How to simulate a click on the power button in Android with C# Xamarin?

Question

I want to write a small application so that when it starts, it starts counting for 100 seconds and then simulates a click on the power button. To send the device to sleep. How to simulate a click on the power button in Android with C# Xamarin? Thanks for advance

you might wanna take look at this: https://stackoverflow.com/questions/4545079/lock-the-android-device-programmatically — Alex, Jul 03 '19 at 12:38
Possible duplicate of [Lock the Android device programmatically](https://stackoverflow.com/questions/4545079/lock-the-android-device-programmatically) — Cheesebaron, Jul 03 '19 at 14:08

score 0 · Answer 1 · answered Jul 04 '19 at 06:20

According to your description, you want to lock screen, use the device manager DevicePolicyManager to lock screen and use PowerManager to display the screen.

inherit DeviceAdminReceiver

public class ScreenOffAdminReceiver: DeviceAdminReceiver
{
private void showToast(Context context,string msg)
{
    Toast.MakeText(context, msg, ToastLength.Short).Show();

}
public override void OnEnabled(Context context, Intent intent)
{
    base.OnEnabled(context, intent);
    showToast(context, "Device Manager enable");

}

public override void OnDisabled(Context context, Intent intent)
{
    base.OnDisabled(context, intent);
    showToast(context, "Device Manager is not enabled");

}

}

PowerManager and DevicePolicyManager

private DevicePolicyManager policyManager;
private ComponentName adminReceiver;
private PowerManager mPowerManager;
private PowerManager.WakeLock mWakeLock;


protected override void OnCreate(Bundle savedInstanceState)
{
    base.OnCreate(savedInstanceState);
    // Set our view from the "main" layout resource
    SetContentView(Resource.Layout.activity_main);



    adminReceiver= new ComponentName(this, Java.Lang.Class.FromType(typeof(ScreenOffAdminReceiver)).Name);
    policyManager = (DevicePolicyManager)GetSystemService(Context.DevicePolicyService);

    mPowerManager = (PowerManager)GetSystemService(Context.PowerService);
}

Check screen state

  private void BtncheckAndTurnOnDeviceManager_Click(object sender, System.EventArgs e)
     {
    Intent intent = new Intent(DevicePolicyManager.ActionAddDeviceAdmin);
    intent.PutExtra(DevicePolicyManager.ExtraDeviceAdmin, adminReceiver);
    intent.PutExtra(DevicePolicyManager.ExtraAddExplanation, "After you turn it on, you can use the lock screen function....");
    StartActivityForResult(intent, 0);

}

private void Btncheckscreenoff_Click(object sender, System.EventArgs e)
{
    bool admin = policyManager.IsAdminActive(adminReceiver);
    if (admin)
    {
        policyManager.LockNow();
    }
    else
    {
        showToast("No device management permissions");
    }

}

private void Btncheckscreenon_Click(object sender, System.EventArgs e)
{
    mWakeLock = mPowerManager.NewWakeLock(WakeLockFlags.Partial, "tag");
    mWakeLock.Acquire();
    mWakeLock.Release();

}

private void Btncheckscreen_Click(object sender, System.EventArgs e)
{
    PowerManager pm = (PowerManager)GetSystemService(Context.PowerService);
    bool screenOn = pm.IsScreenOn;
    if (!screenOn)
    {
        showToast("The screen is a black screen");
    }
    else
    {
        showToast("The screen is bright");

    }

}

Please confirm permission in mainifest.xml:

<uses-permission android:name="android.permission.DEVICE_POWER" />
<uses-permission android:name="android.permission.WAKE_LOCK" />

How to simulate a click on the power button in Android with C# Xamarin?

1 Answers1