Question

我正在尝试使用自定义的ArrayAdapter从我的android活动的布局中填充GridView，其中我覆盖了getView（）。当我运行应用程序时，GridView显示在屏幕上但完全清空。我推断问题是getView（）永远不会被调用。我确实检查过ArrayList不是空的。我使用了一些日志语句（类似于System.out.print（）用于那些不熟悉Android编程的人），并发现我传递给适配器的ArrayList不是空的，但是我的适配器的getCount（）方法总是返回0.我试图通过一些android源代码来查找getView（）应该被调用，这导致getsView（）和mObjects。这一切似乎很直接，我没有发现任何错误。除非出现某种反奇迹的解释，到目前为止，我已经空了（可能是因为我是一名业余程序员）。任何帮助将不胜感激。

活动文件：

import java.util.ArrayList;

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.util.Log;
import android.view.*;
import android.widget.*;

public class LevelMapActivity extends FragmentActivity implements View.OnClickListener{

    public final int TOTAL_LEVELS = 12;//TODO Set TOTAL_LEVELS to figure out how many levels exist.
    public final int COLUMNS = 5;

    GridView grid;
LevelSelectorAdapter adapter;
ArrayList<LevelSelector> levels;

@Override
public void onCreate(Bundle savedInstanceState){

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_level_map);

    grid = (GridView)findViewById(R.id.GridView_LevelMap);
    grid.setNumColumns(COLUMNS);

    levels = new ArrayList<LevelSelector>();

    for(int i=0; i<TOTAL_LEVELS/5; i++){
        for(int j=0; j<5; j++){
            LevelSelector levelSelector = new LevelSelector(this, i*COLUMNS+j+1);
            levels.add((i*COLUMNS)+j, levelSelector);
        }
    }
    for(int j=0; j<TOTAL_LEVELS%5; j++){
        LevelSelector levelSelector = new LevelSelector(this, TOTAL_LEVELS-(COLUMNS-1)+j);
        levels.add(j+TOTAL_LEVELS-COLUMNS, levelSelector);
    }

    adapter = new LevelSelectorAdapter(this, R.layout.level_selector, levels);
    grid.setAdapter(adapter);

}//ends onCreate()

@Override
public void onPause(){

    // TODO Auto-generated method stub
    super.onPause();

}//ends onPause()

@Override
public void onClick(View view){

    // TODO Auto-generated method stub

}//ends onClick()

}//ends Class

适配器文件：

import java.util.ArrayList;

import android.content.Context;
import android.util.Log;
import android.view.*;
import android.widget.*;

public class LevelSelectorAdapter extends ArrayAdapter<LevelSelector>{

Context context;
int resource;
ArrayList<LevelSelector> levelSelectors;

public LevelSelectorAdapter(Context context, int resource, ArrayList<LevelSelector> levelSelectors){

    super(context, resource);
    this.context = context;
    this.resource = resource;
    this.levelSelectors = levelSelectors;

}//ends LevelSelectorAdapter()

public static class ViewHolder{
    public TextView level;
    public TextView time;
}

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

    View view = convertView;
    ViewHolder holder;

    if(view == null){
        LayoutInflater inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        view = inflater.inflate(resource, null);
        holder = new ViewHolder();
        holder.level = (TextView)view.findViewById(R.id.TextView_LevelSelector_Level);
        holder.time = (TextView)view.findViewById(R.id.TextView_LevelSelector_Time);
        view.setTag(holder);
    }
    else{
        holder = (ViewHolder)view.getTag();
    }

    final LevelSelector levelSelector = levelSelectors.get(position);
    if(levelSelector != null){
        holder.level.setText(Integer.toString(levelSelector.getLevel()));
        holder.time.setText(Integer.toString(levelSelector.getTime()));
    }

    return view;

}//ends getView()

}//ends Class

Answer 1

由于我尝试使用适配器尝试覆盖getView()方法的方式之一，我之前不需要在其构造函数中将数组传递给适配器。
将数组传递给超级构造函数会导致它被启动，因此可以在getCount()方法中使用。这就是getCount()每次出现0的原因，即使数组不是空的。

未调用ArrayAdapter getView（）

1 个答案: