SQL Server - Remove or Truncate or Subtract hours, minutes, seconds and milliseconds from sql datetime

While working on SQL Datetime sometimes we may get a requirement to subtract hours, minutes, seconds and milliseconds from sql datetime. We can do it by using the following code snippet.

Remove/Truncate/Subtract hours, minutes, seconds and milliseconds from sql datetime

SELECT GETDATE()

-- 2014-08-25 13:19:13.157

SELECT CONVERT(DATETIME,CONVERT(char(10), GetDate(), 120))

-- 2014-08-25 00:00:00.000

SELECT

          DATEADD(MILLISECOND,(0-DATEPART(MILLISECOND,GETDATE())),

          DATEADD(SECOND,(0-DATEPART(SECOND,GETDATE())),

          DATEADD(MINUTE,(0-DATEPART(MINUTE,GETDATE())),

          (DATEADD(HOUR,(0-DATEPART(HOUR,GETDATE())),GETDATE())))))

-- 2014-08-25 00:00:00.000

SQL Server 2005/2008 - Working with datetime Data Type (DATENAME, DATEPART, DATEDIFF, DATEADD, ISDATE, CONVERT)

When we are working with any programming language we need to work on the datetime. Every geographic location has different need of the date formats. Developer needs to take care of the datetime formats. The following statements are the most useful and common DateTime functions which are useful in SQL Server 2005/2008. I am giving with some example sql queries with the outputs.

Working With SQL datetime Data Type

SELECT

GETDATE(), -- 2014-07-23 00:48:46.663

CURRENT_TIMESTAMP, -- 2014-07-23 00:48:46.663

GETUTCDATE(), -- 2014-07-22 19:18:46.663

DAY(GETDATE()) , -- 23

MONTH(GETDATE()) , -- 7

YEAR(GETDATE())  -- 2014

--DATENAME

SELECT

DATENAME(year, getdate()) -- 2014

,DATENAME(month, getdate()) -- July

,DATENAME(day, getdate()) -- 23

,DATENAME(dayofyear, getdate()) -- 204

,DATENAME(weekday, getdate()) -- Wednesday

,DATENAME(hour, getdate()) -- 0

,DATENAME(minute, getdate()) -- 53

,DATENAME(second, getdate()) -- 57

,DATENAME(millisecond, getdate()) -- 140

--DATEPART

SELECT

DATEPART(year, getdate()) -- 2014

,DATEPART(month, getdate()) -- 7

,DATEPART(day, getdate()) -- 23

,DATEPART(dayofyear, getdate()) -- 204

,DATEPART(weekday, getdate()) -- 4

,DATEPART(hour, getdate()) -- 0

,DATEPART(minute, getdate()) -- 53

,DATEPART(second, getdate()) -- 57

,DATEPART(millisecond, getdate()) -- 140

-- DATEDIFF

DECLARE @startdate  DATETIME

SET @startdate = '2014-08-15 10:10:10.100'

DECLARE @enddate DATETIME

SET @enddate = '2014-08-20 20:20:20.200';

SELECT

DATEDIFF(year, @startdate, @enddate) , -- 0

DATEDIFF(month, @startdate, @enddate) , -- 0

DATEDIFF(hour, @startdate, @enddate) , -- 130

DATEDIFF(minute, @startdate, @enddate) , -- 7810

DATEDIFF(second, @startdate, @enddate) , --468610

DATEDIFF(millisecond, @startdate, @enddate)  --468610100

-- DATEADD

DECLARE @datetime datetime

SET @datetime = '2014-01-01 01:01:01.110'

SELECT DATEADD(quarter,4,@datetime) -- 2015-01-01 01:01:01.110

SELECT DATEADD(month,13,@datetime) -- 2015-02-01 01:01:01.110    

SELECT DATEADD(dayofyear,365,@datetime) -- 2015-01-01 01:01:01.110

SELECT DATEADD(day,365,@datetime) -- 2015-01-01 01:01:01.110     

SELECT DATEADD(week,5,@datetime)-- 2014-02-05 01:01:01.110

SELECT DATEADD(weekday,31,@datetime) -- 2014-02-01 01:01:01.110

SELECT DATEADD(hour,23,@datetime) -- 2014-01-02 00:01:01.110

SELECT DATEADD(minute,59,@datetime) -- 2014-01-01 02:00:01.110

SELECT DATEADD(second,59,@datetime) -- 2014-01-01 01:02:00.110

SELECT DATEADD(millisecond,1,@datetime) -- 2014-01-01 01:01:01.110

--ISDATE

SELECT ISDATE('2014-12-30 01:01:01.001')  -- 1

SELECT ISDATE('12-30-2014 01:01:01.001')  -- 1

SELECT ISDATE('30-12-2014 01:01:01.001')  -- 0

SELECT ISDATE('2014/12/30 01:01:01.001')  -- 1

SELECT ISDATE('12/30/2014 01:01:01.001')  -- 1

SELECT ISDATE('30/12/2014 01:01:01.001')  -- 0

SELECT ISDATE(NULL)  -- 0

SELECT ISDATE('')  -- 0

SELECT ISDATE('SRINU')  -- 0

-- CONVERT

DECLARE @INPUTDATE DATETIME

SET @INPUTDATE='2014-12-30 12:59:59'

SELECT CONVERT(VARCHAR(10), @INPUTDATE, 105) , '[dd-mm-yyyy]'

-- 30-12-2014  [dd-mm-yyyy]

SELECT CONVERT(VARCHAR(10), @INPUTDATE, 110), '[mm-dd-yyyy]'

-- 12-30-2014      [mm-dd-yyyy]

SELECT CONVERT(VARCHAR(10), @INPUTDATE , 120), '[yyyy-mm-dd]'

-- 2014-12-30      [YYYY-MM-DD]

SELECT CONVERT(VARCHAR(10), @INPUTDATE, 103) ,' [dd/mm/yyyy]'

-- 30/12/2014    [dd/mm/yyyy]

SELECT CONVERT(VARCHAR(10), @INPUTDATE, 101) ,'[mm/dd/yyyy]'

-- 12/30/2014    [mm/dd/yyyy]

SELECT CONVERT(VARCHAR(10), @INPUTDATE, 111) ,'[yyyy/mm/dd]'

-- 2014/12/30    [yyyy/mm/dd]

SELECT CONVERT(VARCHAR(12),@INPUTDATE, 102),'[yyyy.mm.dd]'

-- 2014.12.30     [yyyy.mm.dd]

SELECT CONVERT(VARCHAR(12),@INPUTDATE, 104),'[dd.mm.yyyy]'

-- 30.12.2014     [dd.mm.yyyy]

SELECT CONVERT(VARCHAR(12), @INPUTDATE, 107) ,'[mmm dd, yyyy]'

-- Dec 30, 2014  [mmm dd, yyyy]

SELECT CONVERT(VARCHAR(8), @INPUTDATE, 108) , '[HH:mm:ss]'

-- 12:59:59         [HH:mm:ss]

SELECT CONVERT(VARCHAR(12), @INPUTDATE, 114) 'HH:mm:ss:fff'

-- 12:59:59:000 [HH:mm:ss:fff]

C#.NET - How to assign null value to DateTime / Working with nullable DateTime / Assigning null value to DateTime / Setting DateTime to null

Value types are non nullable. Reference types are nullable.

DateTime is a value type. If you try to assign null value to DateTime it will throw compile time error "Cannot convert null to System.DateTime because it is a non-nullable value type."

DateTime has the default value that is equal to the DateTime.MinValue. You can assign this to DateTime.

In C# 2.0, Microsoft introduced "Nullable Types" using the nullable operator (?). It will allow you to assign the null values to the value types. So we can assgin a null value to the DateTime by making it as Nullable Type.

CSS - Style Sheet Media Types

By using the media type rules ( @media ) we can present our web page with a different look in different devices such as screen, print, mobile phone, tablet, etc.

There are different media types defined in the CSS-2 specifications.

Media Type	Description
all	Used for all media type devices
aural	Used for speech and sound synthesizers
braille	Used for braille tactile feedback devices
embossed	Used for paged braille printers
print	Used for printers
projection	Used for projected presentations, like slides
screen	Used for computer screens
tty	Used for media using a fixed-pitch character grid, like teletypes and terminals
tv	Used for television-type devices

We can define media types in different ways

1. External Style Sheet associated with single media type.

<link rel="stylesheet" type="text/css" href="print.css" media="print" />

2. External Style Sheet associated with multiple media types.

<link rel="stylesheet" type="text/css" href="print.css" media="print,handheld" />

3. Imported Stylesheets

<style type="text/css" media="print, handheld">
@import "print.css";
</style>

4. Internal Style Sheet associated with single media type.

<style type="text/css" media="print">
h1
{
font-size:16px;
color:Green;
}
</style>

5. Internal Style Sheet associated with multiple media types.

<style type="text/css" media="print,handheld">
h1
{
font-size:16px;
color:Green;
}
</style>

6. Inline style sheets, with the @media rule

<style type="text/css">
@media print
{
h1
{
font-size:16px;
color:Black;
}
}
@media screen
{
h1
{
font-size:18px;
color:Green;
}
}
@media screen, print
{
h1
{
font-size:1.5;
color:Blue;
}
}
</style>

C#.NET - How to delete XML Node from XML file step by step

In this article you will get to know how to delete an Xml Node from the Xml Document.

We have an XmlDocument class in System.Xml namespace. With the help of XmlDocument class data members and member functions we can delete node from the Xml Document.

To delete an Xml node from the Xml Document go through the following step by step procedure.

1. First create an Xml File with some sample employees as follows.

Xml File

<?xml version="1.0" encoding="utf-8"?>
<Employees>
  
  <Employee>
    <ID>SE01</ID>
    <Name>Srinubabu</Name>
    <Address>Hyderabad</Address>   
  </Employee>

  <Employee>
    <ID>SE02</ID>
    <Name>Gajendra</Name>
    <Address>Pune</Address>
  </Employee>

  <Employee>
    <ID>SE03</ID>
    <Name>Prafulla</Name>
    <Address>Gurgon</Address>
  </Employee>

  <Employee>
    <ID>SE02</ID>
    <Name>Satheesh</Name>
    <Address>Chennai</Address>
  </Employee>
  
</Employees>

2. Create a new website in Visual Studio.

3. Add an aspx page "Delete-node-from-xml.aspx" to the website and write the following code.

Note: Please go through the code and comments in the following code you will easily understand the process of deleting the node from Xml Document.

Delete-node-from-xml.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Delete-node-from-xml.aspx.cs"
    Inherits="Delete_node_from_xml" %>

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<body>
    <form id="form1" runat="server">
    Employee ID:
    <asp:TextBox ID="txtEmployeeID" runat="server" />
    <asp:Button ID="btnDeleteEmployee" Text="Delete Employee" runat="server" OnClick="btnDeleteEmployee_Click" /><br />
    <br />
    <asp:Label ID="lblStatus" ForeColor="Red" Font-Size="13" Text="" runat="server" />
    </form>
</body>
</html>

Delete-node-from-xml.aspx.cs

using System;
using System.Xml;

public partial class Delete_node_from_xml : System.Web.UI.Page
{
   
    protected void btnDeleteEmployee_Click(object sender, EventArgs e)
    {
        var filePath = @"C:\Users\manduvalkuritis\Desktop\Srinubabu\XMLManipulations\Employees.xml";
        DeleteEmployeeByEmployeeID(filePath, txtEmployeeID.Text.Trim());
    }

    private void DeleteEmployeeByEmployeeID(string xmlFilePath, string employeeID)
    {
        // Initialize a new instance of the XmlDocument.
        var xdoc = new XmlDocument();
        xdoc.Load(xmlFilePath);

        // Get the root XmlElement of the document.
        XmlNode rootNode = xdoc.DocumentElement;

        // Select a list of Xml nodes matching with employee ID
        XmlNodeList nodes = rootNode.SelectNodes("Employee");

        bool isEmployeeFound = false;

        // Go throug each and every element 
        foreach (XmlNode item in nodes)
        {
            // Find the Xml node with the given employee ID
            if (item.SelectSingleNode("ID").InnerText == employeeID)
            {
                isEmployeeFound = true;

                // Delete the employee node from the xml document.;
                rootNode.RemoveChild(item);
            }
        }

        if (isEmployeeFound)
        {
            lblStatus.Text = "Emloyee Deleted Successfully.";
        }
        else
        {
            lblStatus.Text = "Emloyee doesn't found please enter correct employee id.";
        }

        // Finally save the xml file.
        xdoc.Save(xmlFilePath);
    }
}

4. Now run the page in browser the output of the page looks as follows.



5. Enter an invalid employee id which was not available in Xml Document and then click on delete button. It will show the error message as follows.



6. Now enter a valid employee id and click on delete button. Now an employee node will be delete from the xml document.



7. Now open the Xml file and observe an employee node with the id "". The employee node with the employee id "" deleted from the Xml file.

Xml File

<?xml version="1.0" encoding="utf-8"?>
<Employees>
  
  <Employee>
    <ID>SE02</ID>
    <Name>Gajendra</Name>
    <Address>Pune</Address>
  </Employee>
  
  <Employee>
    <ID>SE03</ID>
    <Name>Prafulla</Name>
    <Address>Gurgon</Address>
  </Employee>
  
  <Employee>
    <ID>SE02</ID>
    <Name>Satheesh</Name>
    <Address>Chennai</Address>
  </Employee>
  
</Employees>

So, In this way we can delete a node from the Xml Document.

Thank you....

C#.NET - Programming code to generate pyramid or triangle with '*' character

Today you will learn how to generate a pyramid or triangle with characters. Generally you may get this type of requirement in interview to test your coding skills.

Here I created one class in Console Application. Save this as a *.cs file and run it within your Console Application.

C# code to generate pyramid with characters

using System;
using System.Text;

class PrintPyramid
{
    static void Main()
    {
        // Ask for the number to generate pyramid.
        Console.Write("Please enter number to generate triangle: ");
        // Get the input value.
        var noOfRows = Convert.ToInt64(Console.ReadLine());

        // Generate pyramid with the given value.
        GenerateTriangle(noOfRows, '*');

        // Wait for the response from command line.
        Console.ReadLine();
    }

    // Method to generate pyramid
    private static void GenerateTriangle(long noOfRows, char charForTriangle)
    {
        // Create an instance of type StringBuilder to store spaces.
        var sbSpaces = new StringBuilder();

        // Add Spaces to the StringBuilder.
        for (int spaces = 1; spaces < noOfRows; spaces++)
        {
            sbSpaces.Append(" ");
        }

        // Take initial row value as 1.
        var noPrint = 1;
        for (long number = 1; number <= noOfRows; number++)
        {
            // Print spaces first.
            Console.Write(sbSpaces);

            // Print 'X' in a single line to generate proper pyramid.
            for (long i = 1; i <= noPrint; i++)
            {
                Console.Write(charForTriangle);
            }

            // After printing one line come to second line.
            Console.WriteLine();

            // Increment noPrint value to add more 'X' to line.
            noPrint += 2;

            // Each time remove one space from StringBuilder to generate pyramid.
            if (sbSpaces.Length > 0)
                sbSpaces.Remove(0, 1);
        }
    }
}

Output:

C#.NET Program to generate Prime Numbers

Prime number:
A number which is greater than 1 and divisible by 1 or itself is called prime number.
2 is an even prime number because it is evenly divisible by itself and divisible by 1.
All even numbers are not prime numbers. If the last digit of the number contains 0 2 4 6 8 then the number divisible by 2 thus the number is not a prime number.

Ex: First few prime numbers are 2, 3, 5, 7, 11, 13 ..........

Here I am posting a code snippet how to generate Prime Numbers.

C# Prime Numbers Generator

using System;
using System.Collections.Generic;

namespace ConsoleApplication1
{
    class PrimeNumbers
    {
        static void Main()
        {
            Console.Write("Please enter a number to generate prime numbers: ");

            var ipVal = Convert.ToInt64(Console.ReadLine());

            var primeNumbers = GetPrimeNumbersUpTo(ipVal);

            PrintPrimeNumbers(primeNumbers, ipVal);

            Console.ReadLine();
        }

        private static void PrintPrimeNumbers(List<long> primeNumbers, long range)
        {
            Console.WriteLine();
            Console.WriteLine("Prime numbers between 2 to " + range);
            foreach (long item in primeNumbers)
            {
                Console.WriteLine(item);
            }
        }

        private static List<long> GetPrimeNumbersUpTo(long ipVal)
        {
            var primeList = new List<long>();
            for (long value = 2; value <= ipVal; value++)
            {
                if (IsPrimeNumber(value))
                {
                    primeList.Add(value);
                }
            }
            return primeList;
        }

        private static bool IsPrimeNumber(long inputValue)
        {
            if (inputValue == 0 || inputValue == 1)
            {
                return false;
            }

            if (inputValue == 2)
            {
                return true;
            }

            var roundedVal = (long)Math.Round(Math.Sqrt(inputValue));

            for (long i = 2; i <= roundedVal; i++)
            {
                if (inputValue % i == 0)
                {
                    return false;
                }
            }
            return true;
        }
    }
}

Output:

C#.NET program to check whether a given number is prime number or not.

Prime number:
A number which is greater than 1 and divisible by 1 or itself is called prime number.
2 is an even prime number because it is evenly divisible by itself and divisible by 1.
All even numbers are not prime numbers. If the last digit of the number contains 0 2 4 6 8 then the number divisible by 2 thus the number is not a prime number.

Ex: First few prime numbers are 2, 3, 5, 7, 11, 13 ..........

Here I am posting a code snippet to find whether a given number is prime number or not.

C# Program For Prime Number

using System;

namespace ConsoleApplication1
{

    class Program
    {
        static void Main()
        {
            Console.Write("Please enter number to check prime or not: ");
            long inputValue = Convert.ToInt32(Console.ReadLine());

            if (IsPrimeNumber(inputValue))
            {
                Console.WriteLine(inputValue + " is prime number");
            }
            else
            {
                Console.WriteLine(inputValue + " is not prime number");
            }

            Console.ReadLine();
        }

        private static bool IsPrimeNumber(long inputValue)
        {
            if (inputValue == 0 ||inputValue == 1)
            {
                return false;
            }

            if (inputValue == 2)
            {
                return true;
            }

            var roundedVal = (long)Math.Round(Math.Sqrt(inputValue));

            for (long i = 2; i <= roundedVal; i++)
            {
                if (inputValue % i == 0)
                {
                    return false;
                }
            }
            return true;
        }

    }
}

Output:

C#.NET, ASP.NET - Generate non repeated random numbers in C#.NET within the range with the help of Random class.

Hi All,
In this article I will show you how to generate a non repeated random number in between specified range step by step with the explination of code in C#.NET with the help of ASP.NET page.

First please have a look at the complete script page and code behind file.

Generate-Random-Number.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Generate-Random-Number.aspx.cs" Inherits="Scripts_MAR_RandomNumber" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
    <style type="text/css">
        table tr td:first-child
        {
            width: 45px;
        }
    </style>
</head>
<body>
    <form id="form1" runat="server">
        Enter Number: 
        <table class="auto-style1">
            <tr>
                <td>From:</td>
                <td>
                    <asp:TextBox ID="txtFrom" MaxLength="4" runat="server"></asp:TextBox></td>
            </tr>
            <tr>
                <td>To:</td>
                <td>
                    <asp:TextBox ID="txtTo" MaxLength="4" runat="server"></asp:TextBox></td>
            </tr>
            <tr>
                <td></td>
                <td>
                    <asp:Button ID="btnGenerate" runat="server" Text="Generate" OnClick="btnGenerate_Click" />
                </td>
            </tr>
            <tr>
                <td colspan="2">
                    <asp:Label ID="lblStatus" runat="server" ForeColor="Red" Text=""></asp:Label>
                </td>
            </tr>
            <tr>
                <td colspan="2">
                    <asp:TextBox ID="txtRandomNumbers" TextMode="MultiLine" runat="server" Height="113px" Width="434px"></asp:TextBox>
                </td>
            </tr>
        </table>
    </form>
</body>
</html>

Generate-Random-Number.aspx.cs

using System;
using System.Collections.Generic;
using System.Text;

public partial class Scripts_MAR_RandomNumber : System.Web.UI.Page
{
    
    protected void btnGenerate_Click(object sender, EventArgs e)
    {
        // Check the From and To fields have a valid numeric numbers.
        if (IsValidForm())
        {
            // Generate Random Numbers.
            var randomNumers = GenerateRandomNumbers(Convert.ToInt32(txtFrom.Text), Convert.ToInt32(txtTo.Text));

            // Write random numbers to TextBox.
            PrintRandomNumbers(randomNumers);
        }
    }

    // Method to write non repeated random numbers to the TextBox.
    private void PrintRandomNumbers(List<int> randomNumers)
    {
        // Create a StringBuilder to hold the random numbers.
        var sbNumbers = new StringBuilder();
        foreach (var number in randomNumers)
        {
            // Add random numbers from List to StringBuilder.
            sbNumbers.Append(number + ", ");
        }

        // Write random numbers from StringBuilder to TextBox
        txtRandomNumbers.Text = sbNumbers.ToString();
    }

    // Method to generate non repeat random numbers.
    private List<int> GenerateRandomNumbers(int minValue, int maxValue)
    {
        // Create an instance of Random class.
        var randGenerator = new Random();

        // Create an instance of List<int> to store random numbers.
        var randValues = new List<int>();

        int randNum = 0;

        for (int value = minValue; value <= maxValue; value++)
        {
            // Generate a new random number between range (Min, Max). 
            randNum = randGenerator.Next(minValue, maxValue + 1);

            // Check if the new generated random number is existed in List.
            while (randValues.Contains(randNum))
            {
                // If the the number exists generate new random number with in the range (Min, Max).
                randNum = randGenerator.Next(minValue, maxValue + 1);
            }

            // Add non repeated random number to the List
            randValues.Add(randNum);
        }

        // Return non repeated random numbers List.
        return randValues;
    }

    // Method to check the values are entered in the From field and To field are numeric are not.
    private bool IsValidForm()
    {
        var validForm = true;
        int value = 0;

        // Check From value is empty or not.
        if (string.IsNullOrWhiteSpace(txtFrom.Text))
        {
            validForm = false;
            lblStatus.Text = "Please enter From value.";
        }
        else
            // Check From value is integer or not.
            if (!int.TryParse(txtFrom.Text, out value))
            {
                validForm = false;
                lblStatus.Text = "Please enter valid numeric value in From field.";
            }
            else
                // Check From value is negative or not.
                if (Convert.ToInt32(txtFrom.Text) < 0)
                {
                    validForm = false;
                    lblStatus.Text = "Please enter positive value in From field.";
                }
        // If the value entered in From field is valid then check for To value.
        if (validForm)
        {
            // Check To value is empty or not.
            if (string.IsNullOrWhiteSpace(txtTo.Text))
            {
                validForm = false;
                lblStatus.Text = "Please enter To value.";
            }
            else
                // Check To value is integer or not
                if (!int.TryParse(txtTo.Text, out value))
                {
                    validForm = false;
                    lblStatus.Text = "Please enter valid numeric value in To field.";
                }
                else
                    // Check To value is negative or not
                    if (Convert.ToInt32(txtTo.Text) < 0)
                    {
                        validForm = false;
                        lblStatus.Text = "Please enter positive value in To field.";
                    }
        }
        // If both From and To fields are integers then check for "From value < To value"
        if (validForm)
        {
            if (Convert.ToInt32(txtFrom.Text) >= Convert.ToInt32(txtTo.Text))
            {
                validForm = false;
                lblStatus.Text = "From value should be less than To value.";
            }
        }
        if (validForm)
        {
            if (Convert.ToInt32(txtTo.Text) < Convert.ToInt32(txtFrom.Text))
            {
                validForm = false;
                lblStatus.Text = "To value should be greater than From value.";
            }
        }

        // Return the form is valid or invalid.
        return validForm;
    }
}

Step By Step Explanation:

1. Create an interface with two TextBoxes and one Button as shown in the Script page.

2. In the Button click event write the following code.

protected void btnGenerate_Click(object sender, EventArgs e)
    {
        // Check the From and To fields have a valid numeric numbers.
        if (IsValidForm())
        {
            // Generate Random Numbers.
            var randomNumers = GenerateRandomNumbers(Convert.ToInt32(txtFrom.Text), Convert.ToInt32(txtTo.Text));

            // Write random numbers to TextBox.
            PrintRandomNumbers(randomNumers);
        }
    }

The above Button click code is using 3 different methods to process different actions.

3. Write a method IsValidForm() to check the form fields are satisfying the following conditions. -  Check From value is empty or not.
-  Check From value is integer or not.
-  Check From value is negative or not.
-  If the value entered in From field is valid then check for To value.
-  Check To value is empty or not.
-  Check To value is negative or not
-  If both From and To fields are integers then check for "From value < To value"
-  Return the form is valid or invalid.

// Method to check the values are entered in the From field and To field are numeric are not.
    private bool IsValidForm()
    {
        var validForm = true;
        int value = 0;

        // Check From value is empty or not.
        if (string.IsNullOrWhiteSpace(txtFrom.Text))
        {
            validForm = false;
            lblStatus.Text = "Please enter From value.";
        }
        else
            // Check From value is integer or not.
            if (!int.TryParse(txtFrom.Text, out value))
            {
                validForm = false;
                lblStatus.Text = "Please enter valid numeric value in From field.";
            }
            else
                // Check From value is negative or not.
                if (Convert.ToInt32(txtFrom.Text) < 0)
                {
                    validForm = false;
                    lblStatus.Text = "Please enter positive value in From field.";
                }
        // If the value entered in From field is valid then check for To value.
        if (validForm)
        {
            // Check To value is empty or not.
            if (string.IsNullOrWhiteSpace(txtTo.Text))
            {
                validForm = false;
                lblStatus.Text = "Please enter To value.";
            }
            else
                // Check To value is integer or not
                if (!int.TryParse(txtTo.Text, out value))
                {
                    validForm = false;
                    lblStatus.Text = "Please enter valid numeric value in To field.";
                }
                else
                    // Check To value is negative or not
                    if (Convert.ToInt32(txtTo.Text) < 0)
                    {
                        validForm = false;
                        lblStatus.Text = "Please enter positive value in To field.";
                    }
        }
        // If both From and To fields are integers then check for "From value < To value"
        if (validForm)
        {
            if (Convert.ToInt32(txtFrom.Text) >= Convert.ToInt32(txtTo.Text))
            {
                validForm = false;
                lblStatus.Text = "From value should be less than To value.";
            }
        }
        if (validForm)
        {
            if (Convert.ToInt32(txtTo.Text) < Convert.ToInt32(txtFrom.Text))
            {
                validForm = false;
                lblStatus.Text = "To value should be greater than From value.";
            }
        }

        // Return the form is valid or invalid.
        return validForm;
    }

4. Write a method GenerateRandomNumbers(int minValue, int maxValue) to generate the non repeated random numbers with the following the steps.
- Create an instance of Random class.
- Create an instance of List<int> to store random numbers.
- Generate a new random number between range (Min, Max). 
- Check if the new generated random number is existed in List.
- If the the number exists generate new random number with in the range (Min, Max).
- Add non repeated random number to the List
- Return non repeated random numbers List.

// Method to generate non repeat random numbers.
    private List<int> GenerateRandomNumbers(int minValue, int maxValue)
    {
        // Create an instance of Random class.
        var randGenerator = new Random();

        // Create an instance of List<int> to store random numbers.
        var randValues = new List<int>();

        int randNum = 0;

        for (int value = minValue; value <= maxValue; value++)
        {
            // Generate a new random number between range (Min, Max). 
            randNum = randGenerator.Next(minValue, maxValue + 1);

            // Check if the new generated random number is existed in List.
            while (randValues.Contains(randNum))
            {
                // If the the number exists generate new random number with in the range (Min, Max).
                randNum = randGenerator.Next(minValue, maxValue + 1);
            }

            // Add non repeated random number to the List
            randValues.Add(randNum);
        }

        // Return non repeated random numbers List.
        return randValues;
    }

5. Write a method  PrintRandomNumbers(List<int> randomNumers) to print the values in TextBox.
- Create a StringBuilder to hold the random numbers.
- Add random numbers from List to StringBuilder.
- Write random numbers from StringBuilder to TextBox

// Method to write non repeated random numbers to the TextBox.
    private void PrintRandomNumbers(List<int> randomNumers)
    {
        // Create a StringBuilder to hold the random numbers.
        var sbNumbers = new StringBuilder();
        foreach (var number in randomNumers)
        {
            // Add random numbers from List to StringBuilder.
            sbNumbers.Append(number + ", ");
        }

        // Write random numbers from StringBuilder to TextBox
        txtRandomNumbers.Text = sbNumbers.ToString();
    }

6. Run the page and test the page by giving the following values in From field and To field.
From: 1
To: 10
From: 1
To: 100

Output: