android调节屏幕亮度（包括只修改应用程序和修改系统）

本文介绍在Android应用中调节屏幕亮度的方法，包括仅调整当前应用程序亮度和全局亮度调节。提供了具体的代码实现及注意事项。

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android调节屏幕亮度（包括只修改应用程序和修改系统）

本帖最后由 jairkong 于 2012-12-29 01:26 编辑

一：只改变当前程序android屏幕亮度
（1）方法：
lp.screenBrightness 取值 0.0 -- 1.0 ※设定值（float）的范围，默认小于 0（系统设定）、0.0（暗）～1.0（亮） ※调用处理的地方，例如， Activity.onCreate()等等

代码：
WindowManager.LayoutParams lp = getWindow().getAttributes();

lp.screenBrightness = 1.0f;

getWindow().setAttributes(lp);

注：1、b是一个浮点数从0~1 ，表示亮度

2、当我们遇到把Activity做为子Activity潜入到TabActivity 或者 ViewGroup 类容器时，通常上面的方法设置无法取得成功。

在子Activity中，屏幕亮度不发生改变。因为调节亮度作用域发生了改变，之前是在Activity里面对亮度修改。

而现在是作为子activity对TabActivity或ViewGroup 容器进行修改。

因此不能成功，需要通过getParent（）方法获取器Parent，然后设置。

3、

（2）恢复

当离开当前Acitivity时，屏幕亮度会恢复到原先的亮度。另外将lp.screenBrightness 设为 -1（ WindowManager.LayoutParams.BRIGHTNESS_OVERRIDE_NONE），也会让屏幕恢复到原先的亮度（即系统设置）。

（3）最小亮度

WindowManager.LayoutParams.BRIGHTNESS_OVERRIDE_NONE，官方文档说这个值可以将屏幕亮度设置到最低亮度（Lowest Brightness）。实际意识是将屏幕设置到全黑，屏幕也无法响应触控了。

在G3（CM6）上，将屏幕设置到最低亮度值是 0.004（精度0.001），这时屏幕基本全黑，但仍能控制。低于0.004（精度0.001）时，屏幕便失去控制。0.01也是个要记录的值，屏幕亮度足够低，当仍能看到东西。这些值应该是和设备有关的，不能乱设。

（4）封装进度条控制

1、封装类：

package com.cindigo.MyView;

import android.content.Context;
import android.content.SharedPreferences;
import android.graphics.Color;
import android.preference.DialogPreference;
import android.preference.PreferenceManager;
import android.util.AttributeSet;
import android.util.Log;
import android.view.Gravity;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.SeekBar;
import android.widget.TextView;

public class SeekBarPreference extends DialogPreference implements SeekBar.OnSeekBarChangeListener
{
private static final String androidns="http://schemas.android.com/apk/res/android";

public SeekBar mSeekBar;
private TextView mSplashText,mValueText;
private Context mContext;

private String mDialogMessage, mSuffix;
private int mDefault, mMax, mValue = 0,oldValue=0,preValue=0;
public SeekBarPreference(Context context, AttributeSet attrs) {
super(context,attrs);
mContext = context;
mDialogMessage = attrs.getAttributeValue(androidns,"dialogMessage");
mSuffix = attrs.getAttributeValue(androidns,"text");
mDefault = attrs.getAttributeIntValue(androidns,"defaultValue", 0);
mMax = attrs.getAttributeIntValue(androidns,"max", 100);
Log.e("SeekBarPreference", "SeekBarPreference1---"+"defaultValue:"+mDefault+"mDefault:"+mMax);
}
public SeekBarPreference(Context context, AttributeSet attrs,int defStyle) {
super(context, attrs, defStyle);
Log.e("SeekBarPreference", "SeekBarPreference2");
}

@Override
protected View onCreateDialogView() {
LinearLayout.LayoutParams params;
LinearLayout layout = new LinearLayout(mContext);
layout.setOrientation(LinearLayout.VERTICAL);
layout.setPadding(6,6,6,6);

mSplashText = new TextView(mContext);
mSplashText.setTextColor(Color.WHITE);
mSplashText.setTextSize(20);
if (mDialogMessage != null)
mSplashText.setText(mDialogMessage);
layout.addView(mSplashText);

mValueText = new TextView(mContext);
mValueText.setGravity(Gravity.CENTER_HORIZONTAL);
mValueText.setTextSize(25);
mValueText.setTextColor(Color.WHITE);
params = new LinearLayout.LayoutParams(
LinearLayout.LayoutParams.FILL_PARENT,
LinearLayout.LayoutParams.WRAP_CONTENT);
mValue = shouldPersist() ? getPersistedInt(mDefault) : 0;
if (mValueText != null){
String volum=String.valueOf(100*mValue/getMax())+"%";
mValueText.setText(mSuffix == null ? volum : mSuffix.concat(volum));
}
layout.addView(mValueText, params);

mSeekBar = new SeekBar(mContext);
//设置progressbar属性
setMax(mMax);
setProgress(mValue);
mSeekBar.setOnSeekBarChangeListen er(this);
layout.addView(mSeekBar, new LinearLayout.LayoutParams(LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.WRAP_CONTENT));
Log.e("SeekBarPreference", "onCreateDialogView---getProgress():"+getProgress()+"---Max:"+mMax);
getOldValue();//得到并保存初始值
Log.e("SeekBarPreference", "onCreateDialogView---oldValue:"+oldValue);
return layout;
}

@Override
protected void onBindDialogView(View v) {
super.onBindDialogView(v);
//设置progressbar属性
setMax(mMax);
setProgress(mValue);
Log.e("SeekBarPreference", "onBindDialogView---mValue:"+mValue);
}

@Override
protected void onSetInitialValue(boolean restore, Object defaultValue)
{
super.onSetInitialValue(restore, defaultValue);
if (restore) {
mValue = shouldPersist() ? getPersistedInt(mDefault) : 0;
Log.e("SeekBarPreference", "onSetInitialValue--true--mValue："+mValue+"mDefault："+mDefault);
}else{
mValue = (Integer)defaultValue;
Log.e("SeekBarPreference", "onSetInitialValue--false--mValue："+mValue);
}
}

public void onProgressChanged(SeekBar seek, int value, boolean fromTouch)
{
String volum=String.valueOf(100*value/getMax())+"%";
mValueText.setText(mSuffix == null ? volum : mSuffix.concat(volum));
if (shouldPersist()){
persistInt(value);
Log.d("SeekBarPreference", "onProgressChanged---onProgressChanged："+persistInt(value));
}
callChangeListener(new Integer(value));
this.mValue=value;
Log.d("SeekBarPreference", "onProgressChanged---onProgressChanged："+value);
}

@Override
public void onStartTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub
Log.e("SeekBarPreference", "onStartTrackingTouch---oldValue:"+oldValue);
}

@Override
public void onStopTrackingTouch(SeekBar seekBar) {
// TODO Auto-generated method stub
updatePreference(mValue);
notifyChanged();
Log.e("SeekBarPreference", "onStopTrackingTouch+preValue:"+getPreferenceValue()+"mvalue:"+mValue);
}

@Override
protected void onDialogClosed(boolean positiveResult) {
// TODO Auto-generated method stub
if (positiveResult) {
updatePreference(mValue);
notifyChanged();
Log.e("SeekBarPreference", "onDialogClosed--positive button---mValue："+mValue);
} else {
updatePreference(oldValue);
notifyChanged();
Log.e("SeekBarPreference", "onDialogClosed--negative button---oldValue："+oldValue);
}
}

public void setMax(int max) {
mMax = max;
if (mSeekBar != null)
mSeekBar.setMax(mMax);
}

public int getMax() {
return mMax;
}

public void setProgress(int progress) {
mValue = progress;
if (mSeekBar != null)
mSeekBar.setProgress(progress);
}

public int getProgress() {
return mValue;
}

private void updatePreference(int newValue) {
SharedPreferences.Editor editor = getEditor();
editor.putInt(getKey(), newValue);
editor.commit(); //更新 SharedPreferences 配置文件中的值
}

public int getPreferenceValue() {
if (shouldPersist()){
this.preValue= getPersistedInt(mDefault);
}
Log.e("SeekBarPreference", "getPreferenceValue---preValue:"+preValue);
return this.preValue;
}

public void getOldValue() {
this.oldValue= shouldPersist() ? getPersistedInt(mDefault) : 0;
Log.e("SeekBarPreference", "getOldValue---oldValue:"+oldValue);
}

}

2、使用：

A、在preference中直接配置：

android:dialogTitle="@string/preference_volume_dialogtitle"
android:key="preference_volume"
android:title="@string/preference_volume_title"
android:summary="@string/preference_volume_summary"
android:defaultValue="50"
android:max="100"
android:text="音量："
android:dialogMessage="请在此调节游戏音量大小："
android:layout="@layout/preference_layout_seekbar"
android:widgetLayout="@layout/preference_arrow"/>

B、代码中监听事件：

public class SettingActivity extends PreferenceActivity implements OnSharedPreferenceChange Listener {
   private SeekBarPreference sp;
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      // TODO Auto-generated method stub
      super.onCreate(savedInstanceState);
      setContentView(R.layout.buttonbar);
      addPreferencesFromResour ce(R.xml.custom_setting);
      sp= PreferenceManager.getDefaultSharedPreferen ces(this);
      sp.registerOnSharedPreferen ceChangeListener(this);//监听数据变化，调节屏幕亮度
         }
   @Override
   public void onSharedPreferenceChange d(SharedPreferences sp, String key) {
      // TODO Auto-generated method stub

         int brightness=sp.getInt("brightness", 125);
         LayoutParams lp=    getWindow().getAttributes();
         lp.screenBrightness=brightness/255.0f;
         getWindow().setAttributes(lp);

   }
}

二、全局亮度（修改手机系统亮度）
（1）说明：
Settings.System.putInt(getContentResolver(), Settings.System.SCREEN_BRIGHTNESS, bright);

可以改变全局亮度，但要让它生效可能需要，将模式改为手动

Settings.System.putInt(getContentResolver(),Settings.System.SCREEN_BRIGHTNESS_MODE, Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);

要调用这些API，需要权限：

（2）代码说明：

Android的屏幕亮度好像在2.1+的时候提供了自动调节的功能，所以，如果当开启自动调节功能的时候，我们进行调节好像是没有一点作用的，这点让我很是无语，结果只有进行判断，看是否开启了屏幕亮度的自动调节功能。

   public static boolean isAutoBrightness(ContentResolver aContentResolver) {
      boolean automicBrightness = false;
      try {
            automicBrightness = Settings.System.getInt(aContentResolver,
                  Settings.System.SCREEN_BRIGHTNESS_MODE) == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC;
      } catch (SettingNotFoundException e) {
            e.printStackTrace();
      }
      return automicBrightness;
   }

然后就是要觉得当前的亮度了，这个就比较纠结了：

   public static int getScreenBrightness(Activity activity) {
      int nowBrightnessValue = 0;
      ContentResolver resolver = activity.getContentResolver();
      try {
            nowBrightnessValue = android.provider.Settings.System.getInt(
                  resolver, Settings.System.SCREEN_BRIGHTNESS);
      } catch (Exception e) {
            e.printStackTrace();
      }
      return nowBrightnessValue;
   }

那如何修改屏幕的亮度呢？

   public static void setBrightness(Activity activity, int brightness) {
      // Settings.System.putInt(activity.getContentResolver(),
      // Settings.System.SCREEN_BRIGHTNESS_MODE,
      // Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
      WindowManager.LayoutParams lp = activity.getWindow().getAttributes();
      lp.screenBrightness = Float.valueOf(brightness) * (1f / 255f);
      activity.getWindow().setAttributes(lp);

   }

那么，能设置了，但是为什么还是会出现，设置了，没反映呢？

嘿嘿，那是因为，开启了自动调节功能了，那如何关闭呢？这才是最重要的：

   public static void stopAutoBrightness(Activity activity) {
      Settings.System.putInt(activity.getContentResolver(),
               Settings.System.SCREEN_BRIGHTNESS_MODE,
               Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
   }

能开启，那自然应该能关闭了哟哟，那怎么关闭呢？很简单的：

   public static void startAutoBrightness(Activity activity) {
      Settings.System.putInt(activity.getContentResolver(),
               Settings.System.SCREEN_BRIGHTNESS_MODE,
               Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC);
   }

至此，应该说操作亮度的差不多都有了，结束！

哎，本来认为是应该结束了，但是悲剧得是，既然像刚才那样设置的话，只能在当前的activity中有作用，一段退出的时候，会发现毫无作用，悲剧，原来是忘记了保存了。

   public static void saveBrightness(ContentResolver resolver, int brightness) {
      Uri uri = android.provider.Settings.System
               .getUriFor("screen_brightness");
      android.provider.Settings.System.putInt(resolver, "screen_brightness",
               brightness);
      // resolver.registerContentObserver(uri, true, myContentObserver);
      resolver.notifyChange(uri, null);
   }

这回该差不多了。

（3）封装：

import android.app.Activity;
import android.content.ContentResolver;
import android.content.Context;
import android.provider.Settings;
import android.provider.Settings.SettingNotFoundException;
import android.view.Window;
import android.view.WindowManager;

public class ScreenBrightnessTool
{

    public static final int ACTIVITY_BRIGHTNESS_AUTOMATIC = -1;

    public static final int SCREEN_BRIGHTNESS_MODE_AUTOMATIC = Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC;

    public static final int SCREEN_BRIGHTNESS_MODE_MANUAL = Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL;

    public static final int SCREEN_BRIGHTNESS_DEFAULT = 75;

    public static final int MAX_BRIGHTNESS = 100;

    public static final int MIN_BRIGHTNESS = 0;

    private static final int mMaxBrighrness = 255;
    private static final int mMinBrighrness = 120;

    // 当前系统调节模式
    private boolean sysAutomaticMode;
    // 当前系统亮度值
    private int sysBrightness;

    private Context context;

    private ScreenBrightnessTool(Context context, int sysBrightness,
            boolean sysAutomaticMode)
    {
        this.context = context;
        this.sysBrightness = sysBrightness;
        this.sysAutomaticMode = sysAutomaticMode;
    }


    public static ScreenBrightnessTool Builder(Context context)
    {
        int brightness;
        boolean automaticMode;
        try
        {
            // 获取当前系统亮度值
            brightness = Settings.System.getInt(context.getContentResolver(),
                    Settings.System.SCREEN_BRIGHTNESS);
            // 获取当前系统调节模式
            automaticMode = Settings.System.getInt(
                    context.getContentResolver(),
                    Settings.System.SCREEN_BRIGHTNESS_MODE) == SCREEN_BRIGHTNESS_MODE_AUTOMATIC;
        }
        catch (SettingNotFoundException e)
        {
            return null;
        }

        return new ScreenBrightnessTool(context, brightness, automaticMode);
    }


    public boolean getSystemAutomaticMode()
    {
        return sysAutomaticMode;
    }


    public int getSystemBrightness()
    {
        return sysBrightness;
    }


    public void setMode(int mode)
    {
        if (mode != SCREEN_BRIGHTNESS_MODE_AUTOMATIC
                && mode != SCREEN_BRIGHTNESS_MODE_MANUAL)
            return;

        sysAutomaticMode = mode == SCREEN_BRIGHTNESS_MODE_AUTOMATIC;
        Settings.System.putInt(context.getContentResolver(),
                Settings.System.SCREEN_BRIGHTNESS_MODE, mode);
    }


    public void setBrightness(int brightness)
    {
        int mid = mMaxBrighrness - mMinBrighrness;
        int bri = (int) (mMinBrighrness + mid * ((float) brightness)
                / MAX_BRIGHTNESS);

        ContentResolver resolver = context.getContentResolver();
        Settings.System
                .putInt(resolver, Settings.System.SCREEN_BRIGHTNESS, bri);
    }


    public static void brightnessPreview(Activity activity, float brightness)
    {
        Window window = activity.getWindow();
        WindowManager.LayoutParams lp = window.getAttributes();
        lp.screenBrightness = brightness;
        window.setAttributes(lp);
    }


    public static void brightnessPreviewFromPercent(Activity activity,
            float percent)
    {
        float brightness = percent + (1.0f - percent)
                * (((float) mMinBrighrness) / mMaxBrighrness);
        brightnessPreview(activity, brightness);
    }

}

三：更多参考：

android 关于调节屏幕亮度的问题-优快云问答Source URL:http://ask.youkuaiyun.com/questions/170

Android 调节屏幕亮度问题 - kerlubasola - ITeye技术网站Source URL:http://kerlubasola.iteye.com/blog/1581385

Android调节屏幕亮度 - android 开发专栏 - 博客频道 - youkuaiyun.comSource URL:http://blog.youkuaiyun.com/androidchuxueze/article/details/7452438

Android-Android屏幕亮度设置 - 德问:编程社交问答Source URL:http://www.dewen.org/q/2519