我在Android Boot Camp for Developers第2版的第7章中进行了练习。本书针对ICS,但我试图不使用已弃用的图库小部件,而是使用 HorizontalScrollView 。
现在 setAdapter 尚未被识别,在代码中我还有一个问题, arg0 和 arg2 也未被识别。我可以通过将对 HorizontalScrollView 的调用还原为图库来解决 setAdapter 问题,但 arg 问题仍然存在。下面是小类文件的完整代码。
谢谢!
import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.HorizontalScrollView;
import android.widget.ImageView;
import android.widget.Toast;
public class MainActivity extends Activity {
public Integer[] Animals = {R.drawable.elephant, R.drawable.gorilla, R.drawable.leopard, R.drawable.monkey, R.drawable.panda, R.drawable.redpanda};
ImageView imageView;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
HorizontalScrollView ga = (HorizontalScrollView) findViewById(R.id.horizontalScrollView);
imageView = (ImageView) findViewById(R.id.imgAnimal);
ga.setAdapter(new ImageAdapter(this));
ga.setOnClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Toast.makeText(getBaseContext(), "You have selected picture " + (arg2 + 1)
+ " of the endangered species", Toast.LENGTH_SHORT).show();
imageView.setImageResource(Animals[arg2]);
}
});
}
public class ImageAdapter extends BaseAdapter {
private Context context;
public ImageAdapter(Context c) {
context = c;
}
@Override
public int getCount() {
return Animals.length;
}
@Override
public Object getItem(int position) {
return null;
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
ImageView pic = new ImageView(context);
pic.setImageResource(Animals[arg0]);
pic.setScaleType(ImageView.ScaleType.FIT_XY);
pic.setLayoutParams(new HorizontalScrollView.LayoutParams(200, 175));
return pic;
}
}
}
答案 0 :(得分:0)
将这两个变量替换为position
答案 1 :(得分:0)
您需要使用LinearLayout
包含HorizontalScrollView
或类似内容,与使用常规ScrollView
完全相同。其他(更好)选项是使用RecyclerView
和LinearLayoutManager
,将其调整为水平滚动。像这样:
mRecyclerView.setLayoutManager(new LinearLayoutManager(context, LinearLayoutManager.HORIZONTAL, false));
在这种情况下,您需要使适配器扩展RecyclerView.Adapter
。