Computer Programming

Wednesday, October 23, 2013

If read more about DataTable, then follow How to Use DataTable in C#.

DataTable is the tabular form of data we are storing. Now to create a list, we have to create a list that can contains our desired set of data. List resides in System.Collection.Generic namespace of visual studio. Let suppose, we have a student class with some common properties like name, age, city, and date of birth.

To create a list, just create a list object type of student as in following line of c# code:

public class Student
{
public string Name { get; set; }
public int Age { get; set; }
public string City { get; set; }
public DateTime Dob { get; set; }
}

And the list object will create by the following line:

List<Student> stuList = new List<Student>();

This list can be used further like to insert new record of student, to bind this list with datagridview, to store temporary data from the database and many more. A list have many in-built functions, we have to just analyse them and use them.

This list is empty by default and can contains student type of data only. To insert some data in this list, we have to create a new object of student and then call the add() method of list. The add() method requires a parameter of student type. The syntax of method to add a new student is:

stuList.Add(new Student()
{
Name = "Jacob",
Age = 29,
City = "London",
Dob = new DateTime(1984, 5, 26)
});

This will add a single record of student with above details. We can add as many record as per our requirement.

In the next post we will use some in-built functions which requires Basics of LINQ language.

Tuesday, October 22, 2013

ASP.NET

October 22, 2013

How to check either the CheckBox is Checked or Not

Introduction

You can perform different types of operation on CheckBox Status such as you can check your item either is selected or not. If your CheckBox checked status is true then your CheckBox is selected.

Application of CheckBox Checked status

1. For cookies enable in Facebook Login page.

How to check either the CheckBox is Checked or Not

Lets take a simple example to check that your CheckBox is checked or not

Complete code

<%@ Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

protected void Button1_Click(object sender, EventArgs e)

{

if (CheckBox1.Checked == true)

{

Label1.Text = "CheckBox checked";

}

else

{

Label1.Text = "CheckBox not checked";

}

</script>

<title>How to check either the CheckBox is Checked or Not</title>

</head>

<body>

<div>

<asp:CheckBox ID="CheckBox1" runat="server"

Text="How to check either the CheckBox is Checked or Not" />

<br />

<asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="Check" />

<br />

<asp:Label ID="Label1" runat="server"></asp:Label>

</div>

</form>

</body>

</html>

Output

ASP.NET

October 22, 2013

Programmatically change CheckBox Border Style in ASP.NET

Introduction

If you want to change Border-Style of the CheckBox programmatically then you should use Border-style property at Codebehind. Lets take a simple example for completing this task. Take a WebForm control and place one CheckBox and one Button control onto it.

Algorithm behind the scene is :

Step-1: Assign Border Color to CheckBox control.
Step-2: Set Border Width of the CheckBox Control in Units.
Step-3: Change Border Style.

Complete code

<%@ Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

protected void Button1_Click(object sender, EventArgs e)

{

CheckBox1.BorderColor = System.Drawing.Color.Green;

CheckBox1.BorderWidth = 5;

CheckBox1.BorderStyle = BorderStyle.Outset;

}

protected void Page_Load(object sender, EventArgs e)

{

}

</script>

<title>Change CheckBox border style</title>

#form1 {

height: 78px;

}

</style>

</head>

<body>

<asp:CheckBox ID="CheckBox1" runat="server" Text="Change Border Style" />

<br />

<asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="Change CheckBox Border Style"

Width="198px" />

</form>

</body>

</html>

Output

Programmatically CheckBox Border Style in ASP.NET

ASP.NET

October 22, 2013

ASP.NET: Change DropdownList font name programmatically

Introduction

You can change the font face of the Text which is inside the DropdownList easily. If you want to change the face or family of the text then you must assign name of the face into font name property.

Lets take an simple example to change the font face/family Programmatically

<%@ Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

protected void Button1_Click(object sender, EventArgs e)

{

DropDownList1.Font.Name = "Arial";

}

protected void Button1_Click1(object sender, EventArgs e)

{

DropDownList1.Font.Name = "Algerian";

}

</script>

</head>

<body>

<div>

<asp:DropDownList ID="DropDownList1" runat="server" Height="20px" Width="124px">

<asp:ListItem>Hyperlink</asp:ListItem>

<asp:ListItem>CheckBox</asp:ListItem>

<asp:ListItem>Label</asp:ListItem>

<asp:ListItem>Panel</asp:ListItem>

</asp:DropDownList>

<br />

<asp:Button ID="Button1" runat="server" Text="Change Font size Arial"

onclick="Button1_Click" />

<br />

<asp:Button ID="Button2" runat="server" Text="Change Font size Algerian"

onclick="Button1_Click1" />

<br />

</div>

</form>

</body>

</html>

Output

ASP.NET: Change DropdownList font name programmatically

Monday, October 21, 2013

c# Windows Forms WPF

October 21, 2013

Uses of "Using" Statement in C#

Every object consumes some amount of storage in memory, when created by the programmer. Programmer have to dispose all the objects created and empty the storage allocated. This disposing can be done through Dispose() menthod in in-built IDisposable interface, in Visual Studio.

If programmer don’t release the memory, then it can be done by the CLR, according to its decision to perform garbage collection. Using statement allows the programmer to specify, when to release the resources used. The syntax of using statement:

using (ClassName obj = new ClassName())
{
// Line of code to be executed
}

The ClassName denotes the name of class to which the object is created. Obj is the object, which will be disposed at the last of this scope of “using” statement. The following code will create an object of Student class and when the debugger will reached on last line of code, it will release the memory allocated by the stu object.

using(Student stu = new Student())
{
//Line of code to be executed
}

The other reason of exiting the using statement may be an exception in our line of code. When an exception is generated, it will go to catch method, and dispose method will not be called. So we should use this using statement for better memory management.

ASP.NET

October 21, 2013

ASP.NET : Change DropdownList font Size programmatically

Introduction

FontSize enumeration specifies the font sizes defined by HTML 4.0 . This enumeration available in System.Web.UI.WebControls.FontSize. There are many enumeration value available in FontSize enumeration those are shown below:

ASP.NET : Change DropdownList font Size programmatically

Complete code :

<%@ Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

protected void Button1_Click(object sender, EventArgs e)

{

DropDownList1.Font.Size =FontUnit.XLarge;

}

</script>

</head>

<body>

<div>

<asp:DropDownList ID="DropDownList1" runat="server" Height="20px" Width="124px">

<asp:ListItem>Hyperlink</asp:ListItem>

<asp:ListItem>CheckBox</asp:ListItem>

<asp:ListItem>Label</asp:ListItem>

<asp:ListItem>Panel</asp:ListItem>

</asp:DropDownList>

<br />

<asp:Button ID="Button1" runat="server" Text="Change Font size Dynamically"

onclick="Button1_Click" />

<br />

</div>

</form>

</body>

</html>

Output

ASP.NET

October 21, 2013

Example of FindByText method in ASP.NET

Introduction

Searches the collection for a ListItem with a Text property that equals the specified text(According to msdn library).
Lets take an simple example to remove item from DropdownList using FindByText method. Basically this method works on collection.
Algorithm behind the scene is
Step-1 : Bind DropdownList with some values
Step-2 : Drop TextBox and Button control to the design page.
Step-3: First check the capacity of the DropdownList is more than 0 . if capacity is more than 0 then remove the item from the list using FindByText( ) method.
Step-4: End Program.