Xin chào các bạn, bài viết hôm nay mình sẽ tiếp tục chia sẽ đến các bạn một ứng dụng nhỏ dùng để thay đổi độ sáng tối của màn hình Laptop trong lập trình c# winform.

[C#] Tutorial Change Screen Brightness Winform

Dưới đây là giao diện ứng dụng:

Ở giao diện hình trên, các bạn thấy mình có một trackbar, dùng để thay đổi phần trăm độ sáng tối (Brightness screen) của màn hình.

Lưu ý: ứng dụng chỉ hỗ trợ chạy trên Laptop thôi nhé các bạn.

Source code Screen Brightness C#

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

namespace ScreenBrightness
{
    public partial class Form1 : Form
    {
        int iCount = 0; //global counter for hiding/closing form after certian period of inactivity
        byte[] bLevels; //array of valid level values
        string[] arguments; 

        public Form1(string[]args)
        {
            arguments = args;
            InitializeComponent();
        }

        //In case of an incompatible system, the form has to be shown in order to close the app...as far as I know ^^
        private void Form1_Shown(object sender, EventArgs e)
        {
            bLevels = GetBrightnessLevels(); //get the level array for this system
            if (bLevels.Count() == 0) //"WmiMonitorBrightness" is not supported by the system
            {
                Application.Exit();
            }
            else
            {
                trackBar1.TickFrequency = bLevels.Count(); //adjust the trackbar ticks according the number of possible brightness levels
                trackBar1.Maximum = bLevels.Count() - 1;
                trackBar1.Update();
                trackBar1.Refresh();
                check_brightness();
                timer1.Enabled = true;  //timer for closing form
                //check the arguments
                if (Array.FindIndex(arguments, item => item.Contains("%") ) > -1)
                    startup_brightness();
                if (arguments.Length == 0 || Array.IndexOf(arguments, "hide")>-1) //hide the trackbar initially if no arguments are passed
                    this.Hide();

            }
        }
        private void check_brightness()
        {
                int iBrightness = GetBrightness(); //get the actual value of brightness
                int i = Array.IndexOf(bLevels, (byte)iBrightness); 
                if (i < 0) i = 1;
                change_icon(iBrightness); 
                trackBar1.Value = i;
        }

        private void startup_brightness()
        {
            string sPercent = arguments[Array.FindIndex(arguments, item => item.Contains("%"))];
            if (sPercent.Length > 1)
            {
                int iPercent = Convert.ToInt16(sPercent.Split('%').ElementAt(0));
                if (iPercent >= 0 && iPercent <= bLevels[bLevels.Count() - 1])
                {
                    byte level =100;
                    foreach (byte item in bLevels)
                    {
                        if (item >= iPercent)
                        {
                            level = item;
                            break;
                        }
                    }
                    SetBrightness(level);
                    check_brightness();
                }
                    
            }
        }

        //change the icon according to brightness
        private void change_icon(int iBrightness)
        {
            if (iBrightness < 25)  
                pictureBox1.Image = ScreenBrightness.Properties.Resources.sonne_2;
            else
            {
                if (iBrightness < 75)
                    pictureBox1.Image = ScreenBrightness.Properties.Resources.sonne_1;
                else
                    pictureBox1.Image = ScreenBrightness.Properties.Resources.sonne;
            }
            label1.Text = iBrightness.ToString() + "%";
        }

        private void trackBar1_Scroll(object sender, EventArgs e)
        {
            SetBrightness(bLevels[trackBar1.Value]);
            change_icon(bLevels[trackBar1.Value]);
            iCount = 0; //reset inactivity counter
        }



        //get the actual percentage of brightness
        static int GetBrightness()
        {
            //define scope (namespace)
            System.Management.ManagementScope s = new System.Management.ManagementScope("root\\WMI");

            //define query
            System.Management.SelectQuery q = new System.Management.SelectQuery("WmiMonitorBrightness");

            //output current brightness
            System.Management.ManagementObjectSearcher mos = new System.Management.ManagementObjectSearcher(s, q);

            System.Management.ManagementObjectCollection moc = mos.Get();

            //store result
            byte curBrightness = 0;
            foreach (System.Management.ManagementObject o in moc)
            {
                curBrightness = (byte)o.GetPropertyValue("CurrentBrightness");
                break; //only work on the first object
            }

            moc.Dispose();
            mos.Dispose();

            return (int)curBrightness;
        }

        //array of valid brightness values in percent
        static byte[] GetBrightnessLevels()
        {
            //define scope (namespace)
            System.Management.ManagementScope s = new System.Management.ManagementScope("root\\WMI");

            //define query
            System.Management.SelectQuery q = new System.Management.SelectQuery("WmiMonitorBrightness");

            //output current brightness
            System.Management.ManagementObjectSearcher mos = new System.Management.ManagementObjectSearcher(s, q);
            byte[] BrightnessLevels = new byte[0];

            try
            {
                System.Management.ManagementObjectCollection moc = mos.Get();

                    //store result
 

                foreach (System.Management.ManagementObject o in moc)
                {
                    BrightnessLevels = (byte[])o.GetPropertyValue("Level");
                    break; //only work on the first object
                }

                moc.Dispose();
                mos.Dispose();

            }
            catch (Exception)
            {
                MessageBox.Show("Sorry, Your System does not support this brightness control...");
                
            }

            return BrightnessLevels;
        }

        static void SetBrightness(byte targetBrightness)
        {
            //define scope (namespace)
            System.Management.ManagementScope s = new System.Management.ManagementScope("root\\WMI");

            //define query
            System.Management.SelectQuery q = new System.Management.SelectQuery("WmiMonitorBrightnessMethods");

            //output current brightness
            System.Management.ManagementObjectSearcher mos = new System.Management.ManagementObjectSearcher(s, q);

            System.Management.ManagementObjectCollection moc = mos.Get();

            foreach (System.Management.ManagementObject o in moc)
            {
                o.InvokeMethod("WmiSetBrightness", new Object[] { UInt32.MaxValue, targetBrightness }); //note the reversed order - won't work otherwise!
                break; //only work on the first object
            }

            moc.Dispose();
            mos.Dispose();
        }

        //timer for hiding/closing form
        private void timer1_Tick(object sender, EventArgs e)
        {
            iCount++;
            if(iCount > 2)
            {
                if (Array.IndexOf(arguments, "quit") > -1)
                    this.Close();
                else
                {
                    this.Hide();
                    timer1.Stop();
                    iCount = 0;
                }

            }
        }

        private void notifyIcon1_MouseDoubleClick(object sender, MouseEventArgs e)
        {
            if (e.Button == System.Windows.Forms.MouseButtons.Left)
            {
                Point p = new Point(MousePosition.X, MousePosition.Y);
                Rectangle r = Screen.GetBounds(p);
                //find the right position next to the icon
                if (p.X > r.Width / 2)
                {
                    if (p.X + 140 > r.Width)
                        this.Left = r.Width - 275;
                    else
                        this.Left = p.X - 140;
                }
                else
                    this.Left = p.X;

                if (p.Y > r.Height / 2)
                    this.Top = p.Y - 60;
                else
                    this.Top = p.Y;
                check_brightness();
                this.Show();
                this.Activate();
                timer1.Start();
            }
            else
                contextMenuStrip1.Show(MousePosition.X, MousePosition.Y);
           
        }

        private void exitToolStripMenuItem_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        private void notifyIcon1_MouseMove(object sender, MouseEventArgs e)
        {
            notifyIcon1.Text = "screen brightness " + GetBrightness().ToString() + "%";
        }

    }
}

Thanks for watching!

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