BaseAdapter优化问题

[xiong1250]

学了BaseAdapter优化问题，感觉还能优化一点，就自己写个方法想实验下，图片总是不能加载完全只有一张，有人帮我看看或者跟我说说conertView底层到底怎么回事，怎么就替代不了呢

public class baseAdapterActivity1 extends Activity{
	LayoutInflater li;
	ViewHolder vh=new ViewHolder();
	ListView lv;
	int []pp={R.drawable.b,R.drawable.bg4,R.drawable.m,R.drawable.m2,R.drawable.m3,R.drawable.m8,R.drawable.p,R.drawable.psb};
@Override
protected void onCreate(Bundle savedInstanceState) {
	// TODO Auto-generated method stub
	super.onCreate(savedInstanceState);
	setContentView(R.layout.baselist);
	lv=(ListView) findViewById(R.id.b_lv);
	li=getLayoutInflater();
	vh.cont=li.inflate(R.layout.b_item, null);
	vh.tv=(TextView) vh.cont.findViewById(R.id.b_tv);
	vh.iv=(ImageView) vh.cont.findViewById(R.id.b_iv);
	lv.setAdapter(new BaseAdapter() {
		
		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			// TODO Auto-generated method stub
			View v=vh.cont;
			vh.tv.setText("图片"+(position+1));
			vh.iv.setImageResource(pp[position]);
			System.out.println(position);
			return v;
		}
		
		@Override
		public long getItemId(int position) {
			// TODO Auto-generated method stub
			return position;
		}
		
		@Override
		public Object getItem(int position) {
			// TODO Auto-generated method stub
			return null;
		}
		
		@Override
		public int getCount() {
			// TODO Auto-generated method stub
			return pp.length;
		}
	});
	lv.setOnItemClickListener(new OnItemClickListener() {

		@Override
		public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
				long arg3) {
			// TODO Auto-generated method stub
			Intent in=new Intent("look");
			in.putExtra("pp", pp);
			in.putExtra("p", arg2);
			startActivity(in);
		}
	});
	
}
 	static class ViewHolder{
 		View cont;
 		TextView tv;
 		ImageView iv;
 	}
}

[xiong1250]

BaseAdapter原型：

lv=(ListView) findViewById(R.id.b_lv);
	li=getLayoutInflater();

	//vh.tv=(TextView) vh.cont.findViewById(R.id.b_tv);
	//vh.iv=(ImageView) vh.cont.findViewById(R.id.b_iv);
	lv.setAdapter(new BaseAdapter() {
		
		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			// TODO Auto-generated method stub
			View v=convertView;
			if(v==null){
				v=li.inflate(R.layout.b_item, null);
				vh.tv=(TextView) v.findViewById(R.id.b_tv);
				vh.iv=(ImageView) v.findViewById(R.id.b_iv);
				v.setTag(vh);
			}
			else
				vh=(ViewHolder) v.getTag();
			vh.tv.setText("图片"+(position+1));
			vh.iv.setImageResource(pp[position]);
			System.out.println(position);
			return v;
		}

[酒比花香]

我理解的 View convertView 指的是listview里面的每一行view，是定义好的。你需要做的是在convertview基础上进行修改，而不是将他替换掉。 if (convertView == null) { convertView = li.inflate(R.layout.b_item, null); vh.tv=(TextView) v.findViewById(R.id.b_tv); vh = new ViewHolder(); vh.tv=(TextView) v.findViewById(R.id.b_tv); vh.iv=(ImageView) v.findViewById(R.id.b_iv); convertView.setTag(holder); convertView.setTag(holder); } else { vh = (ViewHolder) convertView.getTag(); } vh.tv.setText("图片"+(position+1)); vh.iv.setImageResource(pp[position]); return convertView; } // 单独的类ViewHolder private class ViewHolder { private TextView tv; private ImageView iv; }

[xiong1250]

没人能给解决下吗

[xiong1250]

引用 3 楼 leehu1987 的回复:

我理解的 View convertView 指的是listview里面的每一行view，是定义好的。你需要做的是在convertview基础上进行修改，而不是将他替换掉。 if (convertView == null) { convertView = li.inflate(R.layout.b_item, null); vh.tv=(TextView) v.findViewById(R.id.b_tv); vh = new ViewHolder(); vh.tv=(TextView) v.findViewById(R.id.b_tv); vh.iv=(ImageView) v.findViewById(R.id.b_iv); convertView.setTag(holder); convertView.setTag(holder); } else { vh = (ViewHolder) convertView.getTag(); } vh.tv.setText("图片"+(position+1)); vh.iv.setImageResource(pp[position]); return convertView; } // 单独的类ViewHolder private class ViewHolder { private TextView tv; private ImageView iv; }

我也明白它是定义好的，我就想看看它究竟的原理，是不是一个简单的上次用过View,而且替换后可以一次定义多次使用，发现我想多了。。谢谢的你回答