Android自制精彩弹幕效果

好久没有写过文章,最近发现直播特别的火,很多app都集成了直播的功能,发现有些直播是带有弹幕的,效果还不错,今天心血来潮,特地写了篇制作弹幕的文章.

今天要实现的效果如下:

1.弹幕垂直方向固定

2.弹幕垂直方向随机

上面效果图中白色的背景就是弹幕本身,是一个自定义的framelayout,我这里是为了更好的展示弹幕的位置才设置成了白色,当然如果是叠加在videoview上的话,就需要设置成透明色了.
制作弹幕需要考虑以下几点问题:
1.弹幕的大小可以随意调整
2.弹幕内移动的item(或者称字幕)出现的位置,水平方向是从屏幕右边移动到屏幕左边,垂直方向是不能超出弹幕本身的高度的.
3.字幕移除屏幕后,需要将对应item(字幕)从其父容器(弹幕)中移除.
4.如果字幕出现的垂直方向的高度是随机的,那么还需要避免字幕重叠的情况.

ok,下面是弹幕自定义view的代码:

/**
 * created by dell on 2016/9/28.
 */
public class danmuview extends framelayout {
 private static final string tag = "danmuview";
 private static final long default_anim_duration = 6000; //默认每个动画的播放时长
 private static final long default_query_duration = 3000; //遍历弹幕的默认间隔
 private linkedlist<view> mviews = new linkedlist<>();//弹幕队列
 private boolean isquerying;
 private int mwidth;//弹幕的宽度
 private int mheight;//弹幕的高度
 private handler muihandler = new handler();
 private boolean topdirectionfixed;//弹幕顶部的方向是否固定
 private handler mqueryhandler;
 private int mtopgravity = gravity.center_vertical;//顶部方向固定时的默认对齐方式

 public void setheight(int height) {
  mheight = height;
 }

 public void setwidth(int width) {
  mwidth = width;
 }

 public void settopgravity(int gravity) {
  this.mtopgravity = gravity;
 }

 public void add(list<danmu> danmulist) {
  for (int i = 0; i < danmulist.size(); i++) {
   danmu danmu = danmulist.get(i);
   adddanmutoqueue(danmu);
  }
 }

 public void add(danmu danmu) {
  adddanmutoqueue(danmu);
 }

 public danmuview(context context) {
  this(context, null);
 }

 public danmuview(context context, attributeset attrs) {
  this(context, attrs, 0);
 }

 public danmuview(context context, attributeset attrs, int defstyleattr) {
  super(context, attrs, defstyleattr);
  handlerthread thread = new handlerthread("query");
  thread.start();
  //循环取出弹幕显示
  mqueryhandler = new handler(thread.getlooper()) {
   @override
   public void handlemessage(message msg) {
    final view view = mviews.poll();
    if (null != view) {
     muihandler.post(new runnable() {
      @override
      public void run() {
       //添加弹幕
       showdanmu(view);
      }
     });
    }
    sendemptymessagedelayed(0, default_query_duration);
   }
  };
 }

 /**
  * 将要展示的弹幕添加到队列中
  *
  * @param danmu
  */
 private void adddanmutoqueue(danmu danmu) {
  if (null != danmu) {
   final view view = view.inflate(getcontext(), r.layout.layout_danmu, null);
   textview usernametv = (textview) view.findviewbyid(r.id.tv_username);
   textview infotv = (textview) view.findviewbyid(r.id.tv_info);
   imageview headeriv = (imageview) view.findviewbyid(r.id.iv_header);
   usernametv.settext(danmu.getusername());//昵称
   infotv.settext(danmu.getinfo());//信息
   glide.with(getcontext()).//头像
     load(danmu.getheaderurl()).
     transform(new cropcircletransformation(getcontext())).into(headeriv);
   view.measure(0, 0);
   //添加弹幕到队列中
   mviews.offerlast(view);
  }
 }

 /**
  * 播放弹幕
  *
  * @param topdirectionfixed 弹幕顶部的方向是否固定
  */
 public void startplay(boolean topdirectionfixed) {
  this.topdirectionfixed = topdirectionfixed;
  if (mwidth == 0 || mheight == 0) {
   getviewtreeobserver().addongloballayoutlistener(new viewtreeobserver.ongloballayoutlistener() {
    @suppresslint("newapi")
    @override
    public void ongloballayout() {
     getviewtreeobserver().removeongloballayoutlistener(this);
     if (mwidth == 0) mwidth = getwidth() - getpaddingleft() - getpaddingright();
     if (mheight == 0) mheight = getheight() - getpaddingtop() - getpaddingbottom();
     if (!isquerying) {
      mqueryhandler.sendemptymessage(0);
     }
    }
   });
  } else {
   if (!isquerying) {
    mqueryhandler.sendemptymessage(0);
   }
  }
 }

 /**
  * 显示弹幕,包括动画的执行
  *
  * @param view
  */
 private void showdanmu(final view view) {
  isquerying = true;
  log.d(tag, "mwidth:" + mwidth + " mheight:" + mheight);
  final layoutparams lp = new layoutparams(view.getmeasuredwidth(), view.getmeasuredheight());
  lp.leftmargin = mwidth;
  if (topdirectionfixed) {
   lp.gravity = mtopgravity | gravity.left;
  } else {
   lp.gravity = gravity.left | gravity.top;
   lp.topmargin = getrandomtopmargin(view);
  }
  view.setlayoutparams(lp);
  view.settag(lp.topmargin);
  //设置item水平滚动的动画
  valueanimator animator = valueanimator.ofint(mwidth, -view.getmeasuredwidth());
  animator.addupdatelistener(new valueanimator.animatorupdatelistener() {
   @override
   public void onanimationupdate(valueanimator animation) {
    lp.leftmargin = (int) animation.getanimatedvalue();
    view.setlayoutparams(lp);
   }
  });
  addview(view);//显示弹幕
  animator.setduration(default_anim_duration);
  animator.setinterpolator(new linearinterpolator());
  animator.start();//开启动画
  animator.addlistener(new animatorlisteneradapter() {
   @override
   public void onanimationend(animator animation) {
    view.clearanimation();
    existmarginvalues.remove(view.gettag());//移除已使用过的顶部边距
    removeview(view);//移除弹幕
    animation.cancel();
   }
  });
 }

 //记录当前仍在显示状态的弹幕的垂直方向位置（避免重复）
 private set<integer> existmarginvalues = new hashset<>();
 private int linescount;
 private int range = 10;

 private int getrandomtopmargin(view view) {
  //计算可用的行数
  linescount = mheight / view.getmeasuredheight();
  if (linescount <= 1) {
   linescount = 1;
  }
  log.d(tag, "linescount:" + linescount);
  //检查重叠
  while (true) {
   int randomindex = (int) (math.random() * linescount);
   int marginvalue = randomindex * (mheight / linescount);
   //边界检查
   if (marginvalue > mheight - view.getmeasuredheight()) {
    marginvalue = mheight - view.getmeasuredheight() - range;
   }
   if (marginvalue == 0) {
    marginvalue = range;
   }
   if (!existmarginvalues.contains(marginvalue)) {
    existmarginvalues.add(marginvalue);
    log.d(tag, "marginvalue:" + marginvalue);
    return marginvalue;
   }
  }
 }
}

弹幕实体类:

/**
 * created by dell on 2016/9/28.
 */
public class danmu {
 private string headerurl;//头像
 private string username;//昵称
 private string info;//信息

 public string getheaderurl() {
  return headerurl;
 }

 public void setheaderurl(string headerurl) {
  this.headerurl = headerurl;
 }

 public string getusername() {
  return username;
 }

 public void setusername(string username) {
  this.username = username;
 }

 public string getinfo() {
  return info;
 }

 public void setinfo(string info) {
  this.info = info;
 }
}

测试类,mainactivity

public class mainactivity extends appcompatactivity {
 danmuview mdanmuview;
 edittext mmsgedt;
 button msendbtn;
 handler mdanmuaddhandler;
 boolean continueadd;
 int counter;

 @override
 protected void onresume() {
  super.onresume();
  mdanmuview.startplay(true);//true表示弹幕的垂直方向是固定的,false则随机
  continueadd = true;
  mdanmuaddhandler.sendemptymessagedelayed(0, 6000);
 }

 @override
 protected void onpause() {
  super.onpause();
  continueadd = false;
  mdanmuaddhandler.removemessages(0);
 }

 @override
 protected void oncreate(bundle savedinstancestate) {
  super.oncreate(savedinstancestate);
  setcontentview(r.layout.activity_main);
  initview();
  initdata();
  initlistener();
 }

 private void initview() {
  mdanmuview = (danmuview) findviewbyid(r.id.danmuview);
  mmsgedt = (edittext) findviewbyid(r.id.edt_msg);
  msendbtn = (button) findviewbyid(r.id.btn_send);
 }

 private void initdata() {
  list<danmu> danmulist = new arraylist<>();
  for (int i = 0; i < 3; i++) {
   danmu danmu = new danmu();
   danmu.setheaderurl("http://tupian.qqjay.com/tou3/2016/0725/cb00091099ffbf09f4861f2bbb5dd993.jpg");
   danmu.setusername("mr.chen" + i);
   danmu.setinfo("我是弹幕啊,不要问我为什么不可以那么长!!!");
   danmulist.add(danmu);
  }
  mdanmuview.add(danmulist);

  //下面是模拟每秒添加一个弹幕的过程
  handlerthread ht = new handlerthread("send danmu");
  ht.start();
  mdanmuaddhandler = new handler(ht.getlooper()) {
   @override
   public void handlemessage(message msg) {
    runonuithread(new runnable() {
     @override
     public void run() {
      danmu danmu = new danmu();
      danmu.setheaderurl("http://tupian.qqjay.com/tou3/2016/0803/87a8b262a5edeff0e11f5f0ba24fb22f.jpg");
      danmu.setusername("mr.new" + (counter++));
      danmu.setinfo("新的弹幕啊!!!新的弹幕啊!!!新的弹幕啊!!!新的弹幕啊!!!");
      mdanmuview.add(danmu);
     }
    });
    //继续添加
    if (continueadd) {
     sendemptymessagedelayed(0, 1000);
    }
   }
  };
 }

 private void initlistener() {
  //手动添加
  msendbtn.setonclicklistener(new view.onclicklistener() {
   @override
   public void onclick(view v) {
    string msg = mmsgedt.gettext().tostring().trim();
    if (textutils.isempty(msg)) {
     toast.maketext(mainactivity.this, "亲,你想发送什么啊?", toast.length_short).show();
     return;
    }
    mmsgedt.settext("");
    danmu danmu = new danmu();
    danmu.setheaderurl("http://img0.imgtn.bdimg.com/it/u=2198087564,4037394230&fm=11&gp=0.jpg");
    danmu.setusername("i'am good man");
    danmu.setinfo("我是新人:" + msg);
    mdanmuview.add(danmu);
   }
  });
 }
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。