listview改變字型大小

效果：點擊字型，字型變大

主要利用的getView()方法和setOnItemClickListener()方法

ListText.java

package lt.com;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import android.app.Activity;import android.app.AlertDialog;import android.app.ListActivity;import android.content.Context;import android.content.DialogInterface;import android.os.Bundle;import android.util.Log;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.AdapterView;import android.widget.BaseAdapter;import android.widget.Button;import android.widget.ImageView;import android.widget.ListView;import android.widget.TextView;import android.widget.AdapterView.OnItemClickListener;public class ListText extends Activity {List<Map<String,Object>> mData;public static int select_item = -1;//MyAdapter adapter;    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        ListView lv=(ListView)findViewById(R.id.lv) ;        mData= GetDate();        final MyAdapter adapter =new MyAdapter(this);        lv.setAdapter(adapter);        Log.v("tag", "100");                //點擊事件        lv.setOnItemClickListener(new OnItemClickListener(){             public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,               long arg3) {       select_item = arg2; //當前選擇的item    adapter.notifyDataSetChanged(); //通知adapter重新整理資料         Log.v("tag", "1");     }     public void onNothingSelected(AdapterView<?> arg0) {            }                         });             }          //item相關資訊  名稱 圖片    public  List<Map<String,Object>>  GetDate(){               List<Map<String,Object>> list=new ArrayList<Map<String,Object>>(); //存在一個大倉庫，擺放著很多抽屜 ，list相當把抽屜放進倉庫。                                                                          // 這是upcast 或者ArrayList<Map<String,Object>> list=new ArrayList<Map<String,Object>>();也行                 Map<String,Object>  map=new HashMap<String,Object>();//抽屜，裡面有東西。         map.put("text", "中國");//把東西放到抽屜裡面         list.add(map);//把抽屜放到倉庫裡                  HashMap<String,Object> map1=new HashMap<String,Object>();         map1.put("text", "美國");         list.add(map1);                  HashMap<String,Object> map2=new HashMap<String,Object>();          map2.put("text", "日本");         list.add(map2);             return list;    }    //自訂配接器    public class MyAdapter extends BaseAdapter{             private LayoutInflater mInflater;//Instantiates a layout XML file into its corresponding View objects. private int select_item;public MyAdapter(Context context){this.mInflater = LayoutInflater.from(context);//Obtains the LayoutInflater from the given context.}        //item的數量public int getCount() {// TODO Auto-generated method stubreturn mData.size();}public Object getItem(int arg0) {// TODO Auto-generated method stubreturn null;}public long getItemId(int position) {// TODO Auto-generated method stubreturn 0;}//convertView是複用的view，如果沒有舊的就建立個新的view；parent是listviewpublic View getView(int position, View convertView, ViewGroup parent) {// TODO Auto-generated method stubViewHolder holder = null;if(convertView==null){    holder=new ViewHolder();   convertView=mInflater.inflate(R.layout.main, null);//Inflate a new view hierarchy from the specified xml resource.    holder.texta = (TextView)convertView.findViewById(R.id.text);convertView.setTag(holder);//Sets the tag associated with this view ，  A tag can be used to mark a view in its hierarchy and does not have to be unique within the hierarchy.                           //這個view是holder繪製的}else{holder = (ViewHolder)convertView.getTag();//get tag} holder.texta.setText((String)mData.get(position).get("text")); this.select_item = ListText.select_item;try{        if(this.select_item == position){            holder.texta.setTextSize(50);   //選中的Item字型：50px            Log.v("tag", "3");        }        else            holder.texta.setTextSize(20);   //未選中的Item字型：10px            Log.v("tag", "2");    }catch(Exception ex){        ex.printStackTrace();    }  return convertView;} }    /** listView 中某項被選中後的邏輯protected void onListItemClick(ListView l, View v, int position, long id) {select_item = position; //當前選擇的item   // adapter.notifyDataSetChanged(); //通知adapter重新整理資料 Log.v("tag", "1");}*/    public final class ViewHolder{    TextView texta;        }      }

main.xml

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="fill_parent"    android:layout_height="fill_parent"    android:orientation="vertical" >   <ListView     android:id="@+id/lv"   android:layout_width="match_parent"   android:layout_height="match_parent"         >    </ListView>      <TextView        android:id="@+id/text"        android:layout_width="fill_parent"        android:layout_height="wrap_content"         /></LinearLayout>