如何显示只在某些行

Question

我有一个自定义适配器的ListView图像按钮。我想根据列表中的条件在每行上设置ImageButton的可见性。但是，这些行并不包含我所设想的内容。

在下面我的例子中有一个财产count称为ColorInfo类。每当计数大于0时，我想显示图像。为伪数据我已经与每个具有偶数项目计数填充在阵列的ColorInfo 20个元素大于0。然而，当我运行我没有看到在交替行中的ImageButton该应用

下面是一个完整的例子：

DemoActivity

public class DemoActivity extends Activity { 
    @Override 
    public void onCreate(Bundle savedInstanceState) 
    { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 

     ColorInfo[] clr= new ColorInfo[20]; 

     for(int i=0;i<20;i++){ 
      ColorInfo clrInfo = new ColorInfo(); 
      if (i%2 == 0) { 
       clrInfo.count = 5; 
      } 
      clr[i] = clrInfo; 
     } 
     ((ListView)findViewById(R.id.list)).setAdapter(new MyAdapter(this, 0, clr)); 
    } 

    private class MyAdapter extends ArrayAdapter<ColorInfo> { 
     ViewHolder holder; 
     LayoutInflater inflater; 
     public MyAdapter(Context context, int textViewResourceId,ColorInfo[] objects) { 
      super(context, textViewResourceId, objects); 
      inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
     } 
     @Override 
     public View getView(int position, View convertView, ViewGroup parent) { 
      View itemView = convertView; 

      final ColorInfo item = getItem(position); 

      if(itemView == null){ 
       itemView = inflater.inflate(R.layout.row, null); 
       holder = new ViewHolder(); 
       holder.editButton = (ImageButton) itemView.findViewById(R.id.some_button); 
       itemView.setTag(holder); 
      } 
      else 
       holder = (ViewHolder)itemView.getTag(); 

      if (item.count>0) 
       holder.editButton.setVisibility(View.VISIBLE); 

      return itemView; 
     } 
     private class ViewHolder{ 
      ImageButton editButton; 
     } 
    } 
    private static class ColorInfo{ 
     int count = 0; 
    } 
} 

main.xml中

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent" 
    android:orientation="vertical" > 

    <ListView 
     android:id="@+id/list" 
     android:layout_width="fill_parent" 
     android:layout_height="wrap_content" > 
    </ListView> 

</LinearLayout> 

row.xml

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    android:layout_width="match_parent" 
    android:layout_height="match_parent" 
    android:orientation="vertical" > 

    <TextView 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:text="test"/> 

    <ImageButton 
     android:id="@+id/some_button" 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:background="#000000" 
     android:visibility="gone" 
     android:src="@drawable/ic_some_img"/> 
</LinearLayout> 

更新

我找到了答案here显然因为行是通过重复使用ArrayAdapter其良好的有一个else条件为好。

Answer 1

以下是我正在做它来设置图像仅在特定位置：

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

        View vi = convertView; 

        if (vi == null) 
         vi = inflater.inflate(R.layout.row, null); 

ImageView iv = (ImageView)vi.findViewById(R.id.someImageButton); 

        if (position == 0) { 



         iv.setVisibility(View.VISIBLE); 

        } 
        if (position == 1) { 

         //Something 

        } 
        if (position == 2) { 

         //Something 

        } 
        if (position == 3) { 



         iv.setVisibility(View.VISIBLE); 

        } 

        return vi; 
       } 
      } 

也许这是你在找什么。