ปรับความสว่าง screen brightness #Android

by Unknown 00:38 0 ความคิดเห็น ANDROID

วันนี้เป็นบทความ screen brightness ปกติเวลาจะปรับค่าความสว่างของหน้าจอ Android จะต้องทำผ่านการตั้งค่า แต่คราวนี้ จะมาลองเขียน Application เพื่อปรับค่าความสว่างของหน้าจอเองซะเลย

ก่อนอื่นเลยต้อง Create project ขึ้นมาก่อน 

activity_main.xml

<RelativeLayout 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"
    tools:context="${relativePackage}.${activityClass}" >

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="109dp"
        android:layout_marginTop="50dp"
        android:text="Brightness Screen" />

    <SeekBar
        android:id="@+id/seekBar1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_below="@+id/textView1"
        android:layout_marginTop="100dp" />

    <TextView
        android:id="@+id/textView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBottom="@+id/seekBar1"
        android:layout_alignLeft="@+id/textView1"
        android:layout_marginBottom="48dp"
        android:text="Large Text"
        android:textAppearance="?android:attr/textAppearanceLarge" />

MainActivity.java

package com.NUrobot.brightnessscreen;

import android.app.Activity;
import android.content.ContentResolver;
import android.os.Bundle;
import android.provider.Settings.SettingNotFoundException;
import android.provider.Settings.System;
import android.util.Log;
import android.view.Window;
import android.view.WindowManager.LayoutParams;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;
import android.widget.TextView;


public class MainActivity extends Activity {
 
 private SeekBar brightbar;
  
    //Variable to store brightness value
    private int brightness;
    //Content resolver used as a handle to the system's settings
    private ContentResolver cResolver;
    //Window object, that will store a reference to the current window
    private Window window;
 
    private TextView txtPerc;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  
  brightbar = (SeekBar) findViewById(R.id.seekBar1);
   
        txtPerc = (TextView) findViewById(R.id.textView2);
 
        //Get the content resolver
        cResolver = getContentResolver();
 
        //Get the current window
        window = getWindow();
 
        //Set the seekbar range between 0 and 255
        brightbar.setMax(255);
        //Set the seek bar progress to 1
        brightbar.setKeyProgressIncrement(1);try
        {
            //Get the current system brightness
            brightness = System.getInt(cResolver,System.SCREEN_BRIGHTNESS);
        } 
        catch (SettingNotFoundException e) 
        {
            //Throw an error case it couldn't be retrieved
            Log.e("Error", "Cannot access system brightness");
            e.printStackTrace();
        }
 
        //Set the progress of the seek bar based on the system's brightness
        brightbar.setProgress(brightness);
 
        //Register OnSeekBarChangeListener, so it can actually change values
        brightbar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() 
        {
            public void onStopTrackingTouch(SeekBar seekBar) 
            {
                //Set the system brightness using the brightness variable value
                System.putInt(cResolver, System.SCREEN_BRIGHTNESS, brightness);
                //Get the current window attributes
                LayoutParams layoutpars = window.getAttributes();
                //Set the brightness of this window
                layoutpars.screenBrightness = brightness / (float)255;
                //Apply attribute changes to this window
                window.setAttributes(layoutpars);
            }
 
            public void onStartTrackingTouch(SeekBar seekBar) 
            {
                //Nothing handled here
            }
 
            public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) 
            {
                //Set the minimal brightness level
                //if seek bar is 20 or any value below
                if(progress<=20)
                {
                    //Set the brightness to 20
                    brightness=20;
                }
                else //brightness is greater than 20
                {
                    //Set brightness variable based on the progress bar 
                    brightness = progress;
                }
                //Calculate the brightness percentage
                float perc = (brightness /(float)255)*100;
                //Set the brightness percentage 
                txtPerc.setText((int)perc +" %");
            }
        });    
    }}
 

AndroidMannifest.xml เพิ่ม permission 

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

คลิกขวา >> project >> Run as >> Android application

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