android实现SDcard浏览器

package com.fog.sdexplorer; import java.io.File; import java.io.IOException; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.Button; import android.widget.ListView; import android.widget.SimpleAdapter; import android.widget.TextView; import android.widget.Toast; public class FogSDExplorerActivity extends Activity { /** Called when the activity is first created. */ ListView list; TextView path; File currentParent; File[] currentFiles; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); list=(ListView)findViewById(R.id.list); path=(TextView)findViewById(R.id.path); File root=new File("/mnt/sdcard"); if(root.exists()) { currentParent=root; currentFiles=root.listFiles(); inflateListView(currentFiles); } list.setOnItemClickListener(new OnItemClickListener() { public void onItemClick(AdapterView<?> parent, View view, int position, long id) { if(currentFiles[position].isFile()) return; File[] tmp=currentFiles[position].listFiles(); if(tmp==null || tmp.length==0) { Toast.makeText(FogSDExplorerActivity.this, "there is not file or the file is empty", 2000).show(); } else { currentParent=currentFiles[position]; currentFiles=tmp; inflateListView(currentFiles); } } }); Button parent=(Button)findViewById(R.id.parent); parent.setOnClickListener(new OnClickListener() { public void onClick(View v) { try { if(!currentParent.getCanonicalPath().equals("/mnt/sdcard")) { currentParent=currentParent.getParentFile(); currentFiles=currentParent.listFiles(); inflateListView(currentFiles); } } catch(IOException e) { e.printStackTrace(); } } }); } private void inflateListView(File[] files) { List<Map<String,Object>> listItems=new ArrayList<Map<String,Object>>(); for(int i=0;i<files.length;i++) { Map<String,Object> listItem=new HashMap<String,Object>(); if(files[i].isDirectory()) { listItem.put("icon", android.R.drawable.ic_lock_power_off); } else { listItem.put("icon", android.R.drawable.ic_lock_lock); } listItem.put("fileName", files[i].getName()); listItems.add(listItem); } SimpleAdapter simpleAdapter=new SimpleAdapter(this,listItems,R.layout.line, new String[]{"icon","fileName"}, new int[]{R.id.icon,R.id.file_name}); list.setAdapter(simpleAdapter); try { path.setText("the path is:"+currentParent.getCanonicalPath()); } catch(IOException e) { e.printStackTrace(); } } }