setListAdapter()老是显示有误

setListAdapter()总是显示有误
package cn.com.qw;

import java.util.ArrayList;
import java.util.HashMap;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.ListView;
import android.widget.SimpleAdapter;

public class ListviewActivity extends Activity {
  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.main);
   
  ArrayList<HashMap<String,String>> list=null;
  list=new ArrayList<HashMap<String,String>>();
  HashMap<String,String> map1=new HashMap<String,String>();
  ListView listView=(ListView)findViewById(R.id.list);
  map1.put("user_name","张三");
  map1.put("user_ip","1234567");
   
  HashMap<String,String> map2=new HashMap<String,String>();
  map2.put("user_name","王五");
  map2.put("user_ip","2345467");
   
  list.add(map1);
  list.add(map2);
   
  SimpleAdapter listAdapter=new SimpleAdapter(this,list,
  R.layout.user,new String[]{"user_name","user_ip"},new int[]{R.id.user_name,R.id.user_ip});
  list.setListAdapter(listAdapter);
  }
}

[解决办法]
list.setListAdapter(listAdapter);
应为：listView.setListAdapter(listAdapter);

[解决办法]