[移动开发]android调节当前屏幕亮度；获取系统屏幕亮度；seekbar拖动条

android调节当前屏幕亮度；获取系统屏幕亮度；seekbar拖动条

1、效果图

2、布局文件

<?xml version="1.0" encoding="utf-8"?>
<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"
    android:layout_marginTop="15dp"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="TextView"/>
    <SeekBar
        android:id="@+id/seekBar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="20dp" />

</LinearLayout>

3、工具类

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

public class BrightnessUtil {

    /**
     *获取系统当前屏幕亮度
     */
    public static int getBrightness(Context context) {
        int brightness = -1;
        ContentResolver resolver = context.getContentResolver();
        try {
            brightness = Settings.System.getInt(resolver, Settings.System.SCREEN_BRIGHTNESS);
        } catch (Settings.SettingNotFoundException e) {
            e.printStackTrace();
        }
        return brightness;
    }

    /**
     *获取系统最大屏幕亮度
     */
    public static int getMaxBrightness(Context context) {
        int brightnessSettingMaximumId = context.getResources().getIdentifier("config_screenBrightnessSettingMaximum", "integer", "android");
        int brightnessSettingMaximum = context.getResources().getInteger(brightnessSettingMaximumId);
        return brightnessSettingMaximum;
    }

    /**
     *调节当前屏幕亮度
     */
    public static void SetSystemLight(int lightnumber, Activity activity){
        Window window = activity.getWindow();//对当前窗口进行设置
        WindowManager.LayoutParams layoutparams = window.getAttributes();//获取窗口属性为后面亮度做铺垫作用
        layoutparams.screenBrightness =lightnumber / 255.0f;//用窗口管理（自定义的）layoutparams获取亮度值，android亮度值处于在0-255之间的整形数值
        window.setAttributes(layoutparams);//设置当前窗口屏幕亮度
    }

}

4、实现类（活动）

import android.os.Bundle;
import android.util.Log;
import android.widget.SeekBar;
import android.widget.TextView;

import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

    private static final String TAG ="MainActivity" ;
    private TextView textView;
    private SeekBar seekBar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_activity);
        initBrightness();

        /* 监听SeekBar */
        seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
            /*拖动条停止拖动时调用 */
            @Override
            public void onStopTrackingTouch(SeekBar seekBar) {
                Log.i(TAG, "拖动停止");
            }
            /*拖动条开始拖动时调用*/
            @Override
            public void onStartTrackingTouch(SeekBar seekBar) {
                Log.i(TAG, "开始拖动");
            }
            /* 拖动条进度改变时调用*/
            @Override
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                textView.setText("亮度值：" + progress);
                //当前屏幕亮度随着进度值改变
                BrightnessUtil.SetSystemLight(progress,MainActivity.this);
            }
        });
    }

    /* 初始化控件 */
    private void initBrightness(){
        textView = (TextView) findViewById(R.id.textView);
        seekBar = (SeekBar) findViewById(R.id.seekBar);

        textView.setText("亮度值：" + BrightnessUtil.getBrightness(MainActivity.this));
        //将系统最大屏幕亮度值设为seekbar的最大进度值
        seekBar.setMax(BrightnessUtil.getMaxBrightness(MainActivity.this));
        //将系统当前屏幕亮度值设为seekbar当前进度值
        seekBar.setProgress(BrightnessUtil.getBrightness(MainActivity.this));
    }

}

参考：https://blog.csdn.net/Jz_Panda/article/details/104441904
转载请注明出处～