null or empty.

Wednesday, July 15, 2009

HOW TO CONVERT A STRING INTO DATE IN VB.NET OR C#

WEBCONFIG FILE FOR AJAX IN ASP.NET 2.0 , ASP.NET 3.0 AND ASP.NET 3.5

Wednesday, July 1, 2009

How to Insert a new Node in XML File in C#

How to Insert an New Element in XML File in C#

How TO READ XML IN C#

HOW TO WRITE XML IN C#

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