Android开发之瀑布流控件的实现与使用方法示例

本文实例讲述了android开发之瀑布流控件的实现与使用方法。分享给大家供大家参考，具体如下：

public class flowlayout extends viewgroup {
  /**行里子view之间的行距离*/
  public int mhorizontolspace = util.getdimen(r.dimen.top_padding);
  /**行里子view之间的垂直距离*/
  public int mverticalspace = util.getdimen(r.dimen.top_padding);
  /**创建行的集合*/
  private list<line> mlines = new arraylist<line>();
  /**当前行*/
  private line mcurrentline;
  /**当前行使用的宽度*/
  private int mcurrentusewidth = 0;
  /**父容器的宽高*/
  private int parentwidthsize;
  private int parentheightsize;
  public flowlayout(context context, attributeset attrs, int defstyleattr) {
    super(context, attrs, defstyleattr);
  }
  public flowlayout(context context, attributeset attrs) {
    super(context, attrs);
  }
  public flowlayout(context context) {
    super(context);
  }
  @override
  protected void onmeasure(int widthmeasurespec, int heightmeasurespec) {
    //0.先清空行集合里的数据
    clear();
    //1.得到父viewgroup的模式与大小
    int parentwidthmode = measurespec.getmode(widthmeasurespec);//
    parentwidthsize = measurespec.getsize(widthmeasurespec) - getpaddingleft() - getpaddingright();
    int parentheightmode = measurespec.getmode(heightmeasurespec);
    parentheightsize = measurespec.getsize(heightmeasurespec) - getpaddingbottom() - getpaddingtop();
    /* 每个子view都是包裹内容
     * layout.addview(mtextview, new linearlayout.layoutparams(layoutparams.wrap_content
     * 得到每个孩子的测量规则
     */
    //2.得到每个孩子的模式
    int childwidthmode = parentwidthmode == measurespec.exactly ? measurespec.exactly : parentwidthmode;
    int childheightmode = parentheightmode == measurespec.exactly ? measurespec.exactly : parentheightmode;
    //3.根据模式得到子控件的大小
    int childwidthmeasurespec = measurespec.makemeasurespec(childwidthmode, parentwidthsize);
    int childheightmeasurespec = measurespec.makemeasurespec(childheightmode, parentheightsize);
    //得到子view的个数
    int count = getchildcount();
    //创建新的行
    mcurrentline = new line();
    for (int i = 0; i < count; i++) {
      view childview = getchildat(i);
      //4.测量每个孩子
      childview.measure(childwidthmeasurespec, childheightmeasurespec);
      //5.得到测量后的孩子的宽高
      int childmeasurewidth = measurespec.getsize(childwidthmeasurespec);
      //int childmeasureheight = measurespec.getsize(childheightmeasurespec);
      //6.得到此行使用的宽度
      mcurrentusewidth += childmeasurewidth;
      //7.判断此行的宽度是否大于父控件的宽度，如果大于则换行
      if (mcurrentusewidth > parentwidthsize) {
        //8.如果当前的子view的宽度大于父容器的宽度，强行把这个view添加的集合里
        if (mcurrentline.getchildcount()<1) {
          mlines.add(mcurrentline); 
        }
        //9.换行
        newline();
      }else {
        //8.把当前子view添加到行里
        mcurrentline.addchild(childview);
        //9.添加间隔
        mcurrentusewidth += mhorizontolspace;
        if (mcurrentusewidth > parentwidthsize) {
          //10.换行
          newline();
        }
      }
    }
    //11.如果集合里没有添加当前行，则把当前添加到集合
    if (!mlines.contains(mcurrentline)) {
      mlines.add(mcurrentline);
    }
    //12.设置富容器的总宽高
    int parentwidth = parentwidthsize + getpaddingleft() + getpaddingright();
    int parentheight = (mlines.size()-1) * mverticalspace + getpaddingbottom() + getpaddingtop();
    for(line line : mlines){
      //得到所以line的高度
      parentheight += line.getheight();
    }
    //13.resolvesize表示哪个高度合适，就用哪个
    setmeasureddimension(parentwidth, resolvesize(parentheightsize, parentheight));
    /*setmeasureddimension(getdefaultsize(getsuggestedminimumwidth(), widthmeasurespec),
        getdefaultsize(getsuggestedminimumheight(), heightmeasurespec));*/
  }
  /**
   * 换行
   */
  private void newline() {
    //a.先把当前的行添加到集合
    mlines.add(mcurrentline);
    //b.创建新的一行
    mcurrentline = new line();
    //c.新行里的使用的行必须设置为0
    mcurrentusewidth = 0;
  }
  public void clear() {
    mlines.clear();
    mcurrentline = null;
    mcurrentusewidth = 0;
  }
  @override
  protected void onlayout(boolean changed, int l, int t, int r, int b) {
    //15.得到每个line孩子的左上角的坐标
    int left = l + getpaddingleft();
    int top = t + getpaddingtop();
    //现在容器里只有line是子孩子
    for (int i = 0; i < mlines.size(); i++) {
      line line = mlines.get(i);
      //16.把分配位置给line去处理
      line.layout(left, top);
      //17.设置第一行后的其它行的top数值
      top += line.getheight() + mverticalspace;
    }
  }
  /**
   * 行类，用来封装一行的view
   */
  private class line{
    /**当前行的宽度*/
    private int mwidth = 0;
    /**当前行的高度*/
    private int mheight = 0;
    /**每个孩子得到的剩余空间*/
    int mchildpdding = 0;
    private list<view> children = new arraylist<view>();
    public void addchild(view childview) {
      children.add(childview);
      //取得之view里最高的高度
      if (childview.getmeasuredheight() > mheight) {
        mheight = childview.getmeasuredheight();
      }
      //18.得到行宽度
      mwidth += childview.getmeasuredwidth();
    }
    /**
     * 定位每个line在富容器里的额位置
     * @param left
     * @param top
     */
    public void layout(int left, int top) {
      //18.得到行宽度
      mwidth += mhorizontolspace * (children.size() -1);
      //19.得到剩余的宽度大小
      //int padding = getmeasuredwidth() - mwidth;
      int padding = parentwidthsize - mwidth;
      if (padding > 0) {
        mchildpdding = padding / children.size();
      }
      // getwidth()view显示的时候大小,如果view没显示,这个值就为0,步包括隐藏的部分, getmeasuredwidth()控件实际大小,包括隐藏的部分
      //一般来说 getmeasuredwidth() > getwidth();
      for (int i = 0; i < children.size(); i++) {
        view child = children.get(i);
        //第一种：有间隔的flow
        int bottom = child.getmeasuredheight() + top;
        //20.把剩余的空间分配给每个view
        int right = child.getmeasuredwidth() + left + mchildpdding;
        //第二种：无间隔的flow
//       int bottom = getmeasuredheight() + top;
//       int right = getmeasuredwidth() + left;
        //第一个child的位置
        child.layout(left, top, right, bottom);
        //第二个及后面child的right
        right += child.getmeasuredwidth() + mhorizontolspace + mchildpdding;
      }
    }
    /**
     * 得到子view的大小
     * @return
     */
    public int getchildcount() {
      if (children != null) {
        return children.size();
      }
      return 0;
    }
    public int getheight() {
      return mheight;
    }
  }
}

使用方法：

public class topfragment extends fragment{
  @override
  public view oncreateview(layoutinflater inflater, viewgroup container, bundle savedinstancestate) {
    scrollview scrollview = new scrollview(getactivity());
    flowlayout layout = new flowlayout(getactivity());
    layout.setbackgrounddrawable(util.getdrawable(r.drawable.list_item_bg));
    int padding = util.getdimen(r.dimen.top_padding);
    layout.setpadding(padding, padding, padding, padding);
    gradientdrawable pressdrawable = drawableutil.createdrawable(0xffcecece);
    for (int i = 0; i < mdatas.size(); i++) {
      mtextview = new textview(getactivity());
      mtextview.settext(mdatas.get(i));
      gradientdrawable randomdrawable = drawableutil.createrandomdrawable();
      statelistdrawable statelistdrawable = drawableutil.createstatedrawable(pressdrawable, randomdrawable);
      mtextview.setbackgrounddrawable(statelistdrawable);
      mtextview.settextcolor(color.white);
      int left = util.px2dip(7);
      int top = util.px2dip(4);
      int right = util.px2dip(7);
      int bottom = util.px2dip(4);
      mtextview.setpadding(left, top, right, bottom);
      mtextview.settag(mdatas.get(i));
      mtextview.setonclicklistener(this);
      layout.addview(mtextview, new linearlayout.layoutparams(layoutparams.wrap_content, - 2));
    }
    scrollview.addview(layout);
    }
    return scrollview;
}

工具类:

public class drawableutil {
  /**
   * 创建随机背景的drawable
   * @return
   */
  public static gradientdrawable createrandomdrawable(){
    gradientdrawable drawable = new gradientdrawable();
    drawable.setcornerradius(util.px2dip(5));
    random random = new random();
    int red = random.nextint(200) + 20;
    int green = random.nextint(200) + 20;
    int blue = random.nextint(200) + 20;
    int color = color.rgb(red, green, blue);
    drawable.setcolor(color);
    return drawable;
  }
    /**
     * 创建带有背景的drawable
     * @return
     */
    public static gradientdrawable createdrawable(int color){
      gradientdrawable drawable = new gradientdrawable();
      drawable.setcornerradius(util.px2dip(5));
      drawable.setcolor(color);
      return drawable;
  }
  /**
   * 状态选择器
   * @param press
   * @param normal
   * @return
   */
  public static statelistdrawable createstatedrawable(drawable press, drawable normal){
    statelistdrawable drawable = new statelistdrawable();
    //按下
    drawable.addstate(new int[]{android.r.attr.state_pressed}, press);
    //正常
    drawable.addstate(new int[]{}, normal);
    return drawable;
  }
}

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希望本文所述对大家android程序设计有所帮助。