Question

美好的一天，

我正在尝试刷新我在android编程中的知识通过使用自定义适配器列表创建一个简单的备忘录应用

我的问题是，即使我打电话给＃34; NotifyDataSetChanged（）;＆＃34;，
我列表中删除的值始终是最后一个虽然当我刷新它时，它会显示正确的一个。

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;
}


}

希望有人可以帮我解释为什么这段代码无效谢谢！

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;
    }


}

Android自定义listadapter始终删除最后一项

1 个答案: