这次学习的内容是使用RecyclerView来实现一些较为复杂的布局,比如一个item:
最左边是一个imageview,中间部分为textView,textView下面又是一个textView,最右边为一个imageview。
1、首先在activity_main.xml中添加RecyclerView,随后正如之前所说的分别针对左中右新建3个XML布局文件命名为item_type_one、two、three.随后对其进行布局配置。
2、新建一个adapter添加模拟数据。然后针对布局新建三个viewholder。随后新建一个抽象类TypeAbstractViewHolder,将三个viewholder用到的同一个方法封装起来调用,将三个viewHolder继承自抽象类。为了优雅。
activity_main.xml:
item_type_one.xml:
item_type_two.xml:
item_type_three.xml:
这边提一个小技巧,一般textview如果不设置文本内容的话是无法预览的,这里我们在属性中添加一个:tools:text=”abc”;
这个时候abc就会在UI上面显示出来了,而且abc也不用加入string.xml.
Java文件:
MAinActivity.class
package com.example.tony.recyclerviewdemo;
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 mRecyclerView;
private DemoAdapter mAdapter;
int colors[] = {android.R.color.holo_blue_light,
android.R.color.holo_orange_light,
android.R.color.holo_red_light};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mRecyclerView = (RecyclerView) findViewById(R.id.recycleView);
mRecyclerView.setLayoutManager(new LinearLayoutManager(this,
LinearLayoutManager.VERTICAL, false));
mAdapter = new DemoAdapter(this);
mRecyclerView.setAdapter(mAdapter);
initData();
}
private void initData() {
List list = new ArrayList<>();
for (int i = 0; i < 20; i++) {
int type = (int) (Math.random() * 3 + 1);
DataModel data = new DataModel();
data.avatarColor = colors[type - 1];
data.type = type;
data.name = "Name: " + i;
data.content = "Content: " + i;
data.contentColor = colors[(type + 1) % 3];
list.add(data);
}
mAdapter.addList(list);
mAdapter.notifyDataSetChanged();
}
}
DemoAdapter.class
package com.example.tony.recyclerviewdemo; import android.content.Context; import android.support.v7.widget.RecyclerView; import android.view.LayoutInflater; import android.view.ViewGroup; import java.util.ArrayList; import java.util.List; public class DemoAdapter extends RecyclerView.Adapter{ private LayoutInflater mLayoutInflater; private List mList = new ArrayList<>(); public DemoAdapter(Context context) { mLayoutInflater = LayoutInflater.from(context); } public void addList(List list) { mList.addAll(list); } @Override public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { switch (viewType) { case DataModel.TYPE_ONE: return new TypeoneViewHolder(mLayoutInflater.inflate(R.layout.item_type_one, parent, false)); case DataModel.TYPE_TWO: return new TypeTwoViewHolder(mLayoutInflater.inflate(R.layout.item_type_two, parent, false)); case DataModel.TYPE_THREE: return new TypeThreeViewHolder(mLayoutInflater.inflate(R.layout.item_type_three, parent, false)); } return null; } @Override public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) { ((TypeAbstractViewHolder) holder).bindHolder(mList.get(position)); } @Override public int getItemViewType(int position) { return mList.get(position).type; } @Override public int getItemCount() { return mList.size(); } }
DataModel.class
package com.example.tony.recyclerviewdemo;
public class DataModel {
public static final int TYPE_ONE = 1;
public static final int TYPE_TWO = 2;
public static final int TYPE_THREE = 3;
public int type;
public int avatarColor;
public String name;
public String content;
public int contentColor;
}
TypeAbstractViewHolder.class
package com.example.tony.recyclerviewdemo;
import android.support.v7.widget.RecyclerView;
import android.view.View;
public abstract class TypeAbstractViewHolder extends RecyclerView.ViewHolder{
public TypeAbstractViewHolder(View itemView) {
super(itemView);
}
public abstract void bindHolder(DataModel model);
}
TypeOneViewHolder.class
package com.example.tony.recyclerviewdemo;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
public class TypeoneViewHolder extends TypeAbstractViewHolder {
private ImageView avatar;
private TextView name;
public TypeoneViewHolder(View itemView) {
super(itemView);
avatar = (ImageView) itemView.findViewById(R.id.avatar);
name = (TextView) itemView.findViewById(R.id.name);
}
//ViewHolder数据和外面数据绑定起来
@Override
public void bindHolder(DataModel model) {
avatar.setBackgroundResource(model.avatarColor);
name.setText(model.name);
}
}
TypeTwoViewHolder.class
package com.example.tony.recyclerviewdemo;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
public class TypeTwoViewHolder extends TypeAbstractViewHolder {
private ImageView avatar;
private TextView name;
private TextView content;
public TypeTwoViewHolder(View itemView) {
super(itemView);
avatar = (ImageView) itemView.findViewById(R.id.avatar);
name = (TextView) itemView.findViewById(R.id.name);
content = (TextView) itemView.findViewById(R.id.content);
}
//ViewHolder数据和外面数据绑定起来
@Override
public void bindHolder(DataModel model) {
avatar.setBackgroundResource(model.avatarColor);
name.setText(model.name);
content.setText(model.content);
}
}
TypeThreeViewHolder.class
package com.example.tony.recyclerviewdemo;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
public class TypeThreeViewHolder extends TypeAbstractViewHolder {
private ImageView avatar;
private TextView name;
private TextView content;
private ImageView contentImage;
public TypeThreeViewHolder(View itemView) {
super(itemView);
avatar = (ImageView) itemView.findViewById(R.id.avatar);
contentImage = (ImageView) itemView.findViewById(R.id.contentImage);
name = (TextView) itemView.findViewById(R.id.name);
content = (TextView) itemView.findViewById(R.id.content);
}
//ViewHolder数据和外面数据绑定起来
@Override
public void bindHolder(DataModel model) {
avatar.setBackgroundResource(model.avatarColor);
name.setText(model.name);
contentImage.setBackgroundResource(model.contentColor);
content.setText(model.content);
}
}
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持考高分网。



