Android：如何重複使用具有動態數量項目和多個佈局的列表視圖項目

Question

當我嘗試在具有多個自定義佈局的ListView中重用視圖時，會出現問題。當我更改數量的項目時，我得到錯誤convertView被傳遞給getView方法。詳細信息： 我有一個頁眉佈局，行佈局和頁腳佈局。在標題中，我可以更改行數。 1行的示例： 標頭 row1 頁腳 當我重新使用視圖時，我得到錯誤的結果（添加另一行後）。這是因爲先前創建頁腳視圖傳遞的位置= 2，因爲它不爲空，我不重建它： 頭 ROW1 頁腳 頁腳

相反的預期： 頭 ROW1 2行 頁腳

我在做什麼錯？或者是設計，我應該重新創建視圖而不是重複使用它們？ 這裏去我的代碼：

public class NewProgramAdapter extends BBBaseAdapter { 

public static int TYPE_HEADER = 1; 
public static int TYPE_FORM = 2; 
public static int TYPE_FOOTER = 3; 

protected String mDays; 
protected String mProgramId; 
protected int currentDay = 0; 
protected int numberOfExercises = 1; 
protected JSONArray items = new JSONArray(); 

public NewProgramAdapter(Activity a) { 
    super(a); 
    // TODO Auto-generated constructor stub 
} 

@Override 
public int getCount() { 
    return numberOfExercises + 2; // header and footer 
} 

@Override 
public Object getItem(int position) { 
    return position; 
} 

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

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

    if (position > 0 && position < getCount() - 1) { 
     return getFormView(position, convertView, parent); 
    } else if (position == 0) { 
     return getHeaderView(position, convertView, parent); 
    } else { 
     return getFooterView(position, convertView, parent); 
    } 
} 

private View getFooterView(int position, View convertView, ViewGroup parent) { 
    View v = convertView; 
    if (v == null) { 
     LayoutInflater inflater = mA.getLayoutInflater(); 
     v = inflater.inflate(R.layout.new_exercise_footer, null); 
    } 
    return v; 
} 

private View getHeaderView(int position, View convertView, ViewGroup parent) { 
    View v = convertView; 
    if (v == null) { 
     LayoutInflater inflater = mA.getLayoutInflater(); 
     v = inflater.inflate(R.layout.new_exercise_header, null); 
     Spinner sp = (Spinner) v.findViewById(R.id.spinnerExercises); 
     sp.setOnItemSelectedListener(new OnItemSelectedListener() { 
      @Override 
      public void onItemSelected(AdapterView<?> parentView, 
        View selectedItemView, int position, long id) { 
       int n = position + 1; 
       setNumberOfExercises(n); 
      } 

      @Override 
      public void onNothingSelected(AdapterView<?> parentView) { 
       // your code here 
      } 

     }); 
    } 
    return v; 
} 

private View getFormView(int position, View convertView, ViewGroup parent) { 

    View v = convertView; 
    if (v == null) { 
     LayoutInflater inflater = mA.getLayoutInflater(); 
     v = inflater.inflate(R.layout.new_exercise_form, null); 
    } 
    return v; 
} 

@Override 
public int getItemViewType(int position) { 
    if (position > 0 && position < getCount() - 1) { 
     return TYPE_FORM; 
    } else if (position == 0) { 
     return TYPE_HEADER; 
    } else { 
     return TYPE_FOOTER; 
    } 
} 

@Override 
public void updateEntries(Object data) { 
    items = (JSONArray) data; 
    notifyDataSetChanged(); 
} 

public void next() { 
    currentDay++; 
    notifyDataSetChanged(); 
} 

public void setNumberOfExercises(int n) { 
    numberOfExercises = n; 
    notifyDataSetChanged(); 
} 

public void setDays(String string) { 
    mDays = string; 
} 

public void setProgramId(String string) { 
    mProgramId = string; 
} 

}

Answer 1

看起來你忘了覆蓋getViewTypeCount()告訴使用多行佈局適配器。

但是，如果您只需要頁眉，頁腳和行佈局，那麼您應該使用ListView#addHeaderView()和ListView#addFooterView()。不要試圖控制頁眉和頁腳是你的適配器，ListView已經爲你做了。