简单介绍RecyclerView:
接触过Listview的就知道,相对RecyclerView来说,ListView存在很多不足之处,比如实现点击Item里某个文本或者图片效果,虽然也能实现,不够很复杂,而RecyclerView很好解决了这个问题。并且还能实现瀑布布局,横向布局等。而ListView却无法实现。并且谷歌更加推荐使用RecyclerView。
项目目录如下
第一步:引入官方的依赖库
我这引入的是
compile ‘com.android.support:recyclerview-v7:25.3.1’
注意要与你的项目
compile ‘com.android.support:appcompat-v7:25.3.1’
版本保持一致
下面是我的布局文件
activity_mian.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.recyelerview.MainActivity">
<android.support.v7.widget.RecyclerView
android:id="@+id/recyclerview"
android:layout_width="match_parent"
android:layout_height="match_parent">
</android.support.v7.widget.RecyclerView>
</android.support.constraint.ConstraintLayout>
以及item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="60dp"
android:id="@+id/layout"
android:descendantFocusability="blocksDescendants">
<ImageView
android:id="@+id/image"
android:layout_width="50dp"
android:layout_height="50dp"
android:src="@mipmap/ic_launcher"
android:layout_gravity="center_vertical"/>
<TextView
android:id="@+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="我是内容"
android:layout_gravity="center_vertical"
android:layout_marginLeft="100dp"
android:textColor="#000000"/>
</LinearLayout>
重点代码
第二步定义一个实体类ItemBean
public class ItemBean {
private int IamgeId;
private String Title;
public ItemBean(int IamgeId, String Title) {
this.IamgeId=IamgeId;
this.Title=Title;
}
public int getIamgeId() {
return IamgeId;
}
public void setIamgeId(int iamgeId) {
IamgeId = iamgeId;
}
public String getTitle() {
return Title;
}
public void setTitle(String title) {
Title = title;
}
}
第二步适配器RecyclerViewAdapter
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;
import java.util.List;
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder> {
private List<ItemBean> mList;
public class ViewHolder extends RecyclerView.ViewHolder{
ImageView imageView;
TextView titleTextView;
LinearLayout linearLayout;
public ViewHolder(View view){
super(view);
imageView=(ImageView)view.findViewById(R.id.image);
titleTextView=(TextView)view.findViewById(R.id.title);
linearLayout=(LinearLayout)view.findViewById(R.id.layout);
}
}
//传入展示数据,并且赋值给全局变量
public RecyclerViewAdapter(List<ItemBean> List){
mList=List;
}
//创建ViewHolder实例,将item布局加载出来
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item,parent,false);
ViewHolder holder=new ViewHolder(view);
return holder;
}
//对RecyclerView的子项数据进行赋值
@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
ItemBean itemBean = mList.get(position);
holder.imageView.setImageResource(itemBean.getIamgeId());
holder.titleTextView.setText(itemBean.getTitle());
//点击事件
holder.linearLayout.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int position=holder.getAdapterPosition();
ItemBean itemBean=mList.get(position);
Toast.makeText(v.getContext(),itemBean.getTitle() + "当前位置" + position,Toast.LENGTH_SHORT).show();
}
});
}
//获取RecyclerView有多少子项
@Override
public int getItemCount() {
return mList.size();
}
}
MianActivity
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import java.util.ArrayList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
private RecyclerView recyclerView;
private List<ItemBean> mList=new ArrayList<>();
private RecyclerViewAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
initRecyclerView();
}
private void initRecyclerView() {
initItemBean();//初始化item数据
recyclerView=(RecyclerView)findViewById(R.id.recyclerview);
LinearLayoutManager layoutManager=new LinearLayoutManager(this);
recyclerView.setLayoutManager(layoutManager);
adapter=new RecyclerViewAdapter(mList);
recyclerView.setAdapter(adapter);
}
private void initItemBean() {
for(int i=0;i<10;i++){
ItemBean one= new ItemBean(R.mipmap.ic_launcher, "标题" + i);
mList.add(one);
}
}
}