Android 获取及修改屏幕亮度_android 调节屏幕亮度

前言：

1.获取当前系统屏幕亮度

2.修改app屏幕亮度，仅对当前app有效。-可用在出示二维码界面，需要单个界面提高亮度时使用

3.修改系统屏幕亮度，所有app有效。Android 6.0 以上需要动态申请权限

实现：

1.权限

<uses-permission android:name="android.permission.WRITE_SETTINGS"
    tools:ignore="ProtectedPermissions" />

2.动态申请

 /**
     * 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;
 
    @RequiresApi(api = Build.VERSION_CODES.M)
    private void initPermission() {
        // Settings.System.canWrite(MainActivity.this)
        // 检测是否拥有写入系统 Settings 的权限
        if (!Settings.System.canWrite(MainActivity5.this)) {
            AlertDialog.Builder builder = new AlertDialog.Builder(this);
            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(MainActivity5.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, @Nullable Intent data) {
        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())) {
                    //授权通过
                } else {
                    Toast.makeText(MainActivity5.this, "您已拒绝修系统Setting的屏幕亮度权限",
                            Toast.LENGTH_SHORT).show();
                }
            }
        }
    }

3.获取系统屏幕亮度（如果不需要修改系统屏幕亮度的话不需要申请权限）

    /**
     * 获取app屏幕亮度
     *
     * @param activity
     * @return
     */
    public static int getScreenBrightness(Activity activity) {
        int value = 0;
        ContentResolver cr = activity.getContentResolver();
        try {
            value = Settings.System.getInt(cr, Settings.System.SCREEN_BRIGHTNESS);
        } catch (Settings.SettingNotFoundException e) {
        }
        return value;
    }

4.设置app屏幕亮度（仅对当前app有效，不需要申请权限）

/**
     * 设置app屏幕亮度
     *
     * @param activity
     * @param value
     */
    public static void setScreenBrightness(Activity activity, int value) {
        WindowManager.LayoutParams params = activity.getWindow().getAttributes();
        params.screenBrightness = value / 255f;
        activity.getWindow().setAttributes(params);
    }

5.修改系统屏幕亮度（Android 6.0 以上必须动态申请权限）

findViewById(R.id.mBtn_set_system).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //关闭光感
                setScreenManualMode(MainActivity5.this);
                //设置系统屏幕亮度
                ModifySettingsScreenBrightness(MainActivity5.this, 100);
            }
        });
 
    /**
     * 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();
        }
    }
 
    /**
     * 修改Setting 中屏幕亮度值  亮度   0-255
     * 修改Setting的值需要动态申请权限 <uses-permission
     * android:name="android.permission.WRITE_SETTINGS"/>
     **/
    private void ModifySettingsScreenBrightness(Context context, int birghtessValue) {
        // 首先需要设置为手动调节屏幕亮度模式
        setScreenManualMode(context);
        ContentResolver contentResolver = context.getContentResolver();
        Settings.System.putInt(contentResolver, Settings.System.SCREEN_BRIGHTNESS, birghtessValue);
    }