如何在Listview行中保存已更改的ImageView状态，之后它从屏幕上消失了？

Question

我设计了一个带有列表视图的应用程序，我可以在其中更改列表项的颜色，这里是应用程序屏幕的链接：

通过更改列表行左侧的图像来更改颜色。现在，当我在列表中更改颜色向下滑动时，颜色返回到原始状态（意味着图像视图返回其原始源）。

列表的数据取自XML文件，解析为哈希映射，并使用扩展到列表中的适配器。我怎样才能解决这个问题？

正如我所看到的那样，因为list-view重用了不在屏幕上的视图，当我回到屏幕上的更改行然后返回时，它会再次从哈希映射中提取其信息。所以我需要做的是找到哈希映射中的数据索引，该索引由适配器绑定到行布局，并在那里更改关联的颜色，这样下次适配器重新创建此行时，它将被分配用正确的颜色。怎么办呢？

以下是此活动的Java代码：

public class SkyGiraffeAppActivity extends Activity implements AdapterView.OnItemClickListener, View.OnClickListener {
// All static variables
static final String TAG = "SkyGiraffeAppActivity";
// XML node keys
static final String KEY_TASK = "task"; // parent node
static final String KEY_ID = "id";
static final String KEY_TITLE = "title";
static final String KEY_DATE = "date";
static final String KEY_TIME = "time";
static final String KEY_PRIORITY  = "priority";
static final String KEY_USERPRIORITY = "userpriority";

View currentRow;
final ArrayList<HashMap<String, String>> menuItems = new ArrayList<HashMap<String, String>>();

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
    ListView list = new ListView(this);
    list.setDivider(null);
    list.setDividerHeight(0);

    setContentView(list);
    getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE, R.layout.taskstitle);


    Log.e(TAG, "Created Array");

    XMLParser parser = new XMLParser();

    Log.e(TAG, "Getting xml from raw folder");
    InputStream xml = getResources().openRawResource(R.raw.taskslists); // getting XML

    Log.e(TAG, "reading xml file to string");
    String sxml = parser.readTextFile(xml);

    Log.e(TAG, "creating dom element from string");
    Document doc = parser.getDomElement(sxml); // getting DOM element

    Log.e(TAG, "getting node list of all the elements");
    NodeList nodeList = doc.getElementsByTagName(KEY_TASK);

    Log.e(TAG, "looping through all the elements");
    for (int i = 0; i < nodeList.getLength(); i++) 
    {
        // creating new HashMap
        HashMap<String, String> map = new HashMap<String, String>();
        Element e = (Element) nodeList.item(i);
        Log.e(TAG, "element number: " + i + " added to hash map");
        // adding each child node to HashMap key => value
        map.put(KEY_ID, parser.getValue(e, KEY_ID));
        map.put(KEY_TITLE, parser.getValue(e, KEY_TITLE));
        map.put(KEY_DATE, parser.getValue(e, KEY_DATE));
        map.put(KEY_TIME, parser.getValue(e, KEY_TIME));
        map.put(KEY_PRIORITY, parser.getValue(e, KEY_PRIORITY));
        map.put(KEY_USERPRIORITY, parser.getValue(e, KEY_USERPRIORITY));

        // adding HashList to ArrayList
        menuItems.add(map);
    }

    // Adding menuItems to ListView
    ListAdapter adapter = new SimpleAdapter(this, menuItems, R.layout.row,
          new String[] { KEY_TITLE, KEY_DATE, KEY_TIME, KEY_PRIORITY, KEY_USERPRIORITY}, 
          new int[]    { R.id.text_title, R.id.text_date, R.id.text_time ,R.id.image_priority, R.id.bchangecolor}){

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            View row =  super.getView(position, convertView, parent);
            View left = row.findViewById(R.id.bchangecolor);
            left.setTag(position);
            left.setOnClickListener(SkyGiraffeAppActivity.this);
            View right = row.findViewById(R.id.barrow);
            right.setTag(position);
            right.setOnClickListener(SkyGiraffeAppActivity.this);


            ImageView prioriy = (ImageView) row.findViewById(R.id.image_priority);
            ImageView usercolor = (ImageView) row.findViewById(R.id.bchangecolor);


            String userpriority = menuItems.get(position).get(KEY_USERPRIORITY);   
            Log.e(TAG, "user priority color for this view was: " + userpriority);

            if (userpriority.contentEquals("green"))
            {
                usercolor.setImageResource(R.drawable.task_bg_left_green);
            }
            else if (userpriority.contentEquals("blue"))
            {
                usercolor.setImageResource(R.drawable.task_bg_left_blue);
            }
            else if (userpriority.contentEquals("yellow"))
            {
                usercolor.setImageResource(R.drawable.task_bg_left_yellow);
            }
            else if (userpriority.contentEquals("orange"))
            {
                usercolor.setImageResource(R.drawable.task_bg_left_orange);
            }
            else if (userpriority.contentEquals("red"))
            {
                usercolor.setImageResource(R.drawable.task_bg_left_red);
            }


            int number = Integer.valueOf(menuItems.get(position).get(KEY_PRIORITY));
            switch ( number )
            {
            case 1:
                prioriy.setImageResource(R.drawable.priority_first);
                break;
            case 2:
                prioriy.setImageResource(R.drawable.priority_second);
                break;
            case 3:
                prioriy.setImageResource(R.drawable.priority_third);
                break;
            case 4:
                prioriy.setImageResource(R.drawable.priority_fourth);
                break;
            case 5:
                prioriy.setImageResource(R.drawable.priority_fifth);
                break;
            default:
                prioriy.setImageResource(R.drawable.priority_first);
            }

            return row;
        }
    };

    list.setAdapter(adapter);
    list.setOnItemClickListener(this);  
}

public void onClick(View v) 
{
     Intent i = new Intent(this, TaskColorChangeActivity.class);
     i.putExtra("color", "choosecolor");

     switch(v.getId()) {
        case R.id.bchangecolor:
            Log.e(TAG, "pressed the color change button on" + v.getId());
            currentRow = v;
            startActivityForResult(i, 1);
            break;
        case R.id.barrow:
            Log.e(TAG, "pressed the arrow button on" + v.getId());
            i = createIntentwithExtra(v.getRootView());
            startActivity(i);
            break;
        default:
            break;
        }   
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    // TODO Auto-generated method stub
    super.onActivityResult(requestCode, resultCode, data);

    if(data.getExtras().containsKey("chosencolor"))
    {
        ImageView imageView = (ImageView) currentRow.findViewById(R.id.bchangecolor);
        if (data.getStringExtra("chosencolor").contentEquals("blue"))
        {
            imageView.setImageResource(R.drawable.task_bg_left_blue);
            //menuItems.get(po)
        }
        else if (data.getStringExtra("chosencolor").contentEquals("green"))
        {
            imageView.setImageResource(R.drawable.task_bg_left_green);
        }
        else if (data.getStringExtra("chosencolor").contentEquals("yellow"))
        {
            imageView.setImageResource(R.drawable.task_bg_left_yellow);
        }
        else if (data.getStringExtra("chosencolor").contentEquals("orange"))
        {
            imageView.setImageResource(R.drawable.task_bg_left_orange);
        }
        else if (data.getStringExtra("chosencolor").contentEquals("red"))
        {
            imageView.setImageResource(R.drawable.task_bg_left_red);    
        } 
    }
}

public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
    Log.e(TAG, "pressed the row itself" + v.getId());
    Intent intent = createIntentwithExtra(v);
    startActivity(intent);  
}

public Intent createIntentwithExtra(View v)
{
    Intent intent = new Intent(getApplicationContext(), SingleMenuItemActivity.class);
    String title = ((TextView) v.findViewById(R.id.text_title)).getText().toString();
    String date = ((TextView) v.findViewById(R.id.text_date)).getText().toString();
    String time = ((TextView) v.findViewById(R.id.text_time)).getText().toString();
    intent.putExtra(KEY_TITLE, title);
    intent.putExtra(KEY_DATE, date);
    intent.putExtra(KEY_TIME, time);

    return intent;
}}

Answer 1

你应该重新使用已经创建的视图。这样的事情：

public View getView(int position, View convertView, ViewGroup parent) {
    ViewHolder holder = null;
    if(convertView == null){
        //CREATE NEW HOLDER
        holder = new ViewHolder();
        // Layout XML
        int layoutFile = R.layout.adapter_layout;
        LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        convertView = inflater.inflate(layoutFile, null);
        convertView.setTag(holder);
        holder.tvName= (TextView)convertView.findViewById(R.id.tvName);

              /// SET DE VALUES TO THE VIEW HERE, INCLUDING THE
              /// ONCLICK TO THE VIEW
    Users u = arrayUser.get(position);

    holder.tvName.setText(u.getName());


    }
    else
        holder= (ViewHolder)convertView.getTag();
    return convertView;
}

static class ViewHolder{
    TextView tvName;
}