0

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，这是应用程序屏幕的链接：

图片

通过更改列表行左侧的图像来更改颜色。现在，当我在列表中向下滑动更改颜色时，颜色又回到原来的状态（意味着图像视图恢复到其原始来源）。

列表的数据取自 XML 文件，解析为散列映射，并使用扩展到列表中的适配器。我该如何解决这个问题？

正如我所看到的，因为列表视图重用了不在屏幕上的视图，所以当我回到屏幕外的已更改行然后又回来时，它会再次从哈希映射中提取其信息。所以我需要做的是在哈希映射中找到由适配器绑定到行布局的数据索引，并在那里更改关联的颜色，这样下次适配器重新创建该行时，它将被分配用正确的颜色。如何才能做到这一点？

这是此活动的 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;
}}
4

1 回答 1

0

您应该重新使用已经创建的视图。像这样的事情：

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;
}
于 2013-01-18T01:38:15.247 回答