Dashboard/Dashboard/Form1.cs

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;
using System.Runtime.InteropServices;

namespace Dashboard
{
    public partial class Form1 : Form
    {

        [DllImport("Gdi32.dll", EntryPoint = "CreateRoundRectRgn")]

        private static extern IntPtr CreateRoundRectRgn
         (
               int nLeftRect,
               int nTopRect,
               int nRightRect,
               int nBottomRect,
               int nWidthEllipse,
               int nHeightEllipse

         );

        public Form1()
        {
            InitializeComponent();
            Region = System.Drawing.Region.FromHrgn(CreateRoundRectRgn(0, 0, Width, Height, 25, 25));
            pnlNav.Height = btnDashbord.Height;
            pnlNav.Top = btnDashbord.Top;
            pnlNav.Left = btnDashbord.Left;

            lbltitle.Text = "Dashbord";
            frmDashboard frmDashboard_vrb = new frmDashboard() { Dock = DockStyle.Fill, TopLevel = false, TopMost = true };
            frmDashboard_vrb.FormBorderStyle = FormBorderStyle.None;
            this.pnlFormLoader.Controls.Add(frmDashboard_vrb);
            frmDashboard_vrb.Show();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void btnDashbord_Click(object sender, EventArgs e)
        {
            pnlNav.Height = btnDashbord.Height;
            pnlNav.Top = btnDashbord.Top;
            pnlNav.Left = btnDashbord.Left;
            btnDashbord.BackColor = Color.FromArgb(46, 51, 73);

            lbltitle.Text = "Dashbord";
            this.pnlFormLoader.Controls.Clear();
            frmDashboard frmDashboard_vrb = new frmDashboard() { Dock = DockStyle.Fill, TopLevel = false, TopMost = true };
            frmDashboard_vrb.FormBorderStyle = FormBorderStyle.None;
            this.pnlFormLoader.Controls.Add(frmDashboard_vrb);
            frmDashboard_vrb.Show();

        }

        private void btnAnalytics_Click(object sender, EventArgs e)
        {
            pnlNav.Height = btnAnalytics.Height;
            pnlNav.Top = btnAnalytics.Top;
            btnAnalytics.BackColor = Color.FromArgb(46, 51, 73);

            lbltitle.Text = "Analytics";
            this.pnlFormLoader.Controls.Clear();
            frmAnalytics frmAnalytics_vrb = new frmAnalytics() { Dock = DockStyle.Fill, TopLevel = false, TopMost = true };
            frmAnalytics_vrb.FormBorderStyle = FormBorderStyle.None;
            this.pnlFormLoader.Controls.Add(frmAnalytics_vrb);
            frmAnalytics_vrb.Show();
        }

        private void btnCalender_Click(object sender, EventArgs e)
        {
            pnlNav.Height = btnCalender.Height;
            pnlNav.Top = btnCalender.Top;
            btnCalender.BackColor = Color.FromArgb(46, 51, 73);

            this.pnlFormLoader.Controls.Clear();
            frmCalender frmCalender_vrb = new frmCalender() { Dock = DockStyle.Fill, TopLevel = false, TopMost = true };
            frmCalender_vrb.FormBorderStyle = FormBorderStyle.None;
            this.pnlFormLoader.Controls.Add(frmCalender_vrb);
            frmCalender_vrb.Show();
            lbltitle.Text = "Calender";
        }

        private void btnContactUs_Click(object sender, EventArgs e)
        {
            pnlNav.Height = btnContactUs.Height;
            pnlNav.Top = btnContactUs.Top;
            btnContactUs.BackColor = Color.FromArgb(46, 51, 73);

            this.pnlFormLoader.Controls.Clear();
            frmContactUs frmContactUs_vrb = new frmContactUs() { Dock = DockStyle.Fill, TopLevel = false, TopMost = true };
            frmContactUs_vrb.FormBorderStyle = FormBorderStyle.None;
            this.pnlFormLoader.Controls.Add(frmContactUs_vrb);
            frmContactUs_vrb.Show();
            lbltitle.Text = "Contact Us";
        }

        private void btnsettings_Click(object sender, EventArgs e)
        {
            pnlNav.Height = btnsettings.Height;
            pnlNav.Top = btnsettings.Top;
            btnsettings.BackColor = Color.FromArgb(46, 51, 73);

            this.pnlFormLoader.Controls.Clear();
            frmSettings frmSettings_vrb = new frmSettings() { Dock = DockStyle.Fill, TopLevel = false, TopMost = true };
            frmSettings_vrb.FormBorderStyle = FormBorderStyle.None;
            this.pnlFormLoader.Controls.Add(frmSettings_vrb);
            frmSettings_vrb.Show();
            lbltitle.Text = "Settings";
        }

        private void btnDashbord_Leave(object sender, EventArgs e)
        {
            btnDashbord.BackColor = Color.FromArgb(24, 30, 54);
        }

        private void btnAnalytics_Leave(object sender, EventArgs e)
        {
            btnAnalytics.BackColor = Color.FromArgb(24, 30, 54);
        }

        private void btnCalender_Leave(object sender, EventArgs e)
        {
            btnCalender.BackColor = Color.FromArgb(24, 30, 54);
        }

        private void btnContactUs_Leave(object sender, EventArgs e)
        {
            btnContactUs.BackColor = Color.FromArgb(24, 30, 54);
        }

        private void btnsettings_Leave(object sender, EventArgs e)
        {
            btnsettings.BackColor = Color.FromArgb(24, 30, 54);
        }

        private void button1_Click_1(object sender, EventArgs e)
        {
            Application.Exit();
        }

        private void panel3_Paint(object sender, PaintEventArgs e)
        {

        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            textBox1.Clear();
        }

        private void textBox1_Leave(object sender, EventArgs e)
        {

        }
    }
}