热门标签流式布局的实现--防网易云音乐热门标签

详情请看大神http://blog.csdn.net/jdsjlzx/article/details/45042081?ref=myread

热门标签流式布局的实现

1. 自定义热门标签的ViewGroup实现

   　　根据上面的技术分析，自定义类继承于ViewGroup，并重写 onMeasure和onLayout等方法。具体实现代码如下：

    package com.czm.flowlayout;  

    import java.util.ArrayList;  
    import java.util.List;  

    import android.content.Context;  
    import android.util.AttributeSet;  
    import android.view.View;  
    import android.view.ViewGroup;  
    /** * * @author caizhiming * @created on 2015-4-13 */  
    public class XCFlowLayout extends ViewGroup{  

        //存储所有子View 
        private List<List<View>> mAllChildViews = new ArrayList<>();  
        //每一行的高度 
        private List<Integer> mLineHeight = new ArrayList<>();  

        public XCFlowLayout(Context context) {  
            this(context, null);  
            // TODO Auto-generated constructor stub 
        }  
        public XCFlowLayout(Context context, AttributeSet attrs) {  
            this(context, attrs, 0);  
            // TODO Auto-generated constructor stub 
        }  
        public XCFlowLayout(Context context, AttributeSet attrs, int defStyle) {  
            super(context, attrs, defStyle);  
            // TODO Auto-generated constructor stub 
        }  
        @Override  
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {  
            // TODO Auto-generated method stub 

            //父控件传进来的宽度和高度以及对应的测量模式 
            int sizeWidth = MeasureSpec.getSize(widthMeasureSpec);  
            int modeWidth = MeasureSpec.getMode(widthMeasureSpec);  
            int sizeHeight = MeasureSpec.getSize(heightMeasureSpec);  
            int modeHeight = MeasureSpec.getMode(heightMeasureSpec);  

            //如果当前ViewGroup的宽高为wrap_content的情况 
            int width = 0;//自己测量的 宽度 
            int height = 0;//自己测量的高度 
            //记录每一行的宽度和高度 
            int lineWidth = 0;  
            int lineHeight = 0;  

            //获取子view的个数 
            int childCount = getChildCount();  
            for(int i = 0;i < childCount; i ++){  
                View child = getChildAt(i);  
                //测量子View的宽和高 
                measureChild(child, widthMeasureSpec, heightMeasureSpec);  
                //得到LayoutParams 
                MarginLayoutParams lp = (MarginLayoutParams) getLayoutParams();  
                //子View占据的宽度 
                int childWidth = child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin;  
                //子View占据的高度 
                int childHeight = child.getMeasuredHeight() + lp.topMargin + lp.bottomMargin;  
                //换行时候 
                if(lineWidth + childWidth > sizeWidth){  
                    //对比得到最大的宽度 
                    width = Math.max(width, lineWidth);  
                    //重置lineWidth 
                    lineWidth = childWidth;  
                    //记录行高 
                    height += lineHeight;  
                    lineHeight = childHeight;  
                }else{//不换行情况 
                    //叠加行宽 
                    lineWidth += childWidth;  
                    //得到最大行高 
                    lineHeight = Math.max(lineHeight, childHeight);  
                }  
                //处理最后一个子View的情况 
                if(i == childCount -1){  
                    width = Math.max(width, lineWidth);  
                    height += lineHeight;  
                }  
            }  
            //wrap_content 
            setMeasuredDimension(modeWidth == MeasureSpec.EXACTLY ? sizeWidth : width,  
                    modeHeight == MeasureSpec.EXACTLY ? sizeHeight : height);  
            super.onMeasure(widthMeasureSpec, heightMeasureSpec);  
        }  

        @Override  
        protected void onLayout(boolean changed, int l, int t, int r, int b) {  
            // TODO Auto-generated method stub 
            mAllChildViews.clear();  
            mLineHeight.clear();  
            //获取当前ViewGroup的宽度 
            int width = getWidth();  

            int lineWidth = 0;  
            int lineHeight = 0;  
            //记录当前行的view 
            List<View> lineViews = new ArrayList<View>();  
            int childCount = getChildCount();  
            for(int i = 0;i < childCount; i ++){  
                View child = getChildAt(i);  
                MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();  
                int childWidth = child.getMeasuredWidth();  
                int childHeight = child.getMeasuredHeight();  

                //如果需要换行 
                if(childWidth + lineWidth + lp.leftMargin + lp.rightMargin > width){  
                    //记录LineHeight 
                    mLineHeight.add(lineHeight);  
                    //记录当前行的Views 
                    mAllChildViews.add(lineViews);  
                    //重置行的宽高 
                    lineWidth = 0;  
                    lineHeight = childHeight + lp.topMargin + lp.bottomMargin;  
                    //重置view的集合 
                    lineViews = new ArrayList();  
                }  
                lineWidth += childWidth + lp.leftMargin + lp.rightMargin;  
                lineHeight = Math.max(lineHeight, childHeight + lp.topMargin + lp.bottomMargin);  
                lineViews.add(child);  
            }  
            //处理最后一行 
            mLineHeight.add(lineHeight);  
            mAllChildViews.add(lineViews);  

            //设置子View的位置 
            int left = 0;  
            int top = 0;  
            //获取行数 
            int lineCount = mAllChildViews.size();  
            for(int i = 0; i < lineCount; i ++){  
                //当前行的views和高度 
                lineViews = mAllChildViews.get(i);  
                lineHeight = mLineHeight.get(i);  
                for(int j = 0; j < lineViews.size(); j ++){  
                    View child = lineViews.get(j);  
                    //判断是否显示 
                    if(child.getVisibility() == View.GONE){  
                        continue;  
                    }  
                    MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();  
                    int cLeft = left + lp.leftMargin;  
                    int cTop = top + lp.topMargin;  
                    int cRight = cLeft + child.getMeasuredWidth();  
                    int cBottom = cTop + child.getMeasuredHeight();  
                    //进行子View进行布局 
                    child.layout(cLeft, cTop, cRight, cBottom);  
                    left += child.getMeasuredWidth() + lp.leftMargin + lp.rightMargin;  
                }  
                left = 0;  
                top += lineHeight;  
            }  

        }  
        /** * 与当前ViewGroup对应的LayoutParams */  
        @Override  
        public LayoutParams generateLayoutParams(AttributeSet attrs) {  
            // TODO Auto-generated method stub 

            return new MarginLayoutParams(getContext(), attrs);  
        }  
    }  

2,相关布局的文件引用

    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"  
        xmlns:tools="http://schemas.android.com/tools"  
        android:id="@+id/container"  
        android:layout_width="match_parent"  
        android:layout_height="match_parent" >  

        <com.czm.flowlayout.XCFlowLayout  
            android:id="@+id/flowlayout"  
            android:layout_width="match_parent"  
            android:layout_height="match_parent" >  

        </com.czm.flowlayout.XCFlowLayout>  

    </RelativeLayout>  

可以给个Shape图形背景更美观

三、使用该自定义布局控件类

最后，如何使用该自定义的热门标签控件类呢？很简单，请看下面实例代码：

    package com.czm.flowlayout;  

    import android.app.Activity;  
    import android.graphics.Color;  
    import android.os.Bundle;  
    import android.view.ViewGroup.LayoutParams;  
    import android.view.ViewGroup.MarginLayoutParams;  
    import android.widget.TextView;  
    /** * * @author caizhiming * @created on 2015-4-13 */  
    public class MainActivity extends Activity {  

        private String mNames[] = {  
                "welcome","android","TextView",  
                "apple","jamy","kobe bryant",  
                "jordan","layout","viewgroup",  
                "margin","padding","text",  
                "name","type","search","logcat"  
        };  
        private XCFlowLayout mFlowLayout;  
        @Override  
        protected void onCreate(Bundle savedInstanceState) {  
            super.onCreate(savedInstanceState);  
            setContentView(R.layout.activity_main);  

            initChildViews();  

        }  
        private void initChildViews() {  
            // TODO Auto-generated method stub 
            mFlowLayout = (XCFlowLayout) findViewById(R.id.flowlayout);  
            MarginLayoutParams lp = new MarginLayoutParams(  
                    LayoutParams.WRAP_CONTENT,LayoutParams.WRAP_CONTENT);  
            lp.leftMargin = 5;  
            lp.rightMargin = 5;  
            lp.topMargin = 5;  
            lp.bottomMargin = 5;  
            for(int i = 0; i < mNames.length; i ++){  
                TextView view = new TextView(this);  
                view.setText(mNames[i]);  
                view.setTextColor(Color.WHITE);  
                view.setBackgroundDrawable(getResources().getDrawable(R.drawable.textview_bg));  
                mFlowLayout.addView(view,lp);  
            }  
        }  

    }