using System; 
using System.Data; 
using System.Data.SqlClient; 
using System.Windows.Forms; 
  
namespace WinFormsApp1 {
     public partial class Form1 : Form
     {
         String connectionString = @"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\kmahe\source\repos\WinFormsApp1\W inFormsApp1\Database1.mdf;Integrated Security=True"; 
 
        public Form1()
         {
             InitializeComponent();
         }
        private void button2_Click(object sender, EventArgs e)
         {
             panel1.BringToFront();
         }
         private void button1_Click(object sender, EventArgs e)
         {
             if (textBox1.Text != string.Empty || textBox2.Text != string.Empty)
             {
                // string name = textBox1.Text;
                 //string Password = textBox2.Text;
                 SqlConnection con = new SqlConnection(connectionString);
                 con.Open();
                 String query = "Select * from Table_1 where std_name ='" + textBox1.Text + "' and Password = '" + textBox2.Text + "'";
                 SqlCommand cmd = new SqlCommand(query, con);
                 cmd.Connection = con;
                 int i = Convert.ToInt32(cmd.ExecuteScalar());
                           if (i > 0)
                     {
                         this.Hide();
                         Form2 form2 = new Form2();
                         form2.ShowDialog();
                     }
                     else
                      {
                             MessageBox.Show("Login Failed!!!");
                     }
                     con.Close();
             }
             else
             {
                 MessageBox.Show("Please Enter details");
                 return;
             } 
        } 
 
        private void button3_Click(object sender, EventArgs e)
         {
             panel2.BringToFront();
         }
         private void Form1_Load(object sender, EventArgs e)
         {
             button3.PerformClick();
              }
         private void button4_Click(object sender, EventArgs e)
         {
                   if (textBox3.Text != string.Empty || textBox4.Text != string.Empty || textBox5.Text != string.Empty|| textBox6.Text != string.Empty|| textBox7.Text != string.Empty)
             {
                 String id = textBox3.Text;
                 String std_name = textBox4.Text;
                 String std_class = textBox5.Text;
                 String branch_id = textBox6.Text;
                 String password = textBox7.Text;
                 SqlConnection con = new SqlConnection(connectionString);
                 con.Open();
                 String query = "INSERT INTO Table_1 (id,std_name,Class,branch_id,password) VALUES ('" + id + "','" + std_name + "','" + std_class + "','" + branch_id + "','" + password + "')";
                 SqlCommand cmd = new SqlCommand(query, con);
                 int i = cmd.ExecuteNonQuery();
                 if (i > 0)
                 {
                     MessageBox.Show("Registered");
                     ClearData();
                 }
                 else if (i == 0)
                 {
                     MessageBox.Show("Not Registered");
                 }
               con.Close();
             }
             else
             {
                 MessageBox.Show("Please Enter Data");
                 return;
             }
         }

         //Clear data after submit
         private void ClearData()
         {
             textBox3.Text = "";
             textBox6.Text = "";
             textBox5.Text = "";
             textBox4.Text = "";
             textBox7.Text = ""; 
 
        }
     }
 }
 

C Sharp Online Compiler

Write, Run & Share C# code online using OneCompiler's C# online compiler for free. It's one of the robust, feature-rich online compilers for C# language, running on the latest version 8.0. Getting started with the OneCompiler's C# compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C# and start coding.

Read inputs from stdin

OneCompiler's C# online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.

using System;
 
namespace Sample
{
  class Test
    {
      public static void Main(string[] args)
       {
         string name;
         name = Console.ReadLine();
         Console.WriteLine("Hello {0} ", name);
	}
     }
}

About C Sharp

C# is a general purpose object-oriented programming language by Microsoft. Though initially it was developed as part of .net but later it was approved by ECMA and ISO standards.

You can use C# to create variety of applications, like web, windows, mobile, console applications and much more using Visual studio.

Syntax help

Data types

Data TypeDescriptionRangesize
intTo store integers-2,147,483,648 to 2,147,483,6474 bytes
doubleto store large floating point numbers with decimalscan store 15 decimal digits8 bytes
floatto store floating point numbers with decimalscan store upto 7 decimal digits4 bytes
charto store single characters-2 bytes
stringto stores text-2 bytes per character
boolto stores either true or false-1 bit

Variables

Syntax

datatype variable-name = value;

Loops

1. If-Else:

When ever you want to perform a set of operations based on a condition or set of few conditions IF-ELSE is used.

if(conditional-expression) {
   // code
} 
else {
   // code
}

You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.

2. Switch:

Switch is an alternative to If-Else-If ladder.

switch(conditional-expression) {    
case value1:    
 // code    
 break;  // optional  
case value2:    
 // code    
 break;  // optional  
...    
    
default:     
 // code to be executed when all the above cases are not matched;    
} 

3. For:

For loop is used to iterate a set of statements based on a condition.

for(Initialization; Condition; Increment/decrement) {
  // code  
} 

4. While:

While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.

while(condition) {
 // code 
}

5. Do-While:

Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.

do {
  // code 
} while (condition);

Arrays

Array is a collection of similar data which is stored in continuous memory addresses. Array values can be fetched using index. Index starts from 0 to size-1.

Syntax

data-type[] array-name;

Methods

Method is a set of statements which gets executed only when they are called. Call the method name in the main function to execute the method.

Syntax

static void method-name() 
{
  // code to be executed
}