老婆保佑，代码无BUG
前言
本篇文章，其实很基础，也没什么难度，就是给自己查漏补缺，然后一点一点的积累，
目录
- 一：Adapter的写法
- 二：布局管理器
- LinearLayoutManager
- GridLayoutManager
- StaggeredGridLayoutManager
- 三：分割线
- 添加Android自带的分割线
- 自定义分割线
- 四：ItemAnimator
- 五：指定item的view
引用
compile 'com.android.support:recyclerview-v7:26.1.0'
一：Adapter的写法
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
private ArrayList<String> mData;
public MyAdapter(ArrayList<String> data) {
this.mData = data;
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.view_rv_item, parent, false);
return new ViewHolder(v);
}
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.mTv.setText(mData.get(position));
}
@Override
public int getItemCount() {
return mData == null ? 0 : mData.size();
}
public static class ViewHolder extends RecyclerView.ViewHolder {
TextView mTv;
public ViewHolder(View itemView) {
super(itemView);
mTv = itemView.findViewById(R.id.item_tv);
}
}
}
二：布局管理器
1. LinearLayoutManager
线性管理器，支持横向、纵向。
（1）竖向
//竖向
mLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);
//横向
mLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
mRecyclerView.setLayoutManager(mLayoutManager);
mRecyclerView.setAdapter(mAdapter);
LinearLayoutManager.VERTICAL
对应XML
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/colorAccent"
android:orientation="vertical">
<TextView
android:id="@+id/item_tv"
android:layout_width="match_parent"
android:layout_height="50dp"
android:gravity="center"
android:textColor="#FFF7F7F7"
tools:text="item" />
</LinearLayout>
（2）横向
LinearLayoutManager.HORIZONTAL
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:background="@color/colorAccent"
android:orientation="vertical">
<TextView
android:layout_gravity="center"
android:id="@+id/item_tv"
android:layout_width="50dp"
android:layout_height="match_parent"
android:gravity="center"
android:textColor="#FFF7F7F7"
tools:text="item" />
</LinearLayout>
2. GridLayoutManager
网格布局管理器
mLayoutManager = new GridLayoutManager(this, 4);
mRecyclerView.setLayoutManager(mLayoutManager);
网格布局管理器
3. StaggeredGridLayoutManager
瀑布就式布局管理器
MyStageAdapter myStageAdapter = new MyStageAdapter(getData());
mLayoutManager = new StaggeredGridLayoutManager(3, StaggeredGridLayoutManager.VERTICAL);
mRecyclerView.setLayoutManager(mLayoutManager);
mRecyclerView.setAdapter(myStageAdapter);
瀑布就式布局管理器
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:background="@color/colorAccent">
<TextView
android:id="@+id/id_num"
android:layout_width="100dp"
android:layout_height="100dp"
android:layout_gravity="center"
android:gravity="center"
android:text="1"
android:textColor="#FFF7F7F7" />
</FrameLayout>
package com.allens.recyclerdemo;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import java.util.ArrayList;
import java.util.List;
/**
* 描述:
* <p>
* Created by allens on 2018/1/4.
*/
public class MyStageAdapter extends RecyclerView.Adapter<MyStageAdapter.ViewHolder> {
private ArrayList<String> mData;
private List<Integer> mHeights;
public MyStageAdapter(ArrayList<String> mData) {
this.mData = mData;
mHeights = new ArrayList();
for (int i = 0; i < mData.size(); i++) {
mHeights.add((int) (100 + Math.random() * 300));
}
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View inflate = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_staggered_home, parent, false);
return new ViewHolder(inflate);
}
@Override
public void onBindViewHolder(ViewHolder holder, int position) {
holder.mTv.setText(mData.get(position));
//设置高度
ViewGroup.LayoutParams lp = holder.mTv.getLayoutParams();
lp.height = mHeights.get(position);
holder.mTv.setLayoutParams(lp);
}
@Override
public int getItemCount() {
return mData.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
TextView mTv;
public ViewHolder(View itemView) {
super(itemView);
mTv = itemView.findViewById(R.id.id_num);
}
}
}
三：分割线
1. 添加Android自带的分割线
mRcv.addItemDecoration(new DividerItemDecoration(this,DividerItemDecoration.VERTICAL));
添加Android自带的分割线
2. 自定义分割线
打开DividerItemDecoration看看它的源码
/**
* Sets the {@link Drawable} for this divider.
*
* @param drawable Drawable that should be used as a divider.
*/
public void setDrawable(@NonNull Drawable drawable) {
if (drawable == null) {
throw new IllegalArgumentException("Drawable cannot be null.");
}
mDivider = drawable;
}
我们只需要调用这个方法，然后传入一个Drawable对象
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="rectangle">
<gradient
android:centerColor="#ff00ff00"
android:endColor="#ff0000ff"
android:startColor="#ffff0000"
android:type="linear" />
<size android:height="3dp" />
</shape>
//添加自定义分割线
DividerItemDecoration divider = new DividerItemDecoration(this,DividerItemDecoration.VERTICAL);
divider.setDrawable(ContextCompat.getDrawable(this,R.drawable.rcv_divider));
mRcv.addItemDecoration(divider);
自定义分割线
当然还有一个继承ItemDecoration的方法可以实现，不过我感觉挺麻烦的，具体可以参考
张鸿洋 Android RecyclerView 使用完全解析 体验艺术般的控件
这个有很多东西后期我会写一遍专门讲分割线的文章，先欠着，哈哈
四：ItemAnimator
插入删除的动画效果
mRecyclerView.setItemAnimator(new DefaultItemAnimator());
插入删除的动画效果
五：指定位置的view
View view = mLayoutManager.findViewByPosition(lastIndex);
view.findViewById(R.id.item_left_title).setBackgroundColor(Color.WHITE);
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