Android入门之文件系统操作（一）简单的文件浏览器

     

1. import java.io.File;
   2. import java.util.*;
   3.
   4. import android.app.Activity;
   5. import android.content.Context;
   6. import android.os.*;
   7. import android.view.*;
   8. import android.widget.*;
   9. import android.widget.AdapterView.OnItemClickListener;
  10. import android.widget.ImageView.ScaleType;
  11.
  12. public class FileBrowser extends Activity {
  13.
  14.     private ListView mainListView=null;
  15.     private List<Map<String,Object>> list=null;
  16.
  17.     public void onCreate(Bundle savedInstanceState) {
  18.         super.onCreate(savedInstanceState);
  19.         this.setTitle("文件浏览器");
  20.         mainListView=new ListView(this);
  21.         setContentView(mainListView);
  22.
  23.         File file=Environment.getRootDirectory();
  24.         String pathx=file.getAbsolutePath();
  25.         this.setTitle(pathx);
  26.         //android的总目录就是"/"
  27.         list_init("/");
  28.     }
  29.
  30.     void list_init(String path){
  31.         File file=new File(path);
  32.         File[] fileList=file.listFiles();
  33.         list=new ArrayList<Map<String,Object>>();
  34.         Map<String,Object> item;
  35.         item=new HashMap<String,Object>();
  36.         if(path.equals("/")){
  37.             item.put("ico",R.drawable.home);
  38.             item.put("name","总目录列表");
  39.             item.put("path","/");
  40.             list.add(item);
  41.         }else{
  42.             item.put("ico",R.drawable.back);
  43.             item.put("name","返回上一级");
  44.             item.put("path",file.getParent());
  45.             list.add(item);
  46.         }
  47.         for(int i=0;i<fileList.length;i++){
  48.             item=new HashMap<String,Object>();
  49.             if(fileList[i].isDirectory()){
  50.                 if(fileList[i].list().length<1){
  51.                     item.put("ico",R.drawable.file1);
  52.                 }else{
  53.                     item.put("ico",R.drawable.file2);
  54.                 }
  55.             }else{
  56.                 item.put("ico",R.drawable.content);
  57.             }
  58.             item.put("name",fileList[i].getName());
  59.             item.put("path",fileList[i].getAbsolutePath());
  60.             list.add(item);
  61.         }
  62.         MyAdapter ma=new MyAdapter(this,list);
  63.         //mainListView=new ListView(this);
  64.         mainListView.setAdapter(ma);
  65.         mainListView.setOnItemClickListener(new OnItemClickListener(){
  66.             public void onItemClick(AdapterView<?> arg0, View arg1,int arg2, long arg3) {
  67.                 if(arg2>0 && (Integer)(list.get(arg2).get("ico"))==R.drawable.content){
  68.                     //非文件夹图标，点击无效
  69.                 }else{
  70.                     //打开下一级文件目录列表
  71.                     list_init((String)(list.get(arg2).get("path")));
  72.                 }
  73.             }
  74.         });
  75.         this.setTitle(path);
  76.     }
  77.
  78.     public class MyAdapter extends BaseAdapter{
  79.
  80.         Context context=null;
  81.         List<Map<String,Object>> list=null;
  82.
  83.         MyAdapter(Context context,List<Map<String,Object>> list){
  84.             this.context=context;
  85.             this.list=list;
  86.         }
  87.         public int getCount() {return list.size();}
  88.         public Object getItem(int position) {return position;}
  89.         public long getItemId(int position) {return position;}
  90.
  91.         public View getView(int position, View convertView, ViewGroup parent) {
  92.             LinearLayout returnView=new LinearLayout(context);
  93.             returnView.setLayoutParams(new ListView.LayoutParams(-1,-2));//注意:ListView.LayoutParams
  94.             //图标
  95.             ImageView iv=new ImageView(context);
  96.             LinearLayout.LayoutParams lp_iv=new LinearLayout.LayoutParams(-2,-2);
  97.             lp_iv.rightMargin=10;
  98.             iv.setLayoutParams(lp_iv);
  99.             iv.setScaleType(ScaleType.CENTER_INSIDE);
 100.             iv.setImageResource((Integer)((list.get(position)).get("ico")));
 101.             returnView.addView(iv);
 102.             //文件名
 103.             TextView name=new TextView(context);
 104.             LinearLayout.LayoutParams lp_tv=new LinearLayout.LayoutParams(-2,-2);
 105.             name.setLayoutParams(lp_tv);
 106.             name.setTextSize(name.getTextSize()+10);
 107.             name.setText((String)(list.get(position).get("name")));
 108.             returnView.addView(name);
 109.             //
 110.             return returnView;
 111.         }
 112.
 113.     }
 114. }