listView中多個listItem布局時，convertView緩存及使用

package com.bestv.listViewTest;

import java.util.ArrayList;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.CheckBox;
import android.widget.ImageView;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;

public class listViewTest extends Activity {
/** Called when the activity is first created. */
ListView listView;
MyAdapter listAdapter;
ArrayList<String> listString;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
listView = (ListView)this.findViewById(R.id.listview);
listString = new ArrayList<String>();
for(int i = 0 ; i < 100 ; i++)
{
listString.add(Integer.toString(i));
}
listAdapter = new MyAdapter(this);
listView.setAdapter(listAdapter);
}

class MyAdapter extends BaseAdapter{

Context mContext;
LinearLayout linearLayout = null;
LayoutInflater inflater;
TextView tex;
final int VIEW_TYPE = 3;
final int TYPE_1 = 0;
final int TYPE_2 = 1;
final int TYPE_3 = 2;

public MyAdapter(Context context) {
// TODO Auto-generated constructor stub
mContext = context;
inflater = LayoutInflater.from(mContext);
}

@Override
public int getCount() {
// TODO Auto-generated method stub
return listString.size();
}

//每個convert view都會調用此方法，獲得當前所需要的view樣式
@Override
public int getItemViewType(int position) {
// TODO Auto-generated method stub
int p = position%6;
if(p == 0)
return TYPE_1;
else if(p < 3)
return TYPE_2;
else if(p < 6)
return TYPE_3;
else
return TYPE_1;

}

@Override
public int getViewTypeCount() {
// TODO Auto-generated method stub
return 3;
}

@Override
public Object getItem(int arg0) {
// TODO Auto-generated method stub
return listString.get(arg0);
}

@Override
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
viewHolder1 holder1 = null;
viewHolder2 holder2 = null;
viewHolder3 holder3 = null;
int type = getItemViewType(position);


//無convertView，需要new出各個控件
if(convertView == null)
{ 
Log.e("convertView = ", " NULL");

//按當前所需的樣式，確定new的布局
switch(type)
{
case TYPE_1:
convertView = inflater.inflate(R.layout.listitem1, parent, false);
holder1 = new viewHolder1();
holder1.textView = (TextView)convertView.findViewById(R.id.textview1);
holder1.checkBox = (CheckBox)convertView.findViewById(R.id.checkbox);
Log.e("convertView = ", "NULL TYPE_1");
convertView.setTag(holder1);
break;
case TYPE_2:
convertView = inflater.inflate(R.layout.listitem2, parent, false);
holder2 = new viewHolder2();
holder2.textView = (TextView)convertView.findViewById(R.id.textview2);
Log.e("convertView = ", "NULL TYPE_2");
convertView.setTag(holder2);
break;
case TYPE_3:
convertView = inflater.inflate(R.layout.listitem3, parent, false);
holder3 = new viewHolder3();
holder3.textView = (TextView)convertView.findViewById(R.id.textview3);
holder3.imageView = (ImageView)convertView.findViewById(R.id.imageview);
Log.e("convertView = ", "NULL TYPE_3");
convertView.setTag(holder3);
break;
}
}
else
{
//有convertView，按樣式，取得不用的布局
switch(type)
{
case TYPE_1:
holder1 = (viewHolder1) convertView.getTag();
Log.e("convertView !!!!!!= ", "NULL TYPE_1");
break;
case TYPE_2:
holder2 = (viewHolder2) convertView.getTag();
Log.e("convertView !!!!!!= ", "NULL TYPE_2");
break;
case TYPE_3:
holder3 = (viewHolder3) convertView.getTag();
Log.e("convertView !!!!!!= ", "NULL TYPE_3");
break;
}
}

//設置資源
switch(type)
{
case TYPE_1:
holder1.textView.setText(Integer.toString(position));
holder1.checkBox.setChecked(true);
break;
case TYPE_2:
holder2.textView.setText(Integer.toString(position));
break;
case TYPE_3:
holder3.textView.setText(Integer.toString(position));
holder3.imageView.setBackgroundResource(R.drawable.icon);
break;
}


return convertView;
}

}


//各個布局的控件資源

class viewHolder1{
CheckBox checkBox;
TextView textView;
}
class viewHolder2{
TextView textView;
}
class viewHolder3{
ImageView imageView;
TextView textView;
}
}