Android入門之文件系統操作

Android入門之文件系統操作——簡單的文件浏覽器

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("文件浏覽器");  
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的總目錄就是"/"   
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","總目錄列表");    
39.             item.put("path","/");    
40.             list.add(item);  
41.         }else{  
42.             item.put("ico",R.drawable.back);   
43.             item.put("name","返回上一級");    
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.                     //非文件夾圖標，點擊無效   
69.                 }else{  
70.                     //打開下一級文件目錄列表   
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.             //圖標   
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. }