Often times in code you want to assign one variable to another, but only if the variable is not null. If it is null, you want to populate the target variable with another ( perhaps default ) value. The code normally may look like this using the C# Conditional Operator:

string fileName = tempFileName != null ? tempFileName : “Untitled”;

If tempFileName is not null, fileName = tempFileName, else fileName = “Untitled“.

This can now be abbreviated as follows using the Null-Coalescing Operator:

string fileName = tempFileName ?? “Untitled”;

The logic is the same. If tempFileName is not null, fileName = tempFileName, else fileName = “Untitled“.

The Null-Coalescing Operator comes up a lot with nullable types, particular when converting from a nullable type to its value type:

int? count = null;

int amount = count ?? default(int);

Since count is null, amount will now be the default value of an integer type ( zero ).

These Conditional and Null-Coalescing Operators aren’t the most self-describing operators , but I do love programming in C#!

Reference : http://source.witssquare.com

This simple program will guide how to do client side validation of Form in JavaScript.

In this just make a form as follows:

1. Name : <asp:TextBox ID=”txtName” />
2. Email : <asp:TextBox ID=”txtEmail” />
3. Web URL : <asp:TextBox ID=”txtWebUrl” />
4. Zip : <asp:TextBox ID=”txtZip” />
5. <asp:Button ID=”btnSubmit” OnClientClick=” return validate()” runat=”server” Text=”Submit” />

Now on the source code of this form in script tag write the following code:

<script language=”javascript” type=”text/javascript”>
function validate()
{
if (document.getElementById(“<%=txtName.ClientID%>”).value==“”)
{
alert(“Name Feild can not be blank”);
document.getElementById(“<%=txtName.ClientID%>”).focus();
return false;
}
if(document.getElementById(“<%=txtEmail.ClientID %>”).value==“”)
{
alert(“Email id can not be blank”);
document.getElementById(“<%=txtEmail.ClientID %>”).focus();
return false;
}
var emailPat = /^(\”.*\”|[A-Za-z]\w*)@(\[\d{1,3}(\.\d{1,3}){3}]|[A-Za-z]\w*(\.[A-Za-z]\w*)+)$/;
var emailid=document.getElementById(“<%=txtEmail.ClientID %>”).value;
var matchArray = emailid.match(emailPat);
if (matchArray == null)
{
alert(“Your email address seems incorrect. Please try again.”);
document.getElementById(“<%=txtEmail.ClientID %>”).focus();
return false;
}
if(document.getElementById(“<%=txtWebURL.ClientID %>”).value==“”)
{
alert(“Web URL can not be blank”);
document.getElementById(“<%=txtWebURL.ClientID %>”).value=“http://”
document.getElementById(“<%=txtWebURL.ClientID %>”).focus();
return false;
}
var Url=“^[A-Za-z]+://[A-Za-z0-9-_]+\\.[A-Za-z0-9-_%&\?\/.=]+$”
var tempURL=document.getElementById(“<%=txtWebURL.ClientID%>”).value;
var matchURL=tempURL.match(Url);
if(matchURL==null)
{
alert(“Web URL does not look valid”);
document.getElementById(“<%=txtWebURL.ClientID %>”).focus();
return false;
}
if (document.getElementById(“<%=txtZIP.ClientID%>”).value==“”)
{
alert(“Zip Code is not valid”);
document.getElementById(“<%=txtZIP.ClientID%>”).focus();
return false;
}
var digits=“0123456789″;
var temp;
for (var i=0;i<document.getElementById(“<%=txtZIP.ClientID %>”).value.length;i++)
{
temp=document.getElementById(“<%=txtZIP.ClientID%>”).value.substring(i,i+1);
if (digits.indexOf(temp)==-1)
{
alert(“Please enter correct zip code”);
document.getElementById(“<%=txtZIP.ClientID%>”).focus();
return false;
}
}
return true;
}
</script>

And in code behind file just write the below code.

In C#,

protected void Page_Load(object sender, System.EventArgs e)
{

btnSubmit.Attributes.Add(“onclick”, “return validate()”);

}

In VB,

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
btnSubmit.Attributes.Add(“onclick”, “return validate()”)
End Sub

Reference : http://source.witssquare.com

What Is Windows Communication Foundation?

The global acceptance of Web services, which includes standard protocols for application-to-application communication, has changed software development. For example, the functions that Web services now provide include security, distributed transaction coordination, and reliable communication. The benefits of the changes in Web services should be reflected in the tools and technologies that developers use. Windows Communication Foundation (WCF)…

Read more…

Reference : http://source.witssquare.com/