也发一个自己实现的android简单文件选择器代码。支持多卡，排序

　　一个很简单的文件选择器对话框，支持双sd卡，当然前提是要有sd卡。。并且实现了排序效果.
只有100多行的代码，基本的思路就是用listview显示目录下的所有子文件，再判断是文件还是目录。
利用Collections.sort方法进行排序。
代码如下:
  1 package net.yunstudio.demo;
  2 
  3 import java.io.File;
  4 import java.text.Collator;
  5 import java.util.ArrayList;
  6 import java.util.Collections;
  7 import java.util.Comparator;
  8 import java.util.HashMap;
  9 import java.util.List;
 10 import java.util.Locale;
 11 import java.util.Map;
 12 
 13 
 14 import android.app.Dialog;
 15 import android.content.Context;
 16 import android.os.Environment;
 17 import android.text.TextUtils;
 18 import android.util.Log;
 19 import android.view.View;
 20 import android.widget.AdapterView;
 21 import android.widget.AdapterView.OnItemClickListener;
 22 import android.widget.ListView;
 23 import android.widget.SimpleAdapter;
 24 
 25 public class FilePickerDialog extends Dialog implements OnItemClickListener{
 26 
 27     public FilePickerDialog(Context context) {
 28         super(context);
 29         init();
 30     }
 31     
 32     
 33     private ListView lv_file;
 34     private SimpleAdapter simpleAdapter;
 35     private List<Map<String, Object>> dataList;
 36     private OnFileSelectListener listener;
 37     //通过获取sd卡的父级，可以兼容双sd卡的情况
 38     private static final File rootPath=
 39             Environment.getExternalStorageDirectory().getParentFile(); 
 40     
 41     private static final String SRC="src"; 
 42     private static final String NAME="name";
 43     private static final String FILE="file";
 44     private static final String IS_BAK="isBak";
 45     
 46     private void init() {
 47         getChildren2dataList(rootPath);
 48         simpleAdapter=new SimpleAdapter(getContext(),dataList , R.layout.list_item_choosefile, 
 49                 new String[]{SRC,NAME}, new int[]{R.id.iv_file_type,R.id.tv_file_name});
 50         
 51         lv_file=new ListView(getContext());
 52         lv_file.setAdapter(simpleAdapter);
 53         lv_file.setOnItemClickListener(this);
 54         setContentView(lv_file);
 55         
 56         setCanceledOnTouchOutside(true);
 57         this.setTitle("请选择文件");
 58     }
 59     /**
 60      * 设置选择文件的监听器
 61      * @param listener
 62      */
 63     public void setOnFileSelectListener(OnFileSelectListener listener) {
 64         this.listener = listener;
 65     }
 66     /**
 67      * 将本目录的子文件的信息赋值给dataList字段
 68      * @param dir
 69      */
 70     private void getChildren2dataList(File dir) {
 71         File[] children=dir.listFiles();
 72         if(dataList==null){
 73             dataList=new ArrayList<Map<String,Object>>();
 74         }else {
 75             dataList.clear();
 76         }    
 77         
 78         if(!rootPath.equals(dir)){
 79             Map<String, Object> map=new HashMap<String, Object>();
 80             map.put(SRC, R.drawable.folder);
 81             map.put(NAME, "..");
 82             map.put(FILE, dir.getParentFile());
 83             map.put(IS_BAK, true);
 84             dataList.add(map);
 85         }
 86         if(children==null) return ;//避免空目录引起的空指针错误
 87         for (File file : children) {
 88             Map<String, Object> map=new HashMap<String, Object>();
 89             map.put(SRC, file.isDirectory()
 90                                 ?R.drawable.folder
 91                                 :R.drawable.file);
 92             map.put(NAME, file.getName());
 93             map.put(FILE, file);
 94             dataList.add(map);
 95         }
 96         
 97         
 98         Collections.sort(dataList, new Comparator<Map<String, Object>>() {
 99 
100             @Override
101             public int compare(Map<String, Object> lhs, Map<String, Object> rhs) {
102                 int result=0;
103                 
104                 if(lhs.get(IS_BAK)!=null){
105                     result = -1;
106                 }else if (rhs.get(IS_BAK)!=null) {
107                     result = 1;
108                 }else {
109                     File lhsFile=(File) lhs.get(FILE);
110                     File rhsFile=(File) rhs.get(FILE);  
111                     
112                     if(lhsFile.isDirectory()&&rhsFile.isFile()){
113                         result = -1;
114                     }else if (lhsFile.isFile()&&rhsFile.isDirectory()) {
115                         result = 1;
116                     }else {
117                         Collator cmp = Collator.getInstance(Locale.getDefault());  
118                         result = cmp.compare(lhs.get(NAME), rhs.get(NAME));
119                     }
120                 }
121                 return result;
122             }
123         });
124     }
125 
126     @Override
127     public void onItemClick(AdapterView<?> parent, View view, int position,
128             long id) {
129         File file=(File)dataList.get(position).get(FILE);
130         if(file.isDirectory()){
131             getChildren2dataList(file);
132             simpleAdapter.notifyDataSetChanged();
133         }else {
134             if(listener!=null){
135                 listener.onFileSelect(file);
136                 this.dismiss();
137             }
138         }
139     }
140     
141     public static interface OnFileSelectListener{
142         void onFileSelect(File file);
143     }
144 }
View Code
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