Question

我正在尝试构建和运行应用程序，并在菜单列表适配器类上收到错误消息：

View Holder中的View Holder（）不能为空。

这是我要使用Android Studio构建应用程序的Android代码

import android.annotation.SuppressLint;
import android.app.Activity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.FrameLayout;
import android.widget.TextView;
import java.util.ArrayList;
import com.weather.queensland.weather.pojo.MenuListPojo;

public class MenuListAdapter extends ArrayAdapter<MenuListPojo>
{
  Activity activity;
  private ArrayList<MenuListPojo> dataSet;
  private int lastPosition = -1;

  @SuppressLint("ResourceType")
  public MenuListAdapter(ArrayList<MenuListPojo> paramArrayList, Activity paramActivity)
  {
    super(paramActivity, 2131296289, paramArrayList);
    this.dataSet = paramArrayList;
    this.activity = paramActivity;
  }

  @SuppressLint("ResourceType")
  public View getView(int paramInt, View paramView, ViewGroup paramViewGroup)
  {
    MenuListPojo localMenuListPojo = (MenuListPojo)getItem(paramInt);
    ViewHolder localViewHolder;
    if (paramView == null)
    {
      localViewHolder = new ViewHolder(null);
      paramView = LayoutInflater.from(getContext()).inflate(2131296289, paramViewGroup, false);
      localViewHolder.nav_new_title = ((TextView)paramView.findViewById(2131165332));
      localViewHolder.nav_new = ((FrameLayout)paramView.findViewById(2131165321));
      paramView.setTag(localViewHolder);
    }
    for (paramViewGroup = localViewHolder;; paramViewGroup = (ViewHolder)paramView.getTag())
    {
      this.lastPosition = paramInt;
      paramViewGroup.nav_new_title.setText(localMenuListPojo.getTitle());
      paramViewGroup.nav_new.setOnClickListener(new View.OnClickListener()
      {
        public void onClick(View paramAnonymousView)
        {
          int i = ((Integer)paramAnonymousView.getTag()).intValue();
          paramAnonymousView = (MenuListPojo)MenuListAdapter.this.getItem(i);
          ((ForecastWeatherActivity)MenuListAdapter.this.activity).callOnMenuItemSelection(paramAnonymousView.getLink());
        }
      });
      paramViewGroup.nav_new.setTag(Integer.valueOf(paramInt));
      return paramView;
    }
  }

  private static class ViewHolder
  {
    FrameLayout nav_new;
    TextView nav_new_title;
  }
}

Answer 1

在您的getView()函数中，您的视图持有者默认构造函数应类似于

localViewHolder = new ViewHolder();

不是这个

localViewHolder = new ViewHolder(null);

将其设置为parameterized constructor，而您将其作为参数值null

传递

错误消息是View Holder不能为Null

1 个答案: