瀑布流的实现

Xml布局文件：

<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    xmlns:app="http://schemas.android.com/apk/res-auto"     android:layout_width="match_parent"    android:layout_height="match_parent"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin" ><company.com.StaggeredGridView.StaggeredGridView    android:id="@+id/grid_view"    android:layout_width="match_parent"    android:layout_height="match_parent"    app:column_count_landscape="2"    app:column_count_portrait="3"    app:item_margin="8dp"/></RelativeLayout>

MainActivity中的代码：

package company.com.staggeredgrid;import android.app.Activity;import android.graphics.Color;import android.os.Bundle;import android.util.SparseArray;import android.util.TypedValue;import android.view.Gravity;import android.view.View;import android.view.ViewGroup;import android.widget.AdapterView;import android.widget.BaseAdapter;import android.widget.TextView;import android.widget.Toast;import java.util.Random;import company.com.StaggeredGridView.ExtendableListView;import company.com.StaggeredGridView.StaggeredGridView;public class MainActivity extends Activity implements AdapterView.OnItemClickListener{    private StaggeredGridView staggeredGridView;    private final Random mRandom=new Random();    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.content_main);        initView();        setAdapter();        AddListener();    }    private void AddListener() {   staggeredGridView.setOnItemClickListener(this);    }    private void setAdapter() {        staggeredGridView.setAdapter(new MyAdapter());    }    private void initView() {       staggeredGridView= (StaggeredGridView)findViewById(R.id.grid_view);    }   //添加瀑布流的点击事件    @Override    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {                Toast.makeText(MainActivity.this,"点击了"+position,Toast.LENGTH_SHORT).show();    }//自定义适配器，为瀑布上添加文本    private class MyAdapter extends BaseAdapter {        @Override        public int getCount() {            return DATA.length;        }        @Override        public Object getItem(int position) {            return DATA[position];        }        @Override        public long getItemId(int position) {            return position;        }        @Override        public View getView(int position, View convertView, ViewGroup parent) {            if (convertView == null) {                convertView = new TextView(MainActivity.this);                //设置view的长宽属性                ExtendableListView.LayoutParams lp=new ExtendableListView.LayoutParams(ExtendableListView.LayoutParams.WRAP_CONTENT, ExtendableListView.LayoutParams.WRAP_CONTENT);                convertView.setLayoutParams(lp);            }            TextView view = (TextView) convertView;            view.setText(DATA[position]);            view.setBackgroundColor(COLOR[position % 5]);            view.setTextSize(TypedValue.COMPLEX_UNIT_SP, 15);            view.setGravity(Gravity.BOTTOM);            view.setTextColor(Color.WHITE);            ExtendableListView.LayoutParams lp= (ExtendableListView.LayoutParams) view.getLayoutParams();            lp.height= (int) (getPositionRatio(position)*200);            view.setLayoutParams(lp);            return view;        }    }    //瀑布流的背景颜色    private static final int[] COLOR = new int[] {            0xff33b5e5, 0xffaa66cc, 0xff99cc00, 0xffffbb33, 0xffff4444    };    //瀑布流上显示的文本    private static final String[] DATA = new String[] {            "Love", "Love", "Love", "Love", "Love",            "Love", "Love", "Love", "Love", "Love", "ALove",            "Love", "Love", "Love", "Love", "Love",            "Love", "name", "love", "Anthoriro", "love",            "name", "name", "you", "Armenian String", "name",            "Asadero", "Asiago", "Love", "Autun", "Love", "Baby Swiss",            "Love", "you", "Love", "you", "for", "much", "Banon",            "love", "Basing", "Love", "Love", "love",            "love", "much", "for"    };    //此方法用在计算项高，根据位置得到一个随机的比例    private static final SparseArray<Double> sPositionHeightRatios = new SparseArray<Double>();    private double getPositionRatio(final int position) {        double ratio = sPositionHeightRatios.get(position, 0.0);        if (ratio == 0) {            ratio = getRandomHeightRatio();            sPositionHeightRatios.append(position, ratio);        }        return ratio;    }    private double getRandomHeightRatio() {        return (mRandom.nextDouble() / 2.0) + 1.0; // height will be 1.0 - 1.5 the width    }}

因为StaggeredGridView也继承自AbsListView，所以和ListView、GridView的用法完全一样。

完整项目中的util中提供了两个DynamicHeightImageview和DynamicHeightTextView，这两个视图就是如果指定了宽高比，会在绘制的时候保持该比例，具体代码如下：

@Override      protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {          if (mHeightRatio > 0.0) {              // set the image views size              int width = MeasureSpec.getSize(widthMeasureSpec);              int height = (int) (width * mHeightRatio);              setMeasuredDimension(width, height);          }          else {              super.onMeasure(widthMeasureSpec, heightMeasureSpec);          }      } 

点击此处下载完整Demo;