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