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 = ""; } } }
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.
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);
}
}
}
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.
Data Type | Description | Range | size |
---|---|---|---|
int | To store integers | -2,147,483,648 to 2,147,483,647 | 4 bytes |
double | to store large floating point numbers with decimals | can store 15 decimal digits | 8 bytes |
float | to store floating point numbers with decimals | can store upto 7 decimal digits | 4 bytes |
char | to store single characters | - | 2 bytes |
string | to stores text | - | 2 bytes per character |
bool | to stores either true or false | - | 1 bit |
datatype variable-name = value;
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.
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;
}
For loop is used to iterate a set of statements based on a condition.
for(Initialization; Condition; Increment/decrement) {
// code
}
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
}
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);
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.
data-type[] array-name;
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.
static void method-name()
{
// code to be executed
}