- 创建RecyclerView的布局文件activity_recycler.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent">
<androidx.recyclerview.widget.RecyclerView
android:id="@+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>
- 创建单条item的布局文件activity_recycler_item.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent" android:layout_height="match_parent"
android:paddingTop="5dp">
<TextView
android:id="@+id/coursename"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="16sp"
android:textStyle="bold"
android:layout_marginStart="110dp"
android:ellipsize="end"
android:singleLine="true" />
<TextView
android:id="@+id/teachername"
android:layout_below="@id/coursename"
android:textSize="16sp"
android:layout_marginStart="110dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ellipsize="end"
android:singleLine="true" />
<TextView
android:id="@+id/studentnum"
android:textSize="16sp"
android:layout_below="@id/teachername"
android:layout_marginStart="110dp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ellipsize="end"
android:singleLine="true" />
<ImageView
android:id="@+id/courselogo"
android:layout_width="100dp"
android:layout_height="65dp"
android:layout_marginStart="5dp"
android:scaleType="centerCrop"
android:contentDescription="@string/app_name" />
<View
android:layout_below="@id/courselogo"
android:layout_width="match_parent"
android:layout_height="1dp"
android:layout_marginTop="5dp"
android:layout_marginBottom="5dp"
android:background="@color/colorPrimary"/>
</RelativeLayout>
- 创建RecyclerView的activity类
package com.iefeel.yudemo;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import com.iefeel.tools.YuRecyclerAdapter;
import com.mumu.dialog.MMAlertDialog;
import java.util.ArrayList;
import java.util.HashMap;
public class RecyclerActivity extends BaseActivity {
//定义数组以填充数据
private String[][] coursedata = {
{"722", "物联网硬件基础1", "教师三", "1111", "http://xuexi.iefeel.com/userfiles/logo/201903/30/7e723fc7a3aa607502c502b6f9fc2ea7_s.jpg"},
{"720", "基于LabVIEW的物联网程序设计", "教师二", "2222", "http://xuexi.iefeel.com/userfiles/logo/201903/30/7710e65597136cdd3465e2211edeb90f_s.jpg"},
{"658", "建筑装饰表现技法", "教师一", "3333", "http://xuexi.iefeel.com/public/images/course.png"}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_recycler);
//定义一个HashMap构成的列表以键值对的方式存放数据
ArrayList<HashMap<String, Object>> listItem = new ArrayList<>();
//循环填充数据
for(int i=0;i<coursedata.length;i++){
HashMap<String,Object> map = new HashMap<>();
map.put("courseid", coursedata[i][0]);
map.put("coursename", coursedata[i][1]);
map.put("teachername", "主讲：" + coursedata[i][2]);
map.put("studentnum", "学员：" + coursedata[i][3]);
map.put("courselogo", coursedata[i][4]);
listItem.add(map);
}
RecyclerView recyclerv = findViewById(R.id.recycler_view);
LinearLayoutManager layomanager = new LinearLayoutManager(this);
recyclerv.setLayoutManager(layomanager);
YuRecyclerAdapter madapter = new YuRecyclerAdapter(RecyclerActivity.this, listItem);
recyclerv.setAdapter(madapter);
madapter.setOnItemClickListener(new YuRecyclerAdapter.OnItemClickListener() {
@Override
public void onItemClick(View view, int Position) {
String s = listItem.get(Position).toString();
MMAlertDialog.showDialog(RecyclerActivity.this,
"这是第"+ (Position+1) +"个item",
s,
null,
"确定",
false,
null,
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Toast.makeText(RecyclerActivity.this, "确定", Toast.LENGTH_SHORT).show();
dialog.dismiss();
}
});
}
});
}
}
- 自定义RecyclerView的adapter
package com.iefeel.tools;
import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ImageView;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import com.iefeel.yudemo.R;
public class YuRecyclerAdapter extends RecyclerView.Adapter<YuRecyclerAdapter.YuViewHolder> {
//当前上下文对象
Context context;
//RecyclerView填充Item数据的List对象
ArrayList<HashMap<String, Object>> datas;
private YuViewHolder holder;
RemoteImageHelper imghelper = new RemoteImageHelper();
public YuRecyclerAdapter(Context context, ArrayList<HashMap<String, Object>> datas){
this.context = context;
this.datas = datas;
}
//创建ViewHolder
@NonNull
@Override
public YuViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
//实例化得到Item布局文件的View对象
View v = View.inflate(context, R.layout.activity_recycler_item,null);
//返回YuViewHolder的对象
return new YuViewHolder(v);
}
private OnItemClickListener mItemClickListener;
//item的回调接口
public interface OnItemClickListener {
void onItemClick(View view, int Position);
}
//定义一个设置点击监听器的方法
public void setOnItemClickListener(OnItemClickListener itemClickListener) {
this.mItemClickListener = itemClickListener;
}
//绑定数据
@Override
public void onBindViewHolder(@NonNull YuViewHolder holder, int position) {
holder.coursename.setText(datas.get(position).get("coursename").toString());
holder.teachername.setText(datas.get(position).get("teachername").toString());
holder.studentnum.setText(datas.get(position).get("studentnum").toString());
imghelper.loadImage(holder.courselogo, datas.get(position).get("courselogo").toString());
//如果设置了回调，则设置点击事件
if (mItemClickListener != null) {
holder.itemView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
mItemClickListener.onItemClick(holder.itemView, position);
}
});
}
}
//返回Item的数量
@Override
public int getItemCount() {
return datas.size();
}
//继承RecyclerView.ViewHolder抽象类的自定义ViewHolder
class YuViewHolder extends RecyclerView.ViewHolder{
TextView coursename;
TextView teachername;
TextView studentnum;
ImageView courselogo;
public YuViewHolder(View itemView) {
super(itemView);
coursename = itemView.findViewById(R.id.coursename);
teachername = itemView.findViewById(R.id.teachername);
studentnum = itemView.findViewById(R.id.studentnum);
courselogo = itemView.findViewById(R.id.courselogo);
}
}
}
- 获取网络图片辅助类
package com.iefeel.tools;
import android.graphics.drawable.Drawable;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.widget.ImageView;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.HashMap;
import java.util.Map;
import com.iefeel.yudemo.R;
public class RemoteImageHelper {
private final Map<String, Drawable> cache = new HashMap<String, Drawable>();
public void loadImage(final ImageView imageView, final String urlString) {
loadImage(imageView, urlString, true);
}
public void loadImage(final ImageView imageView, final String urlString, boolean useCache) {
if (useCache && cache.containsKey(urlString)) {
imageView.setImageDrawable(cache.get(urlString));
}
//You may want to show a "Loading" image here
imageView.setImageResource(R.drawable.ic_launcher);
//Log.d(this.getClass().getSimpleName(), "Image url:" + urlString);
final Handler handler = new Handler() {
@Override
public void handleMessage(Message message) {
imageView.setImageDrawable((Drawable) message.obj);
}
};
Runnable runnable = new Runnable() {
public void run() {
Drawable drawable = null;
try {
InputStream is = download(urlString);
drawable = Drawable.createFromStream(is, "src");
if (drawable != null) {
cache.put(urlString, drawable);
}
} catch (Exception e) {
Log.e(this.getClass().getSimpleName(), "Image download failed", e);
//Show "download fail" image
drawable = imageView.getResources().getDrawable(R.drawable.ic_launcher);
}
//Notify UI thread to show this image using Handler
Message msg = handler.obtainMessage(1, drawable);
handler.sendMessage(msg);
}
};
new Thread(runnable).start();
}
/**
* Download image from given url.
* Make sure you have "android.permission.INTERNET" permission set in AndroidManifest.xml.
*
* @param urlString
* @return
* @throws MalformedURLException
* @throws IOException
*/
private InputStream download(String urlString) throws MalformedURLException, IOException {
InputStream inputStream = (InputStream) new URL(urlString).getContent();
return inputStream;
}
}
-
运行结果
RecyclerView效果图.jpg
- item点击事件
RecyclerView点击事件.jpg
更多内容点此查看。
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