Android视频播放器屏幕左侧边随手指上下滑动亮度调节功能的原理实现

本文给大家分享Android视频播放器屏幕左侧边随手指上下滑动亮度调节功能的原理实现，具体代码如下所示：

import android.app.Activity;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.WindowManager;
import android.widget.TextView;
public class MainActivity extends Activity {
  private float startY = 0;//手指按下时的Y坐标
  private float startX = 0;//手指按下时的Y坐标
  private TextView brightnessTextView;
  private View mVideoView;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    mVideoView = LayoutInflater.from(this).inflate(R.layout.activity_main, null);
    setContentView(mVideoView);
    brightnessTextView = (TextView) mVideoView.findViewById(R.id.text);
  }
  /*
  * 设置屏幕亮度
  * 0 最暗
  * 1 最亮
  */
  public void setBrightness(float brightness) {
    WindowManager.LayoutParams lp = getWindow().getAttributes();
    lp.screenBrightness = lp.screenBrightness + brightness / 255.0f;
    if (lp.screenBrightness > 1) {
      lp.screenBrightness = 1;
    } else if (lp.screenBrightness < 0.1) {
      lp.screenBrightness = (float) 0.1;
    }
    getWindow().setAttributes(lp);
    float sb = lp.screenBrightness;
    brightnessTextView.setText((int) Math.ceil(sb * 100) + "%");
  }
  @Override
  public boolean onTouchEvent(MotionEvent event) {
    int screenWidth = mVideoView.getWidth();
    switch (event.getAction()) {
      case MotionEvent.ACTION_DOWN:
        startX = event.getX();
        startY = event.getY();
        break;
      case MotionEvent.ACTION_MOVE:
        float endY = event.getY();
        float distanceY = startY - endY;
        if (startX > screenWidth / 2) {
          //右边
          //在这里处理音量
        } else {
          //屏幕左半部分上滑，亮度变大，下滑，亮度变小
          final double FLING_MIN_DISTANCE = 0.5;
          final double FLING_MIN_VELOCITY = 0.5;
          if (distanceY > FLING_MIN_DISTANCE && Math.abs(distanceY) > FLING_MIN_VELOCITY) {
            setBrightness(10);
          }
          if (distanceY < FLING_MIN_DISTANCE && Math.abs(distanceY) > FLING_MIN_VELOCITY) {
            setBrightness(-10);
          }
        }
        break;
    }
    return super.onTouchEvent(event);
  }
}  

activity_main.xml布局文件：

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:id="@+id/activity_main"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:background="@mipmap/ic_launcher">  

  <TextView
    android:id="@+id/text"
    android:layout_width="150dp"
    android:layout_height="50dp"
    android:layout_gravity="center"
    android:background="@android:color/holo_orange_light"
    android:gravity="center"
    android:textColor="@android:color/white" />
</FrameLayout> 

以上所述是小编给大家介绍的Android视频播放器屏幕左侧边随手指上下滑动亮度调节功能的原理实现，希望对大家有所帮助，如果大家有任何疑问请给我留言，小编会及时回复大家的。在此也非常感谢大家对我们网站的支持！