android - ListView 行中的 TextView 在 Android 滚动时显示重复值？

Question

我正在使用 ListView 的自定义适配器，其中有一个 TextView 和一个 Spinner。从微调器中选择值后，将值复制到相应列表的同一行的 TextView 中。

问题是，由于我在 ListView 中有超过 40 个元素，当我选择第一个微调器并将值设置为相应的 TextView 时，在滚动时，在第 10 行 TextView 中看到相同的值。

滚动时，值从第 1 个 TextView 复制到第 10 个 TextView。

下面是我使用的代码:

public class AppListAdapter extends BaseAdapter {

    private LayoutInflater mInflater;
    private List<App> mApps = Constants.list;
    private Context _activity;
    ArrayList<String> months=null;
    ArrayAdapter<String> dataAdapter =null;
    int spinerposition;
    int viewposition;

    int temp=0;
    private int screenWidth;


    /**
     * Constructor.
     * 
     * @param context the application context which is needed for the layout inflater
     * @param screenWidth 
     */
    public AppListAdapter(Context context, int screenWidth) {
        // Cache the LayoutInflate to avoid asking for a new one each time.
        mInflater = LayoutInflater.from(context);
        this._activity=context;
        this.screenWidth = screenWidth;

        months = new ArrayList<String>();
        months.add("No Item Selected");
        months.add("None");
        months.add("Entertainment");
        months.add("Games");
        months.add("News/Books");
        months.add("Social Networking");
        months.add("Utilities");
        months.add("Texting");
        months.add("Web Browsers");


        // Creating adapter for spinner
        dataAdapter = new ArrayAdapter<String>(_activity,
                android.R.layout.simple_spinner_item, months);

        // Drop down layout style - list view with radio button
        dataAdapter.setDropDownViewResource(android.R.layout.select_dialog_singlechoice);


    }

    public int getCount() {

        return mApps.size();
    }

    public Object getItem(int position) {
        return mApps.get(position);
    }

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

    public View getView(final int position, View convertView, ViewGroup parent) {

        final AppViewHolder holder;

        viewposition=position;
        if(convertView == null) {
            convertView = mInflater.inflate(R.layout.row, null);
            // creates a ViewHolder and stores a reference to the children view we want to bind data to
            holder = new AppViewHolder();

            holder.spiner=(Spinner)convertView.findViewById(R.id.spinner);
            holder.offtext=(TextView)convertView.findViewById(R.id.off_txt);


            holder.offTxt = (TextView) convertView.findViewById(R.id.off_txt);
            holder.apptitleTxt = (TextView) convertView.findViewById(R.id.apptitle_txt);
            Typeface typeface = Typeface.createFromAsset(_activity.getAssets(),"CHICM___.TTF");
            holder.apptitleTxt.setTypeface(typeface);
            holder.offTxt.setTypeface(typeface);

            if(screenWidth>480){
                holder.offTxt.setTextSize(30);
                holder.apptitleTxt.setTextSize(30);
            }
            convertView.setTag(holder);
        } else { 
            holder = (AppViewHolder) convertView.getTag();
        }

        holder.setTitle(mApps.get(position).getTitle(),mApps.get(position).getVersionName());

        notifyDataSetChanged();

        holder.offTxt.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                holder.spiner.performClick();

            }
        });

        holder.spiner.setAdapter(dataAdapter);
        holder.spiner.setOnItemSelectedListener(new OnItemSelectedListener() {
            public void onItemSelected(AdapterView<?> arg0, View arg1,int arg2, long arg3) {
                spinerposition=arg2;
                switch (spinerposition)
                {
                case 1:

                    holder.offtext.setText("None");
                    break;
                case 2:

                    holder.offtext.setText("Entertainment");
                    break;
                case 3:

                    holder.offtext.setText("Games");
                    break;
                case 4:

                    holder.offtext.setText("News/Books");
                    break;
                case 5:

                    holder.offtext.setText("Social Networking");
                    break;
                case 6:

                    holder.offtext.setText("Utilities");
                    break;
                case 7:

                    holder.offtext.setText("Texting");
                    break;
                case 8:

                    holder.offtext.setText("Web Browsers");
                    break;
                }
            }
            public void onNothingSelected(AdapterView<?> arg0) {
            }
        });
        return convertView; 
    }



    /**
     * Sets the list of apps to be displayed.
     * 
     * @param list the list of apps to be displayed
     */
    public void setListItems(List<App> list) { 
        mApps = list; 
    }

    /**
     * A view holder which is used to re/use views inside a list.
     */
    public class AppViewHolder {

        private TextView mTitle = null;
        private TextView apptitleTxt = null;
        private TextView offTxt = null;
        private Spinner spiner=null;
        public TextView offtext;
        /**
         * Sets the text to be shown as the app's title
         * 
         * @param title the text to be shown inside the list row
         */
        public void setTitle(String title,String category) {
            apptitleTxt.setText(title);
//          offtext.setText(category);
        }
    }

}

Answer 1

这是因为 ListView 正在重用所有以前的滚动(不可见)的 Views。

请查看this主题。