Android：如何在自定义RecyclerView Adapter中获取MatchActivity的正确引用以调用其Getter方法

兄弟，你现在的问题根源太明显了——你在onBindViewHolder()里直接new MatchActivity()，这根本不是当前正在运行的那个Activity实例啊！这个新创建的对象里的集合大概率是空的，或者和当前页面的真实数据完全不匹配，自然会触发IndexOutOfBoundsException。下面给你几个靠谱的解决办法：

方法一：直接传递Activity的引用（简单直接，但要注意内存泄漏） #

1. 修改Adapter的构造函数 #

在MatchActivityPlayerAdapter里添加一个MatchActivity类型的成员变量，然后修改构造函数接收这个引用：

private final List<Player> playerList;
private final Match match;
private final MatchActivity matchActivity; // 持有Activity引用

// 更新构造函数
MatchActivityPlayerAdapter(List<Player> playerList, Match match, MatchActivity matchActivity) {
    this.playerList = playerList;
    this.match = match;
    this.matchActivity = matchActivity;
}

2. 在MatchActivity中创建Adapter时传入自身引用 #

当你在MatchActivity里初始化Adapter的时候，把this传进去：

// 假设这是你初始化RecyclerView和Adapter的代码
MatchActivityPlayerAdapter adapter = new MatchActivityPlayerAdapter(playerList, yourMatchInstance, this);
yourRecyclerView.setAdapter(adapter);

3. 修复onBindViewHolder中的代码 #

现在直接用传递过来的Activity引用，不要再new对象了，同时记得加个索引判断避免越界：

@Override
public void onBindViewHolder(@NonNull MatchActivityPlayerRowViewHolder holder, int position) {
    final Player player = playerList.get(position);
    
    // 用传递过来的真实Activity引用
    holder.nameTextView.setText(player.getPlayerName());
    
    // 先判断索引是否合法，避免再次触发越界异常
    if (position >= 0 && position < matchActivity.getRemainingPoints().size()) {
        holder.pointsTextView.setText(String.valueOf(matchActivity.getRemainingPoints().get(position)));
        holder.dart1.setText(String.valueOf(matchActivity.getDart1().get(position)));
        holder.dart2.setText(String.valueOf(matchActivity.getDart2().get(position)));
        holder.dart3.setText(String.valueOf(matchActivity.getDart3().get(position)));
        holder.dartsCombined.setText(String.valueOf(matchActivity.getDartsCombined().get(position)));
    }
    // holder.averageTextView.setText(matchActivity.getAverage().get(position));
}

方法二：传递数据而非Activity引用（更推荐，解耦+避免内存泄漏） #

直接让Adapter持有Activity引用可能会导致内存泄漏（比如Activity销毁后Adapter还持有它的引用），更优雅的方式是把Adapter需要的数据直接传递过去，让Adapter只负责渲染数据，不依赖Activity：

1. 修改Adapter构造函数，直接接收所需数据 #

private final List<Player> playerList;
private final Match match;
private final List<Integer> remainingPoints;
private final List<Integer> dart1;
private final List<Integer> dart2;
private final List<Integer> dart3;
private final List<Integer> dartsCombined;

// 更新构造函数，直接接收所有需要渲染的数据
MatchActivityPlayerAdapter(List<Player> playerList, Match match,
                           List<Integer> remainingPoints, List<Integer> dart1,
                           List<Integer> dart2, List<Integer> dart3, List<Integer> dartsCombined) {
    this.playerList = playerList;
    this.match = match;
    this.remainingPoints = remainingPoints;
    this.dart1 = dart1;
    this.dart2 = dart2;
    this.dart3 = dart3;
    this.dartsCombined = dartsCombined;
}

2. 在MatchActivity中创建Adapter时传入数据 #

MatchActivityPlayerAdapter adapter = new MatchActivityPlayerAdapter(
    playerList, 
    yourMatchInstance,
    getRemainingPoints(),
    getDart1(),
    getDart2(),
    getDart3(),
    getDartsCombined()
);
yourRecyclerView.setAdapter(adapter);

3. 修改onBindViewHolder代码 #

现在直接用传入的数据列表即可：

@Override
public void onBindViewHolder(@NonNull MatchActivityPlayerRowViewHolder holder, int position) {
    final Player player = playerList.get(position);
    
    holder.nameTextView.setText(player.getPlayerName());
    
    if (position >= 0 && position < remainingPoints.size()) {
        holder.pointsTextView.setText(String.valueOf(remainingPoints.get(position)));
        holder.dart1.setText(String.valueOf(dart1.get(position)));
        holder.dart2.setText(String.valueOf(dart2.get(position)));
        holder.dart3.setText(String.valueOf(dart3.get(position)));
        holder.dartsCombined.setText(String.valueOf(dartsCombined.get(position)));
    }
}

这样做的好处是Adapter和Activity完全解耦，既避免了内存泄漏风险，也让Adapter的复用性更强。

内容的提问来源于stack exchange，提问作者Blaupunkt