Android实现自定义的弹幕效果

一、效果图

先来看看效果图吧~~

二、实现原理方案

1、自定义viewgroup-xcdanmuview，继承relativelayout来实现，当然也可以继承其他三大布局类哈

2、初始化若干个textview（弹幕的item view，这里以textview 为例，当然也可以其他了~），然后通过addview添加到自定义view中

3、通过addview添加到xcdanmuview中，位置在坐标，为了实现 从屏幕外移动进来的效果

我们还需要修改添加进来textview的位置，以从右向左移动方向来说，addview后必须将该textview的位置设置到右边的屏幕外

这样我们采用的方法，是在onlayout（）方法中对childview进行layout重新布局设置位置

4、随机冲左侧或右侧出来弹幕itemview，移动采用属性动画来实现平移，从屏幕的一端移动到另一端，当动画结束后，就将

该child从xcdanmuview中remove掉。并重新new 一个弹幕itemview ，并addview到xcdanmuview中，并开始动画移动

5、本自定义弹幕view支持从左到右和从右到左两个方向，支持自定义设置屏幕弹幕最多显示个数。

 

三、自定义弹幕效果xcdanmuview的具体实现

1、初始化需要用到的数据变量

private int mwidth;
  private int mscreenwidth;
  private list<view> mchildlist;
  private boolean misworking = false;
  private context mcontext;
  private int mmaxshownum = 15;
  private int mrownum = 4;
  private int[] mspeeds = {
      3000,4000,5000,6000
  };
  private int mdelayduration = 500;
  private int[] mbgresids = {
      r.drawable.bg_danmu0,
      r.drawable.bg_danmu1,
      r.drawable.bg_danmu2,
      r.drawable.bg_danmu3
  };
  private int[] mrowpos = {
      150,140,160,150
  };
  private random mrandom;
  private string[] mstrcontents;
  public static enum xcdirection{
    from_right_to_left,
    form_left_to_right
  }
  public enum xcaction{
    show,hide
  }
  private xcdirection mdirection = xcdirection.from_right_to_left;
　　private void init() {
  mscreenwidth = getscreenwidth();
  mchildlist = new arraylist<>();
  mrandom = new random();
}

2、初始化若干个弹幕item view

public void initdanmuitemviews(string[] strcontents){
    mstrcontents = strcontents;
    for(int i = 0; i < mmaxshownum; i ++){
      int index = mrandom.nextint(100) % strcontents.length;
      createdanmuview(i,strcontents[index],false);
    }
  }

3、创建弹幕item view 并addview到xcdanmuview中

public void createdanmuview(int index,string content,boolean reset){
    final textview textview = new textview(mcontext);
    textview.settextcolor(color.white);
    int r = mrandom.nextint(100) % mrownum;
    textview.setbackgroundresource(mbgresids[r]);
    textview.settext(content +"_"+ (index+1));
    relativelayout.layoutparams lp = new layoutparams(layoutparams.wrap_content,
        relativelayout.layoutparams.wrap_content);
    int row = mrandom.nextint(100) % mrownum;
    while(row == lastrow){
      row = mrandom.nextint(100)% mrownum;
    }
    int pos = mrandom.nextint(100)% mrownum;
    lp.topmargin = row * mrowpos[pos];
    lastrow = row;
    textview.setlayoutparams(lp);
    textview.setpadding(40, 2, 40, 2);
    this.addview(textview);
    if(reset){
      mchildlist.set(index,textview);
    }else{
      mchildlist.add(index,textview);
    }
    textview.setclickable(true);
    textview.setonclicklistener(new onclicklistener() {
      @override
      public void onclick(view view) {
        toast toast = toast.maketext(mcontext, textview.gettext(), toast.length_short);
        toast.setgravity(gravity.top,0,50);
        toast.show();
      }
    });
  }

4、重新设置childview的初始位置到屏幕之外

@override
  protected void onlayout(boolean changed, int l, int t, int r, int b) {
    super.onlayout(changed, l, t, r, b);
    int childcount = this.getchildcount();
    for(int i=0;i<childcount;i++){
      view view = getchildat(i);
      relativelayout.layoutparams lp = (layoutparams) view.getlayoutparams();
      if(lp.leftmargin <= 0){
        if(mdirection == xcdirection.form_left_to_right){
          view.layout(-view.getmeasuredwidth(), lp.topmargin,
              0,lp.topmargin + view.getmeasuredheight());
        }else{
          view.layout(mscreenwidth,lp.topmargin,mscreenwidth+view.getmeasuredwidth(),
              lp.topmargin+view.getmeasuredheight());
        }

      }else{
        continue;
      }
    }
  }

5、弹幕item view的移动效果

private handler mhandler = new handler() {
    @override
    public void handlemessage(final message msg) {
      super.handlemessage(msg);
      final int pos = msg.what;
      viewpropertyanimator animator;
      if(mdirection == xcdirection.from_right_to_left){
        animator = mchildlist.get(msg.what).animate()
            .translationxby(-(mscreenwidth + mchildlist.get(msg.what).getwidth()));
      }else{
        animator = mchildlist.get(msg.what).animate()
            .translationxby(mscreenwidth + mchildlist.get(msg.what).getwidth());
      }

      random random = new random(system.currenttimemillis());
      int index = random.nextint(100) % mspeeds.length;
      animator.setduration(mspeeds[index]);
      animator.setinterpolator(new linearinterpolator());
      animator.setlistener(new animator.animatorlistener() {
        @override
        public void onanimationstart(animator animator) {

        }

        @override
        public void onanimationend(animator animator) {
          xcdanmuview.this.removeview(mchildlist.get(pos));
          int index = mrandom.nextint(100) % mstrcontents.length;
          createdanmuview(pos, mstrcontents[index], true);
          mhandler.sendemptymessagedelayed(pos, mdelayduration);
          log.v("czm", "size=" + mchildlist.size());
        }

        @override
        public void onanimationcancel(animator animator) {

        }

        @override
        public void onanimationrepeat(animator animator) {

        }
      });
      animator.start();
    }
  };

 6、开启弹幕效果和关闭弹幕效果以及对于的动画效果

boolean isfirst = true;
  public void start(){
    switchanimation(xcaction.show);
    if(isfirst){
      for(int i =0;i< mchildlist.size();i++){
        mhandler.sendemptymessagedelayed(i,i * mdelayduration);
      }
      isfirst = false;
    }

    misworking = true;
  }
  public void hide(){
    switchanimation(xcaction.hide);
    misworking =false;
  }
  public void stop(){
    this.setvisibility(view.gone);
    for(int i =0;i< mchildlist.size();i++){
      mchildlist.get(i).clearanimation();
      mhandler.removemessages(i);
    }
    misworking =false;
  }
private void switchanimation(final xcaction action){
    alphaanimation animation;
    if(action == xcaction.hide){
      animation = new alphaanimation(1.0f,0.0f);
      animation.setduration(400);
    }else{
      animation = new alphaanimation(0.0f,1.0f);
      animation.setduration(1000);
    }
    xcdanmuview.this.startanimation(animation);
    animation.setanimationlistener(new animation.animationlistener() {
      @override
      public void onanimationstart(animation animation) {

      }
      @override
      public void onanimationend(animation animation) {
        if(action == xcaction.hide){
          xcdanmuview.this.setvisibility(view.gone);
        }else{
          xcdanmuview.this.setvisibility(view.visible);
        }
      }
      @override
      public void onanimationrepeat(animation animation) {

      }
    });
  }

四、如何使用该自定义侧滑view控件

使用该自定义view非常简单，控件默认效果从右向左，如果需要修改方向为从左到右，只需设置下方向即可

public class mainactivity extends activity {

  private xcdanmuview mdanmuview;
  private list<view> mviewlist;
  private string[] mstritems = {
      "搜狗","百度",
      "腾讯","360",
      "阿里巴巴","搜狐",
      "网易","新浪",
      "搜狗-上网从搜狗开始","百度一下,你就知道",
      "必应搜索-有求必应","好搜-用好搜，特顺手",
      "android-谷歌","ios-苹果",
      "windows-微软","linux"
  };
  @override
  protected void oncreate(bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.activity_main);
    initdanmuview();
    initlistener();
  }

  private void initlistener() {
    findviewbyid(r.id.btn).setonclicklistener(new view.onclicklistener() {
      @override
      public void onclick(view view) {
        if (mdanmuview.isworking()) {
          mdanmuview.hide();
          ((button) view).settext("开启弹幕");
        } else {
          mdanmuview.start();
          ((button) view).settext("关闭弹幕");
        }
      }
    });
  }

  private void initdanmuview() {
    mdanmuview = (xcdanmuview)findviewbyid(r.id.danmu);
    mdanmuview.initdanmuitemviews(mstritems);
  }

}

五、总结

以上就是在android中实现自定义弹幕效果的全部内容个，希望本文的内容对大家开发android的时候能有所帮助。如果有疑问可以留言交流。