heh*_*ehe 1 java generics android
我看到了这个问题的答案,
Java:如何创建一个泛型类,它需要一个扩展类并实现接口的数据类型?
所以我试图为recyclerview 创建一个基础适配器.这是我的基本适配器的完整代码:
class BaseAdapter<T extends SugarRecord & ModelInterface> extends RecyclerView.Adapter<BaseAdapter.ViewHolder> {
protected SparseArray<T> modelSparseArray;
protected Context context;
private int backgroundResource;
public BaseAdapter(SparseArray<T> modelSparseArray, Context context) {
this.modelSparseArray = modelSparseArray;
this.context = context;
setupBackgroundResource(context);
}
private void setupBackgroundResource(Context context){
TypedValue typedValue = new TypedValue();
context.getTheme().resolveAttribute(R.attr.selectableItemBackground, typedValue, true);
backgroundResource = typedValue.resourceId;
}
public class ViewHolder extends RecyclerView.ViewHolder{
@Bind(R.id.done_indicator)
CheckBox doneIndicator;
@Bind(R.id.title)
TextView title;
View view;
public ViewHolder(View itemView) {
super(itemView);
ButterKnife.bind(this, itemView);
view = itemView;
}
}
public void addModel(T model){
int key = model.getId().intValue();
int index = modelSparseArray.indexOfKey(key);
modelSparseArray.append(key, model);
if(key < 0)
notifyItemInserted(modelSparseArray.size());
else
notifyItemChanged(index);
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.row_layout, parent, false);
view.setBackgroundResource(backgroundResource);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(ViewHolder holder, final int position) {
final T model = modelSparseArray.valueAt(position);
holder.title.setText(model.getTitle());
holder.doneIndicator.setChecked(model.isDone());
holder.doneIndicator.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
model.setDone(isChecked);
model.save();
}
});
}
@Override
public int getItemCount() {
return modelSparseArray.size();
}
}
Run Code Online (Sandbox Code Playgroud)
这个问题几乎与我提出的问题完全相同,但是,该问题的OP给出了使用a的问题的答案pastebin,遗憾的是,该链接不再起作用.
错误是:
Error:(24, 1) error: BaseAdapter is not abstract and does not override abstract method onBindViewHolder(BaseAdapter.ViewHolder,int) in Adapter
Error:(80, 5) error: method does not override or implement a method from a supertype
Run Code Online (Sandbox Code Playgroud)
第一个错误指向类声明的开头,第二个错误指向Override上面的错误onBindViewHolder
所以我在发布问题后立即发现了答案,我会发布这个以防万一有人需要答案:
更改RecyclerView.Adapter<BaseAdapter.ViewHolder>到RecyclerView.Adapter<BaseAdapter<T>.ViewHolder>
我最初创建了没有type参数的基本适配器,所以它可以使用RecyclerView.Adapter<BaseAdapter.ViewHolder>,但是在添加了type参数之后,我还需要添加<T>.
另一个解决方案是ViewHolder建议内部静态为@chRyNaN.
| 归档时间: |
|
| 查看次数: |
721 次 |
| 最近记录: |