Android自定义列表适配器总是删除最后一项

Question

日安，

我正在尝试更新我对android编程的知识。

通过创建一个带有自定义适配器列表的简单备忘录应用程序。

我的问题是，即使我叫“NotifyDataSetChanged()”，

在我的列表中删除的值总是最后一个。

虽然当我刷新它时，它将显示正确的。

这是我的代码：

public class CustomAdapter extends BaseAdapter{   
List<Memo> memos;
Context context;
int [] imageId;


private static LayoutInflater inflater = null;
public CustomAdapter(MainActivity mainActivity, List<Memo> _memos) {
    memos = _memos;
    context = mainActivity;
    inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
@Override
public int getCount() {
    return memos.size();
}

@Override
public Object getItem(int position) {
    return position;
}

@Override
public long getItemId(int position) {
    return position;
}

public class Holder
{
    TextView tv;
    TextView tv2;
    Button deleteMemoBtn;
}

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    Holder mViewHolder = null;

    if (convertView == null) {
        mViewHolder = new Holder();
        LayoutInflater vi = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        convertView = vi.inflate(R.layout.list_memo, parent, false);
        mViewHolder.tv = (TextView) convertView.findViewById(R.id.textView1);
        mViewHolder.tv2 = (TextView) convertView.findViewById(R.id.textView2);
        mViewHolder.deleteMemoBtn = (Button) convertView.findViewById(R.id.deleteMemoBtn);

        mViewHolder.tv.setText(memos.get(position).getMemoTitle());
        mViewHolder.tv2.setText(Integer.toString(memos.get(position).getMemoID()));

        mViewHolder.tv.setOnClickListener(new OnClickListener() {            
            @Override
            public void onClick(View v) {
                Toast.makeText(context, "You Clicked " + memos.get(position).getMemoTitle(), Toast.LENGTH_LONG).show();
            }
        });  



        mViewHolder.deleteMemoBtn.setOnClickListener(new OnClickListener() {            
            @Override
            public void onClick(View v) {
                Toast.makeText(context, "deleted " + Integer.toString(position), Toast.LENGTH_LONG).show();   
                memos.remove(position);
                notifyDataSetChanged();
            }
        });  


    }
    return convertView;
}


} 

希望有人能让我明白为什么这段代码不起作用。

谢谢!

Answer 1

试试这段代码。

public class CustomAdapter extends BaseAdapter {
    List<Memo> memos;
    Context context;
    int[] imageId;


    private LayoutInflater inflater = null;

    public CustomAdapter(Context mainActivity, List<Memo> _memos) {
        memos = _memos;
        context = mainActivity;
        inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

    @Override
    public int getCount() {
        return memos.size();
    }

    @Override
    public Object getItem(int position) {
        return memos.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    public class Holder {
        TextView tv;
        TextView tv2;
        Button deleteMemoBtn;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        Holder mViewHolder = null;

        if (convertView == null) {
            mViewHolder = new Holder();

            convertView = inflater.inflate(R.layout.list_memo, parent, false);
            mViewHolder.tv = (TextView) convertView.findViewById(R.id.textView1);
            mViewHolder.tv2 = (TextView) convertView.findViewById(R.id.textView2);
            mViewHolder.deleteMemoBtn = (Button) convertView.findViewById(R.id.deleteMemoBtn);
            convertView.setTag(mViewHolder);
        } else {
            mViewHolder = (Holder) convertView.getTag();
        }

        mViewHolder.tv.setText(memos.get(position).getMemoTitle());
        mViewHolder.tv2.setText(Integer.toString(memos.get(position).getMemoID()));
        mViewHolder.tv.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(context, "You Clicked " + memos.get(position).getMemoTitle(), Toast.LENGTH_LONG).show();
            }
        });
        mViewHolder.deleteMemoBtn.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(context, "deleted " + Integer.toString(position), Toast.LENGTH_LONG).show();
                memos.remove(position);
                notifyDataSetChanged();
            }
        });


        return convertView;
    }


}