一.背景

做視頻用到了就記錄下，從github(https://github.com/curtis2/SuperVideoPlayer 謝謝)上扒了一個項目的手勢調亮度和音量（但是有bug！！！就是調節音量感覺會突然消失）,本文重點是如何調節音量

二.代碼

package com.example.administrator.gesturetext;

import android.content.Context;
import android.media.AudioManager;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.view.Display;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.WindowManager;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.RelativeLayout;

public class MainActivity extends AppCompatActivity {

    private FrameLayout mVolumeBrightnessLayout;
    private ImageView mOperationBg;
    private ImageView mOperationPercent;
    private GestureDetector mGestureDetector;
    private AudioManager mAudioManager;
    private int mMaxVolume;
    private int mVolume = -1;
    private float mBrightness = -1f;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        RelativeLayout rlContentContainer = (RelativeLayout) findViewById(R.id.rl_content_container);
        mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
        mMaxVolume = mAudioManager.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
        mVolumeBrightnessLayout = (FrameLayout) findViewById(R.id.operation_volume_brightness);
        mOperationBg = (ImageView) findViewById(R.id.operation_bg);
        mOperationPercent = (ImageView) findViewById(R.id.operation_percent);
        mGestureDetector = new GestureDetector(MainActivity.this, new VolumeBrightnesGestureListener());
        rlContentContainer.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent motionEvent) {
                if (mGestureDetector.onTouchEvent(motionEvent)) {
                    return true;
                }
                switch (motionEvent.getAction() & MotionEvent.ACTION_MASK) {
                    case MotionEvent.ACTION_DOWN:
                        break;
                    case MotionEvent.ACTION_UP:
                        endGesture();
                        break;
                }
                return true;
            }
        });
    }


    private Handler mDismissHandler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            if (msg.what == 0) {
                mVolumeBrightnessLayout.setVisibility(View.GONE);
            }
        }
    };
    private void endGesture() {
        mVolume = -1;
        mBrightness = -1f;
        // 隱藏
        mDismissHandler.removeMessages(0);
        mDismissHandler.sendEmptyMessageDelayed(0, 500);
    }
    private class VolumeBrightnesGestureListener extends GestureDetector.SimpleOnGestureListener {
        @Override
        public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
            float mOldX = e1.getX(), mOldY = e1.getY();
            int y = (int) e2.getRawY();
            Display disp = getWindowManager().getDefaultDisplay();
            int windowWidth = disp.getWidth();
            int windowHeight = disp.getHeight();
            //1440 2392
            if (mOldX > windowWidth * 3.0 / 5) {
                onVolumeSlide((mOldY - y) / windowHeight);
                return true;
            } else if (mOldX < windowWidth *2.0/ 5.0) {
                onBrightnessSlide((mOldY - y) / windowHeight);
                return true;
            }
            return false;
        }
    }

    /**
     * 聲音高低
     *
     * @param percent
     */
    private void onVolumeSlide(float percent) {
        if (mVolume == -1) {
            mVolume = mAudioManager.getStreamVolume(AudioManager.STREAM_MUSIC);
            if (mVolume < 0)
                mVolume = 0;

            mOperationBg.setImageResource(R.drawable.video_volumn_bg);
            mVolumeBrightnessLayout.setVisibility(View.VISIBLE);
        }
        int index = (int) (percent * mMaxVolume) + mVolume;
        if (index > mMaxVolume)
            index = mMaxVolume;
        else if (index < 0)
            index = 0;

        mAudioManager.setStreamVolume(AudioManager.STREAM_MUSIC, index, 0);
        ViewGroup.LayoutParams lp = mOperationPercent.getLayoutParams();
        lp.width = findViewById(R.id.operation_full).getLayoutParams().width * index / mMaxVolume;
        mOperationPercent.setLayoutParams(lp);
    }


    /**
     * 處理屏幕亮暗
     *
     * @param percent
     */
    private void onBrightnessSlide(float percent) {
        if (mBrightness < 0) {
            mBrightness = getWindow().getAttributes().screenBrightness;
            if (mBrightness <= 0.00f)
                mBrightness = 0.50f;
            if (mBrightness < 0.01f)
                mBrightness = 0.01f;

            mOperationBg.setImageResource(R.drawable.video_brightness_bg);
            mVolumeBrightnessLayout.setVisibility(View.VISIBLE);
        }
        WindowManager.LayoutParams lpa = getWindow().getAttributes();
        lpa.screenBrightness = mBrightness + percent;
        if (lpa.screenBrightness > 1.0f)
            lpa.screenBrightness = 1.0f;
        else if (lpa.screenBrightness < 0.01f)
            lpa.screenBrightness = 0.01f;
        getWindow().setAttributes(lpa);

        ViewGroup.LayoutParams lp = mOperationPercent.getLayoutParams();
        lp.width = (int) (findViewById(R.id.operation_full).getLayoutParams().width * lpa.screenBrightness);
        mOperationPercent.setLayoutParams(lp);
    }
}

 

 

三.代碼分析

（1）屏幕亮暗度

 

WindowManager.LayoutParams lpa = getWindow().getAttributes();
lpa.screenBrightness = mBrightness + percent;
if (lpa.screenBrightness > 1.0f)
    lpa.screenBrightness = 1.0f;
else if (lpa.screenBrightness < 0.01f)
    lpa.screenBrightness = 0.01f;
getWindow().setAttributes(lpa);

注意！！！：如果要跟系統同步 需要寫WRITTING_SETTING權限,Android6.0及以上需要寫個intent手動設置，在清單文件中寫沒用的（這個太傻比了，估計沒人會要這麼做）

(2)音量

我們這裡只設置了媒體音樂

mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE)
mAudioManager.getStreamVolume(AudioManager.STREAM_MUSIC);

mAudioManager.setStreamVolume(AudioManager.STREAM_MUSIC, index, 0);

音量分很多種

public static final int STREAM_ALARM = 4;
public static final int STREAM_DTMF = 8;
public static final int STREAM_MUSIC = 3;
public static final int STREAM_NOTIFICATION = 5;
public static final int STREAM_RING = 2;
public static final int STREAM_SYSTEM = 1

可以看出有很多種，套路都是一樣的

代碼鏈接待添加