Android使用RecyclerView实现瀑布流

核心代码：Adapter类：

package com.mcxtzhang.demo;

import android.content.Context;

import android.util.Log;

import android.view.View;

import android.view.ViewGroup;

import java.util.HashMap;

import java.util.List;

import java.util.Map;

/**

* Created by Administrator on 2015/12/26.

*/

public class StaggeredAdapter extends MyAdapter {

/*private List<Integer> mHeights;//竖直瀑布流

private List<Integer> mWidths;//水平瀑布流*/

private Map<Integer,Integer> mHeights;

private Map<Integer,Integer> mWidths;

private boolean isVertical = true;

public void setIsVertical(boolean isVertical) {

this.isVertical = isVertical;

}

public StaggeredAdapter(Context context, List<DataBean> datas) {

super(context, datas);

//设置竖直瀑布流的height集合值:

//设置水平瀑布流的height集合值:

mWidths = new HashMap<Integer,Integer>();

mHeights = new HashMap<Integer,Integer>();

onDataChanged();

}

//设置水平瀑布流的height集合值: 如果有该值 则不重复创建

private void setStaggeredWidth() {

if (null != mDatas && 0 != mDatas.size()){

for(int i=0;i<mDatas.size();i++){

if(null==mWidths.get(mDatas.get(i).id)){

mWidths.put(mDatas.get(i).id,(int)(100 + Math.random() * 300));

}

}

}

}

//设置竖直瀑布流的height集合值:

private void setStaggeredHeight() {

Log.i(TAG,"setStaggeredHeight()");

if (null != mDatas && 0 != mDatas.size()){

Log.i(TAG,"null != mDatas && 0 != mDatas.size()()");

for(int i=0;i<mDatas.size();i++){

Log.i(TAG,"mHeights.get(mDatas.get(i).id):"+mHeights.get(mDatas.get(i).id));

if(null==mHeights.get(mDatas.get(i).id)){

Log.i(TAG,"null!=mHeights.get(mDatas.get(i).id)");

mHeights.put(mDatas.get(i).id, (int) (100 + Math.random() * 300));

}

}

}

}

//数据改变后要执行的操作的封装 b

public void onDataChanged(){

//设置竖直瀑布流的height集合值:

setStaggeredHeight();

//设置水平瀑布流的height集合值:

setStaggeredWidth();

}

@Override

public MyViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {

Log.i(TAG, "onCreateViewHolder:"+i);

View v = mInflater.inflate(R.layout.item_staggered, viewGroup, false);

/*//瀑布流 错误写法 因为每次都会onbindviewholder 但不是每次都是create

ViewGroup.LayoutParams params = v.getLayoutParams();

params.height = mHeights.get(i);

v.setLayoutParams(params);

//瀑布流*/

return new MyViewHolder(v);

}

@Override

public void onBindViewHolder(MyViewHolder viewHolder, int i) {

super.onBindViewHolder(viewHolder,i);

Log.i(TAG, "onBindViewHolder:" + i);

//竖直瀑布流

if(isVertical){

ViewGroup.LayoutParams params = viewHolder.itemView.getLayoutParams();

int temp = mDatas.get(i).id;

Log.i(TAG, "temp:" + temp +"mHeights:"+mHeights);

int temp2 = mHeights.get(temp);

params.height =temp2;

viewHolder.itemView.setLayoutParams(params);

}

//竖直瀑布流

//水平瀑布流

else{

ViewGroup.LayoutParams params = viewHolder.itemView.getLayoutParams();

params.width = mWidths.get(mDatas.get(i).id);

viewHolder.itemView.setLayoutParams(params);

}

//水平瀑布流

}

//重写父类 否则增加后会越界异常

@Override

public void addData(int pos, DataBean data) {

super.addData(pos, data);

onDataChanged();

}

@Override

public void removeData(int pos) {

super.removeData(pos);

onDataChanged();

}

}

Activity:

package com.mcxtzhang.demo;

import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;

import android.support.v7.widget.DefaultItemAnimator;

import android.support.v7.widget.RecyclerView;

import android.support.v7.widget.StaggeredGridLayoutManager;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.widget.Toast;

import java.util.ArrayList;

import java.util.List;

public class StaggeredActivity extends AppCompatActivity {

private RecyclerView mRecyclerView;

private List<DataBean> mDatas;

private StaggeredAdapter mAdapter;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

initDatas();

initViews();

}

private void initViews() {

mRecyclerView = (RecyclerView) findViewById(R.id.recyclerview);

mAdapter = new StaggeredAdapter(StaggeredActivity.this,mDatas);

mRecyclerView.setAdapter(mAdapter);

//设置REcyclerVIew布局管理

//三个参数context，水平/竖直排列数据 ，是否反向显示。

/*RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(StaggeredActivity.this, LinearLayoutManager.VERTICAL, true);

mRecyclerView.setLayoutManager(layoutManager);*/

//设置RecyclerView的Item分割线

//想改变分割线的样式 ，要定义一个drawable，然后在style里覆盖android:listDivider 属性

//mRecyclerView.addItemDecoration(new DividerItemDecoration(MainActivity.this, DividerItemDecoration.VERTICAL_LIST));

//瀑布流

mRecyclerView.setLayoutManager(new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL));

//设置动画

mRecyclerView.setItemAnimator(new DefaultItemAnimator());

//设置点击事件

mAdapter.setOnClickEventListener(new MyAdapter.onClickEventListener() {

@Override

public void onClickListener(View v, int pos) {

Toast.makeText(StaggeredActivity.this, "pos:" + pos, Toast.LENGTH_SHORT).show();

}

@Override

public void onLongClickListener(View v, int pos) {

Toast.makeText(StaggeredActivity

.this,"long pos:"+pos,Toast.LENGTH_SHORT).show();

mAdapter.removeData(pos);

}

});

//下面的方法不行 必须用上面的layoutmanager

//mRecyclerView.setLayoutManager(new GridLayoutManager(StaggeredActivity.this,3));

}

private void initDatas() {

mDatas = new ArrayList<DataBean>();

for (int i = 'A'; i <= 'z'; i++) {

mDatas.add(new DataBean(i,"" + (char) i));

}

}

@Override

public boolean onCreateOptionsMenu(Menu menu) {

// Inflate the menu; this adds items to the action bar if it is present.

getMenuInflater().inflate(R.menu.menu_staggered, menu);

return true;

}

@Override

public boolean onOptionsItemSelected(MenuItem item) {

int id = item.getItemId();

//noinspection SimplifiableIfStatement

switch (id) {

case R.id.action_staggered_vertical:

mAdapter.setIsVertical(true);

mRecyclerView.setLayoutManager(new StaggeredGridLayoutManager(3,StaggeredGridLayoutManager.VERTICAL));

break;

case R.id.action_staggered_horizontal:

//水平瀑布流

mAdapter.setIsVertical(false);

mRecyclerView.setLayoutManager(new StaggeredGridLayoutManager(4,StaggeredGridLayoutManager.HORIZONTAL));

break;

//增加一个选项:

case R.id.action_add:

mAdapter.addData(1,new DataBean(1,"刁"));

break;

//删除一个选项:

case R.id.action_delete:

mAdapter.removeData(1);

break;

default:

break;

}

return super.onOptionsItemSelected(item);

}

}

Bean:

package com.mcxtzhang.demo;

/**

* Created by Administrator on 2015/12/26.

*/

public class DataBean {

public int id;

public String title;

public DataBean(int id, String title) {

this.id = id;

this.title = title;

}

}