问题
I am trying to turn on and off the display after a certain action happens (Lets just worry about turning the screen off for now). From what I understand from wake lock, this is what I have:
PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
PowerManager.WakeLock wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "My Tag");
When I read other posts on stackoverflow and else where, they seem to tell me that PARTIAL_WAKE_LOCK will turn the screen off. But if I read the SDK it says that it will only allow the screen to be turned off. So I think this isn't right.
Any hints would be helpful! Thanks,
Mike
回答1:
There are two choices for turning the screen off:
PowerManager manager = (PowerManager) getSystemService(Context.POWER_SERVICE);
// Choice 1
manager.goToSleep(int amountOfTime);
// Choice 2
PowerManager.WakeLock wl = manager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "Your Tag");
wl.acquire();
wl.release();
You will probably need this permission too:
<uses-permission android:name="android.permission.WAKE_LOCK" />
UPDATE:
Try this method; android turns off the screen once the light level is low enough.
WindowManager.LayoutParams params = getWindow().getAttributes();
params.flags |= LayoutParams.FLAG_KEEP_SCREEN_ON;
params.screenBrightness = 0;
getWindow().setAttributes(params);
回答2:
The following is copied from SDK document.
If you want to keep screen on, I think SCREEN_BRIGHT_WAKE_LOCK
is enough.
Flag Value CPU Screen Keyboard
PARTIAL_WAKE_LOCK On* Off Off
SCREEN_DIM_WAKE_LOCK On Dim Off
SCREEN_BRIGHT_WAKE_LOCK On Bright Off
FULL_WAKE_LOCK On Bright Bright
回答3:
For me those methods didn't work. So I used other scenario (not trivial) to make my screen off.
Android has 2 flags that responsible to be awake:
- Display --> Screen TimeOut
- Application --> Development --> Stay awake while charging check box.
I used followed flow:
1st of all save your previous configuration, for example screen timeout was 1 min and Stay awake while charging checked.
After, I uncheck Stay awake while charging and set screen timeout to minimal time.
I register to broadcast receiver service to get event from android that screen turned off.
When I got event on screen off, I set previous configuration to default: screen timeout was 1 min and Stay awake while charging checked.
Unregister receiver
After 15 sec. device sleeps
Here is snippets of code:
BroadcastReceiver
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
/**
* Catch Screen On/Off
* */
public class BroadcastReceiverScreenListener extends BroadcastReceiver{
private BroadCastListenerCallBackItf mBroadCastListenerCallBack = null;
public BroadcastReceiverScreenListener(
BroadCastListenerCallBackItf broadCastListenerCallBack) {
this.mBroadCastListenerCallBack = broadCastListenerCallBack;
}
@Override
public void onReceive(Context arg0, Intent intent) {
if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
mBroadCastListenerCallBack.broadCastListenerCallBack__ScreenOff_onResponse();
}
}
}
Interface used as callback
public interface BroadCastListenerCallBackItf {
public void broadCastListenerCallBack__ScreenOff_onResponse();
}
2 methods from main class:
....
AndroidSynchronize mSync = new AndroidSynchronize();
....
public void turnScreenOff(int wait){
IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
filter.addAction(Intent.ACTION_SCREEN_OFF);
BroadCastListenerCallBackItf broadCastListenerCallBack = this;
BroadcastReceiver mReceiver = new BroadcastReceiverScreenListener(broadCastListenerCallBack);
m_context.registerReceiver(mReceiver, filter);
//set Development --> disable STAY_ON_WHILE_PLUGGED_IN
Settings.System.putInt(
m_context.getContentResolver(),
Settings.System.STAY_ON_WHILE_PLUGGED_IN,
0 );
// take current screen off time
int defTimeOut = Settings.System.getInt(m_context.getContentResolver(),
Settings.System.SCREEN_OFF_TIMEOUT, 3000);
// set 15 sec
Settings.System.putInt(m_context.getContentResolver(),
Settings.System.SCREEN_OFF_TIMEOUT, 15000);
// wait 200 sec till get response from BroadcastReceiver on Screen Off
mSync.doWait(wait*1000);
// set previous settings
Settings.System.putInt(m_context.getContentResolver(),
Settings.System.SCREEN_OFF_TIMEOUT, defTimeOut);
// switch back previous state
Settings.System.putInt(
m_context.getContentResolver(),
Settings.System.STAY_ON_WHILE_PLUGGED_IN,
BatteryManager.BATTERY_PLUGGED_USB);
m_context.unregisterReceiver(mReceiver);
}
public void broadCastListenerCallBack__ScreenOff_onResponse() {
mSync.doNotify();
}
....
AndroidSynchronize class
public class AndroidSynchronize {
public void doWait(long l){
synchronized(this){
try {
this.wait(l);
} catch(InterruptedException e) {
}
}
}
public void doNotify() {
synchronized(this) {
this.notify();
}
}
public void doWait() {
synchronized(this){
try {
this.wait();
} catch(InterruptedException e) {
}
}
}
}
[EDIT]
You need to register permission:
android.permission.WRITE_SETTINGS
回答4:
Per this link, You can also turn the screen off like this:
Settings.System.putInt(getContentResolver(), Settings.System.SCREEN_OFF_TIMEOUT, 1000);
1000 is in milliseconds which means 1 second, you can replace it with any value as desired.
Needed permission:
<uses-permission android:name="android.permission.WRITE_SETTINGS" />
回答5:
try - wakeLock.acquire(1000); // specify the time , it dims out and eventually turns off.
来源:https://stackoverflow.com/questions/6756768/turn-off-screen-on-android