Adjust screen brightness using C#

Question

How do I adjust the screen brightness in C#?

Answer 1

I tested the below code on my tablet and laptops work. You need to add a reference System.Management, find in the NuGet. This changes the actual brightness of the monitor.

//get the actual percentage of brightness
static int GetCurrentBrightness()
{
    //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();
}

Above Got from: https://www.codeproject.com/Articles/236898/Screen-Brightness-Control-for-Laptops-and-Tablets