2011-11-03 75 views
1

我遇到问题,需要为微调器选取值。这里是我的代码和适配器。Android微调器获取选定的值OnSelectedItemListener();

微调事件侦听器

category = (Spinner) findViewById(R.id.Spinner); 
category.setPrompt("Select Category.."); 
ArrayList<HashMap<String, Object>> list = new ArrayList<HashMap<String, Object>>();          
HashMap<String, Object> map = new HashMap<String, Object>(); 
map.put("Category", "Choose a Category"); 
list.add(map); 

map = new HashMap<String, Object>(); 
map.put("Icon", R.drawable.icon1); 
map.put("Category", "Category1"); 
list.add(map); 

map = new HashMap<String, Object>(); 
map.put("Icon", R.drawable.icon2); 
map.put("Category", "Category2");                  
list.add(map); 

map = new HashMap<String,Object>(); 
map.put("Icon", R.drawable.icon3); 
map.put("Category", "Category3");                    
list.add(map); 
CategoryAdapter adapter = new CategoryAdapter(v.getContext(), list,R.layout.list_layout, new String[] { "Category", "Icon" }, new int[] { R.id.category, R.id.icon }); 
category.setAdapter(adapter); 

category.setOnItemSelectedListener(new OnItemSelectedListener(){ 

@Override 
public void onItemSelected(AdapterView<?> arg0,View v, int arg2,long arg3) { 
    // TODO Auto-generated method stub 
    String selected = category.getSelectedItem().toString(); 
    //String selected = category.getTag().toString(); 
    try{ 
     //String selected = category.getSelectedItem().toString(); 
     //Object selected = arg0.getTag(); 
     //Toast.makeText(getApplicationContext(), String.valueOf(selected), Toast.LENGTH_SHORT).show(); 
     if(selected.toString().equals("Category1")){ 
      String msg1 = "Category1 type selected"; 
      Toast.makeText(getApplicationContext(), msg1 + " " + selected, Toast.LENGTH_SHORT).show(); 
     }else if(selected.toString().equals("Category2")){ 
      String msg2 = "Category2 type selected"; 
      Toast.makeText(getApplicationContext(), msg2 + " " + selected, Toast.LENGTH_SHORT).show(); 
     }else if(selected.toString().equals("Category3")){ 
      String msg3 = "Category3 type selected"; 
      Toast.makeText(getApplicationContext(), msg3 + " " + selected, Toast.LENGTH_SHORT).show(); 
     } 
    }catch(Exception e){ 
     Toast.makeText(getApplicationContext(),"Error occured " + e.getName().getClass(), Toast.LENGTH_SHORT).show(); 
    }                        
} 

@Override 
public void onNothingSelected(
     AdapterView<?> arg0) { 
    // TODO Auto-generated method stub 
    Toast.makeText(getApplicationContext(), "nothing selected", Toast.LENGTH_SHORT).show(); 
} 

}); 

CategoryAdapter

public class ReminderCategoryAdapter extends SimpleAdapter{ 

    Context c; 

    public ReminderCategoryAdapter(Context context, List<? extends Map<String, ?>> data, 
      int resource, String[] from, int[] to) { 
     super(context, data, resource, from, to); 
     c = context; 

    } 

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

     if (convertView == null) { 
      LayoutInflater li = (LayoutInflater) c.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
      convertView = li.inflate(R.layout.list_layout,null); 
     } 

     HashMap<String, Object> data = (HashMap<String, Object>) getItem(position); 

     ((TextView) convertView.findViewById(R.id.category)).setText((String) data.get("Category")); 
     ((TextView) convertView.findViewById(R.id.category)).setTag((Object) data.get("Category")); 

     return convertView; 
    } 
} 

我的微调,在适配器,我吹图片+文字,我的微调工作发现,特此我说明我的微调

============================

| Icon1 Text1 |

| Icon2 Text2 |

| Icon3 Text3 |

但是,一旦我尝试使用onitemselectedlistener并使用getSelectedItem()。toString()方法并对其进行烘烤,则敬酒时的值返回值就是图标和文本的组合,我不希望图标的值将会返回,但我只想要字符串或文本。我尝试使用setTag(Object value)方法使用((TextView)convertView.findViewById(R.id.category))。setTag((Object)data.get(“Category”));在适配器中,并且在侦听器中使用getTag()方法时,抛出nullpointer异常。除了使用getItemPosition(position)或getSelectedItem()方法之外,还有其他解决方案来获取和操作所选项目的字符串值吗? 请帮忙。

回答

2

您可以轻松使用的一种解决方案是使用Spinner#getSelectedItemPosition()方法。此方法将返回选定项目的位置,并且您可以从传递给适配器的列表中检索项目本身。

所以基本上,替换下面的行中的onItemSelected方法:

String selected = category.getSelectedItem().toString(); 

有:

String selected = list.get(category.getSelectedItemItemPosition()).get("Category"); 
+1

只是为了解释这个有点多,'category.getSelectedItem()'返回一个Map实例。这就是为什么'toString()'不起作用。如果你做'category.getSelectedItem()。get(“Category”)'',你将在地图中获得该键的值。 – dmon

+0

谢谢,我的问题解决了。 – Zahary