Android自定义ViewGroup实现标签浮动效果

/** * 流式标签(动态的，根据传入的数据动态添加标签) */public class DynamicTagFlowLayout extends ViewGroup {  private List<String> mTags = new ArrayList<String>();  public DynamicTagFlowLayout(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); } public DynamicTagFlowLayout(Context context, AttributeSet attrs) { super(context, attrs); } public DynamicTagFlowLayout(Context context) { super(context); }  @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { int widthMode = MeasureSpec.getMode(widthMeasureSpec); int widthSize = MeasureSpec.getSize(widthMeasureSpec); int heightMode = MeasureSpec.getMode(heightMeasureSpec); int heightSize = MeasureSpec.getSize(heightMeasureSpec);  //当前ViewGroup的总高度 int totalHeight= 0; //所有行中的最大宽度 int maxLineWidth = 0;  //当前行的最大高度 int lineMaxHeight = 0; //当前行的总宽度 int currentLineWidth = 0;  //每个childView所占用的宽度 int childViewWidthSpace = 0; //每个childView所占用的高度 int childViewHeightSpace = 0;  int count = getChildCount(); MarginLayoutParams layoutParams;  for(int i = 0; i < count; i++){  View child = getChildAt(i);    if(child.getVisibility() != View.GONE){//只有当这个View能够显示的时候才去测量  //测量每个子View，以获取子View的宽和高  measureChild(child, widthMeasureSpec, heightMeasureSpec);    layoutParams = (MarginLayoutParams) child.getLayoutParams();    childViewWidthSpace = child.getMeasuredWidth() + layoutParams.leftMargin + layoutParams.rightMargin;  childViewHeightSpace = child.getMeasuredHeight() + layoutParams.topMargin + layoutParams.bottomMargin;    if(currentLineWidth + childViewWidthSpace > widthSize){//表示如果当前行再加上现在这个子View，就会超出总的规定宽度，需要另起一行   totalHeight += lineMaxHeight;   if(maxLineWidth < currentLineWidth){//如果行的最长宽度发生了变化，更新保存的最长宽度   maxLineWidth = currentLineWidth;   }   currentLineWidth = childViewWidthSpace;//另起一行后，需要重置当前行宽   lineMaxHeight = childViewHeightSpace;  }else{//表示当前行可以继续添加子元素   currentLineWidth += childViewWidthSpace;   if(lineMaxHeight < childViewHeightSpace){   lineMaxHeight = childViewHeightSpace;   }  }  } }  setMeasuredDimension(widthMode == MeasureSpec.EXACTLY ? widthSize : maxLineWidth, heightMode == MeasureSpec.EXACTLY ? heightSize : totalHeight);  } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { //当前是第几行 int currentLine = 1; //存放每一行的最大高度 List<Integer> lineMaxHeightList = new ArrayList<Integer>();  //每个childView所占用的宽度 int childViewWidthSpace = 0; //每个childView所占用的高度 int childViewHeightSpace = 0;  //当前行的最大高度 int lineMaxHeight = 0; //当前行的总宽度 int currentLineWidth = 0;  int count = getChildCount(); MarginLayoutParams layoutParams;  for(int i = 0; i < count; i++){  int cl= 0, ct = 0, cr = 0, cb = 0;  View child = getChildAt(i);  if(child.getVisibility() != View.GONE){//只有当这个View能够显示的时候才去测量    layoutParams = (MarginLayoutParams) child.getLayoutParams();  childViewWidthSpace = child.getMeasuredWidth() + layoutParams.leftMargin + layoutParams.rightMargin;  childViewHeightSpace = child.getMeasuredHeight() + layoutParams.topMargin + layoutParams.bottomMargin;    System.out.println("getWidth()---->"+getWidth());    if(currentLineWidth + childViewWidthSpace > getWidth()){//表示如果当前行再加上现在这个子View，就会超出总的规定宽度，需要另起一行   lineMaxHeightList.add(lineMaxHeight);//此时先将这一行的最大高度加入到集合中   //新的一行，重置一些参数   currentLine++;   currentLineWidth = childViewWidthSpace;   lineMaxHeight = childViewHeightSpace;      cl = layoutParams.leftMargin;   if(currentLine > 1){   for(int j = 0; j < currentLine - 1; j++){    ct += lineMaxHeightList.get(j);   }   ct += layoutParams.topMargin ;   }else{   ct = layoutParams.topMargin;   }  }else{//表示当前行可以继续添加子元素   cl = currentLineWidth + layoutParams.leftMargin;   if(currentLine > 1){   for(int j = 0; j < currentLine - 1; j++){    ct += lineMaxHeightList.get(j);   }   ct += layoutParams.topMargin;   }else{   ct = layoutParams.topMargin;   }   currentLineWidth += childViewWidthSpace;   if(lineMaxHeight < childViewHeightSpace){   lineMaxHeight = childViewHeightSpace;   }  }    cr = cl + child.getMeasuredWidth();  cb = ct + child.getMeasuredHeight();    child.layout(cl, ct, cr, cb);    } } }  @Override public LayoutParams generateLayoutParams(AttributeSet attrs) { return new MarginLayoutParams(getContext(), attrs); }  public void setTags(List<String> tags){ if(tags!= null){  mTags.clear();  mTags.addAll(tags);  for(int i = 0; i < mTags.size(); i++){  TextView tv = new TextView(getContext());  MarginLayoutParams lp = new MarginLayoutParams(MarginLayoutParams.WRAP_CONTENT, MarginLayoutParams.WRAP_CONTENT);  lp.setMargins(15, 15, 15, 15);//  lp.width = MarginLayoutParams.WRAP_CONTENT;//  lp.height = MarginLayoutParams.WRAP_CONTENT;  tv.setLayoutParams(lp);  tv.setBackgroundResource(R.drawable.tv_bg);  /*   * setPadding一定要在setBackgroundResource后面使用才有效！！！   * http://stackoverflow.com/questions/18327498/setting-padding-for-textview-not-working   */  tv.setPadding(15, 15, 15, 15);  tv.setTextColor(Color.WHITE);    tv.setText(mTags.get(i));    tv.setOnClickListener(new OnClickListener() {   @Override   public void onClick(View v) {   if(listener != null){    listener.onClick(v);   }   }  });    addView(tv);  }  requestLayout(); } }  private OnTagItemClickListener listener; public interface OnTagItemClickListener{ public void onClick(View v); } public void setOnTagItemClickListener(OnTagItemClickListener l){ listener = l; }}

public class MainActivity extends Activity {  private DynamicTagFlowLayout dynamicTagFlowLayout;  List<String> tags = new ArrayList<String>(); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_dynamic_tagflowlayout);  dynamicTagFlowLayout = (DynamicTagFlowLayout) findViewById(R.id.dynamic_tag); dynamicTagFlowLayout.setOnTagItemClickListener(new OnTagItemClickListener() {  @Override  public void onClick(View v) {  TextView tv = (TextView) v;  Toast.makeText(MainActivity.this, tv.getText().toString(), Toast.LENGTH_SHORT).show();  } });  initData(); dynamicTagFlowLayout.setTags(tags); } private void initData() { tags.add("阳哥你好！"); tags.add("Android开发"); tags.add("新闻热点"); tags.add("热水进宿舍啦！"); tags.add("I love you"); tags.add("成都妹子"); tags.add("新余妹子"); tags.add("仙女湖"); tags.add("创新工厂"); tags.add("孵化园"); tags.add("神州100发射"); tags.add("有毒疫苗"); tags.add("顶你阳哥阳哥"); tags.add("Hello World"); tags.add("闲逛的蚂蚁"); tags.add("闲逛的蚂蚁"); tags.add("闲逛的蚂蚁"); tags.add("闲逛的蚂蚁"); tags.add("闲逛的蚂蚁"); tags.add("闲逛的蚂蚁"); }}