 using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace LoginDemo
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            guna2ShadowForm1.SetShadowForm(this);
            this.Load += Form1_Load;
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            this.BeginInvoke(new Action(() =>
            {
                //if (string.IsNullOrEmpty(Properties.Settings.Default.username))
                //{
                    txtUsername.Text = Properties.Settings.Default.username;
                    txtPassword.Text = Properties.Settings.Default.password;
                chkRemember.Checked = Properties.Settings.Default.isRemember;
                //}
            }));
           
        }

        private void btnLogin_Click(object sender, EventArgs e)
        {
            var username = txtUsername.Text.Trim();
            var password = txtPassword.Text.Trim();

            if (string.IsNullOrEmpty(username))
            {
                MessageBox.Show("Enter your username");
                txtUsername.Focus();
                return;
            }

            if (string.IsNullOrEmpty(password))
            {
                MessageBox.Show("Enter your my password");
                txtPassword.Focus();
                return;
            }

            var sql = $"select count(*) from tbl_users where username='{username}' and password='{GetMD5(password)}'";

            var isLogin = Convert.ToInt32(SQLHelper.ExecQuerySacalar(sql)) > 0 ? true : false;
            if (isLogin)
            {
                //MessageBox.Show("Login Successful!");
                if (chkRemember.Checked)
                {
                    Properties.Settings.Default.username = username;
                    Properties.Settings.Default.password = password;
                    Properties.Settings.Default.isRemember = true;
                    
                    Properties.Settings.Default.Save();
                    Properties.Settings.Default.Upgrade();
                }
                else
                {
                    Properties.Settings.Default.username = "";
                    Properties.Settings.Default.password = "";
                    Properties.Settings.Default.isRemember = false;
                    Properties.Settings.Default.Save();
                    Properties.Settings.Default.Upgrade();
                }
              
                var frmMain = new FrmMain(username);
                frmMain.Show();
                this.Hide();
            }
            else
            {
                MessageBox.Show("Username or password wrong!");
            }

        }

        private String GetMD5(string txt)
        {
            String str = "";
            Byte[] buffer = System.Text.Encoding.UTF8.GetBytes(txt);
            System.Security.Cryptography.MD5CryptoServiceProvider md5 = new System.Security.Cryptography.MD5CryptoServiceProvider();
            buffer = md5.ComputeHash(buffer);
            foreach (Byte b in buffer)
            {
                str += b.ToString("X2");
            }
            return str;
        }
    }
}

created 3 years ago

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 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

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
}