调整屏幕显示亮度

使用SeekBar控件来控制

布局文件：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
                xmlns:tools="http://schemas.android.com/tools"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical"
                tools:context=".MainActivity">

    <!-- 拖拽实现控制屏幕亮度-->
    <SeekBar
            android:id="@+id/brightness_bar"
            android:layout_width="400dp"
            android:layout_height="wrap_content"
            />
</LinearLayout>

Activity代码

1.设置SeekBar控件

SeekBar bar = (SeekBar) findViewById(R.id.brightness_bar);
        bar.setOnSeekBarChangeListener(this);

2.继承 SeekBar.OnSeekBarChangeListener 接口

实现三个方法

@Override
    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
        int id = seekBar.getId();
        Window window = getWindow();
        switch (id){
            //调整屏幕的亮度
            case R.id.brightness_bar:
                WindowManager.LayoutParams attributes = window.getAttributes();
                attributes.screenBrightness = (float) (progress * 0.01);
                window.setAttributes(attributes);
                break;
        }
    }

    @Override
    public void onStartTrackingTouch(SeekBar seekBar) {
    }

    @Override
    public void onStopTrackingTouch(SeekBar seekBar) {
    }