安卓基础（点击项目）

代码集合

从数据库把记录好的组件放入组件Arraylist里面（units）

设置units和监听器在unitAdapter适配器里面

unitAdapter.notifyDataSetChanged(); 更新

import com.example.mobileagent.model.RecordedUnit;
import com.example.mobileagent.adapter.UnitAdapter;private List<RecordedUnit> units = new ArrayList<>();
private List<Object> components = new ArrayList<>();// 设置单元列表unitAdapter = new UnitAdapter(this, units, unit -> addUnitToWorkflow(unit));rvUnits.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false));rvUnits.setAdapter(unitAdapter);units.clear();List<RecordedUnit> loadedUnits = dbHelper.getAllRecordedUnits();if (loadedUnits != null) {units.addAll(loadedUnits);}unitAdapter.notifyDataSetChanged();private void addUnitToWorkflow(RecordedUnit unit) {components.add(unit);componentAdapter.notifyItemInserted(components.size() - 1);Toast.makeText(this, "已添加单元: " + unit.getTitle(), Toast.LENGTH_SHORT).show();}

适配器

把RecyclerView.Adapter继承在UnitAdapter里面

类里有静态类static class UnitViewHolder extends RecyclerView.ViewHolder

package com.example.mobileagent.adapter;import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;import com.example.mobileagent.R;
import com.example.mobileagent.model.RecordedUnit;import java.util.List;public class UnitAdapter extends RecyclerView.Adapter<UnitAdapter.UnitViewHolder> {public interface OnItemClickListener {void onItemClick(RecordedUnit unit);}private final Context context;private final List<RecordedUnit> units;private final OnItemClickListener listener;public UnitAdapter(Context context, List<RecordedUnit> units, OnItemClickListener listener) {this.context = context;this.units = units;this.listener = listener;}@NonNull@Overridepublic UnitViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {View view = LayoutInflater.from(context).inflate(R.layout.item_unit, parent, false);return new UnitViewHolder(view);}@Overridepublic void onBindViewHolder(@NonNull UnitViewHolder holder, int position) {RecordedUnit unit = units.get(position);holder.bind(unit, listener);}@Overridepublic int getItemCount() {return units.size();}static class UnitViewHolder extends RecyclerView.ViewHolder {private final TextView titleText;private final TextView coordinatesText;public UnitViewHolder(@NonNull View itemView) {super(itemView);titleText = itemView.findViewById(R.id.tvUnitTitle);coordinatesText = itemView.findViewById(R.id.tvCoordinates);}public void bind(RecordedUnit unit, OnItemClickListener listener) {titleText.setText(unit.getTitle());coordinatesText.setText(String.format("X=%.1f, Y=%.1f", unit.getX(), unit.getY()));itemView.setOnClickListener(v -> {if (listener != null) {listener.onItemClick(unit);}});}}
} 

xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"xmlns:app="http://schemas.android.com/apk/res-auto"android:layout_width="150dp"android:layout_height="match_parent"android:layout_margin="4dp"app:cardCornerRadius="8dp"app:cardElevation="2dp"app:cardBackgroundColor="#E8F5E9"><LinearLayoutandroid:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"android:padding="8dp"android:gravity="center"><TextViewandroid:id="@+id/tvUnitTitle"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="单元标题"android:textSize="16sp"android:textStyle="bold"android:maxLines="1"android:ellipsize="end"android:gravity="center"android:textColor="#333333"android:layout_marginBottom="8dp"/><TextViewandroid:id="@+id/tvCoordinates"android:layout_width="match_parent"android:layout_height="wrap_content"android:text="X=0, Y=0"android:textSize="14sp"android:textColor="#333333"android:gravity="center"/><TextViewandroid:layout_width="match_parent"android:layout_height="wrap_content"android:text="点击添加"android:textSize="12sp"android:textColor="#0066CC"android:gravity="center"android:layout_marginTop="8dp"/></LinearLayout></androidx.cardview.widget.CardView>