Android Screen Brightness 屏幕亮度 的获取和修改
Android Screen Brightness 屏幕亮度 的获取和修改
一、获取系统的屏幕亮度值
二、修改App屏幕亮度（仅当前应用）
三、修改系统屏幕亮度（所有应用）
一、获取系统的屏幕亮度值
系统屏幕亮度值在（0~255）之间，获取方法很简单，只需要调用以下方法即可。
/**
* 1.获取系统默认屏幕亮度值 屏幕亮度值范围（0-255）
* **/
private int getScreenBrightness(Context context) {
ContentResolver contentResolver = context.getContentResolver();
int defVal = 125;
return Settings.System.getInt(contentResolver,
Settings.System.SCREEN_BRIGHTNESS, defVal);
}修改屏幕亮度包含两种：
1.修改App屏幕亮度（仅当前应用）
2.修改系统屏幕亮度（所有应用）
二、修改App屏幕亮度（仅当前应用）
修改自身 APP 亮度很简单，只需要在 Activity OnCreate方法调用如下代码即可。
/**
* 2.设置 APP界面屏幕亮度值方法
* **/
private void setAppScreenBrightness(int birghtessValue) {
Window window = getWindow();
WindowManager.LayoutParams lp = window.getAttributes();
lp.screenBrightness = birghtessValue / 255.0f;
window.setAttributes(lp);
}三、修改系统屏幕亮度（所有应用）
修改系统 Settings 中的屏幕亮度，由于会影响到所有APP，需要申请修改Settings的权限
同时，需要取消光感自动调节屏幕亮度的功能，设置为手动调节模式，否则光感传感器会随着光照强度的变化修改系统屏幕亮度，并且非系统签名的APP，需要用户手动授权后才可以修改背光亮度。
关闭光感，设置手动调节背光模式实现方法如下：
/**
* 3.关闭光感，设置手动调节背光模式
*
* SCREEN_BRIGHTNESS_MODE_AUTOMATIC 自动调节屏幕亮度模式值为1
*
* SCREEN_BRIGHTNESS_MODE_MANUAL 手动调节屏幕亮度模式值为0
* **/
public void setScreenManualMode(Context context) {
ContentResolver contentResolver = context.getContentResolver();
try {
int mode = Settings.System.getInt(contentResolver,
Settings.System.SCREEN_BRIGHTNESS_MODE);
if (mode == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC) {
Settings.System.putInt(contentResolver,
Settings.System.SCREEN_BRIGHTNESS_MODE,
Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
}
} catch (Settings.SettingNotFoundException e) {
e.printStackTrace();
}
}非系统签名应用，引导用户手动授权修改Settings 权限
非系统签名应用，无法直接修改Settings,需要引导用户手动授权。
/**
* 4.非系统签名应用，引导用户手动授权修改Settings 权限
* **/
private static final int REQUEST_CODE_WRITE_SETTINGS = 1000;
private void allowModifySettings() {
// Settings.System.canWrite(MainActivity.this)
// 检测是否拥有写入系统 Settings 的权限
if (!Settings.System.canWrite(MainActivity.this)) {
AlertDialog.Builder builder = new AlertDialog.Builder(this,
android.R.style.Theme_Material_Light_Dialog_Alert);
builder.setTitle("请开启修改屏幕亮度权限");
builder.setMessage("请点击允许开启");
// 拒绝, 无法修改
builder.setNegativeButton("拒绝",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(MainActivity.this,
"您已拒绝修系统Setting的屏幕亮度权限", Toast.LENGTH_SHORT)
.show();
}
});
builder.setPositiveButton("去开启",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// 打开允许修改Setting 权限的界面
Intent intent = new Intent(
Settings.ACTION_MANAGE_WRITE_SETTINGS, Uri
.parse("package:"
+ getPackageName()));
startActivityForResult(intent,
REQUEST_CODE_WRITE_SETTINGS);
}
});
builder.setCancelable(false);
builder.show();
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == REQUEST_CODE_WRITE_SETTINGS) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
// Settings.System.canWrite方法检测授权结果
if (Settings.System.canWrite(getApplicationContext())) {
// 5.调用修改Settings屏幕亮度的方法 屏幕亮度值 200
ModifySettingsScreenBrightness(MainActivity.this, 200);
Toast.makeText(this, "系统屏幕亮度值" + getScreenBrightness(this),
Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(MainActivity.this, "您已拒绝修系统Setting的屏幕亮度权限",
Toast.LENGTH_SHORT).show();
}
}
}
}
修改Setting 中屏幕亮度值 实现
拥有系统签名的应用可以直接调用此方法修改系统屏幕亮度，非系统签名应用，只有用户授权后才可以修改。
/**
* 5.修改Setting 中屏幕亮度值
*
* 修改Setting的值需要动态申请权限 整体实现如下：
package com.example.test;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.ContentResolver;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Build;
import android.os.Bundle;
import android.provider.Settings;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Toast;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//获取屏幕亮度
getScreenBrightness(this);
Toast.makeText(this, "系统屏幕亮度值" + getScreenBrightness(this),
Toast.LENGTH_SHORT).show();
// 设置APP 屏幕亮度后，系统Setting亮度将对此app 不生效
setAppScreenBrightness(100);
allowModifySettings();
setContentView(R.layout.activity_main);
}
/**
* 1.获取系统默认屏幕亮度值 屏幕亮度值范围（0-255）
* **/
private int getScreenBrightness(Context context) {
ContentResolver contentResolver = context.getContentResolver();
int defVal = 125;
return Settings.System.getInt(contentResolver,
Settings.System.SCREEN_BRIGHTNESS, defVal);
}
/**
* 2.设置 APP界面屏幕亮度值方法
* **/
private void setAppScreenBrightness(int birghtessValue) {
Window window = getWindow();
WindowManager.LayoutParams lp = window.getAttributes();
lp.screenBrightness = birghtessValue / 255.0f;
window.setAttributes(lp);
}
/**
* 3.关闭光感，设置手动调节背光模式
*
* SCREEN_BRIGHTNESS_MODE_AUTOMATIC 自动调节屏幕亮度模式值为1
*
* SCREEN_BRIGHTNESS_MODE_MANUAL 手动调节屏幕亮度模式值为0
* **/
public void setScreenManualMode(Context context) {
ContentResolver contentResolver = context.getContentResolver();
try {
int mode = Settings.System.getInt(contentResolver,
Settings.System.SCREEN_BRIGHTNESS_MODE);
if (mode == Settings.System.SCREEN_BRIGHTNESS_MODE_AUTOMATIC) {
Settings.System.putInt(contentResolver,
Settings.System.SCREEN_BRIGHTNESS_MODE,
Settings.System.SCREEN_BRIGHTNESS_MODE_MANUAL);
}
} catch (Settings.SettingNotFoundException e) {
e.printStackTrace();
}
}
/**
* 4.非系统签名应用，引导用户手动授权修改Settings 权限
* **/
private static final int REQUEST_CODE_WRITE_SETTINGS = 1000;
private void allowModifySettings() {
// Settings.System.canWrite(MainActivity.this)
// 检测是否拥有写入系统 Settings 的权限
if (!Settings.System.canWrite(MainActivity.this)) {
AlertDialog.Builder builder = new AlertDialog.Builder(this,
android.R.style.Theme_Material_Light_Dialog_Alert);
builder.setTitle("请开启修改屏幕亮度权限");
builder.setMessage("请点击允许开启");
// 拒绝, 无法修改
builder.setNegativeButton("拒绝",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(MainActivity.this,
"您已拒绝修系统Setting的屏幕亮度权限", Toast.LENGTH_SHORT)
.show();
}
});
builder.setPositiveButton("去开启",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// 打开允许修改Setting 权限的界面
Intent intent = new Intent(
Settings.ACTION_MANAGE_WRITE_SETTINGS, Uri
.parse("package:"
+ getPackageName()));
startActivityForResult(intent,
REQUEST_CODE_WRITE_SETTINGS);
}
});
builder.setCancelable(false);
builder.show();
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == REQUEST_CODE_WRITE_SETTINGS) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
// Settings.System.canWrite方法检测授权结果
if (Settings.System.canWrite(getApplicationContext())) {
// 5.调用修改Settings屏幕亮度的方法 屏幕亮度值 200
ModifySettingsScreenBrightness(MainActivity.this, 200);
Toast.makeText(this, "系统屏幕亮度值" + getScreenBrightness(this),
Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(MainActivity.this, "您已拒绝修系统Setting的屏幕亮度权限",
Toast.LENGTH_SHORT).show();
}
}
}
}
/**
* 5.修改Setting 中屏幕亮度值
*
* 修改Setting的值需要动态申请权限