gridview的item高度不同产生重叠，怎么解决

GridView中item高度自适应

 public class MyAdapter extends BaseAdapter {

    GridView mGv;   
  public static int ROW_NUMBER = 5;

  public MyAdapter (GridView gv, Context mContext, ArrayList<String> list) {
    this.context = mContext;
    this.mGv = gv;
    lstDate = list;
  }

     @Override
  public View getView(int position, View convertView, ViewGroup parent) {
    convertView = LayoutInflater.from(context).inflate(R.layout.item, null);
    //高度计算
    AbsListView.LayoutParams param = new AbsListView.LayoutParams(
        android.view.ViewGroup.LayoutParams.FILL_PARENT,
        mGv.getHeight()/ROW_NUMBER);
    convertView.setLayoutParams(param);

    return convertView;
  }