调用系统自带的文件浏览器
这很简单：

/** 调用文件选择软件来选择文件 **/ 
private void showFileChooser() { 
  intent = new Intent(Intent.ACTION_GET_CONTENT); 
  intent.setType("*/*"); 
  intent.addCategory(Intent.CATEGORY_OPENABLE); 
  try { 
    startActivityForResult(Intent.createChooser(intent, "请选择一个要上传的文件"), 
        FILE_SELECT_CODE); 
  } catch (android.content.ActivityNotFoundException ex) { 
    // Potentially direct the user to the Market with a Dialog 
    Toast.makeText(getActivity(), "请安装文件管理器", Toast.LENGTH_SHORT) 
        .show(); 
  } 
} 

在catch，我们可以做更多的操作，比如会跳转到一个下载文件管理器的页面或者等等。

对于返回的数据怎么处理呢。我项目中的上传是如下接收：

/** 根据返回选择的文件，来进行上传操作 **/ 
  @Override 
  public void onActivityResult(int requestCode, int resultCode, Intent data) { 
    // TODO Auto-generated method stub 
    if (resultCode == Activity.RESULT_OK) { 
      // Get the Uri of the selected file 
      Uri uri = data.getData(); 
      String url; 
      try { 
        url = FFileUtils.getPath(getActivity(), uri); 
        Log.i("ht", "url" + url); 
        String fileName = url.substring(url.lastIndexOf("/") + 1); 
        intent = new Intent(getActivity(), UploadServices.class); 
        intent.putExtra("fileName", fileName); 
        intent.putExtra("url", url); 
        intent.putExtra("type ", ""); 
        intent.putExtra("fuid", ""); 
        intent.putExtra("type", ""); 
 
        getActivity().startService(intent); 
 
      } catch (URISyntaxException e) { 
        // TODO Auto-generated catch block 
        e.printStackTrace(); 
      } 
    } 
    super.onActivityResult(requestCode, resultCode, data); 
  } 

   
自制文件浏览器：
这里只加一些简单的图形：

来看代码：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
  xmlns:tools="http://schemas.android.com/tools" 
  android:layout_width="match_parent" 
  android:layout_height="wrap_content" 
  android:orientation="vertical" 
  android:layout_gravity="center_horizontal" 
  tools:context=".MainActivity" > 
 
  <TextView 
    android:id="@+id/txt1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" /> 
  <ImageButton  
    android:id="@+id/imageBt1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:src="@drawable/home"/> 
 
  <ListView 
    android:id="@+id/listFile" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" > 
  </ListView> 
 
</LinearLayout> 

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
  android:layout_width="match_parent" 
  android:layout_height="match_parent" 
  android:orientation="horizontal" > 
 
  <ImageView 
    android:id="@+id/images" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" /> 
 
  <TextView 
    android:id="@+id/txtview" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" /> 
 
</LinearLayout> 

package com.android.xiong.sdfilelook; 
 
import java.io.File; 
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.os.Environment; 
import android.view.Menu; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.AdapterView; 
import android.widget.AdapterView.OnItemClickListener; 
import android.widget.ImageButton; 
import android.widget.ImageView; 
import android.widget.ListView; 
import android.widget.SimpleAdapter; 
import android.widget.TextView; 
 
public class MainActivity extends Activity { 
 
  private ListView listfile; 
  //当前文件目录 
  private String currentpath; 
  private TextView txt1; 
  private ImageView images; 
  private TextView textview; 
  private ImageButton imagebt1; 
 
  private int[] img = { R.drawable.file, R.drawable.folder, R.drawable.home }; 
  private File[] files; 
  private SimpleAdapter simple; 
 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    listfile = (ListView) findViewById(R.id.listFile); 
    txt1 = (TextView) findViewById(R.id.txt1); 
    imagebt1 = (ImageButton) findViewById(R.id.imageBt1); 
    init(Environment.getExternalStorageDirectory()); 
    listfile.setOnItemClickListener(new OnItemClickListener() { 
 
      @Override 
      public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, 
          long arg3) { 
        // TODO Auto-generated method stub 
        // 获取单击的文件或文件夹的名称 
        String folder = ((TextView) arg1.findViewById(R.id.txtview)) 
            .getText().toString(); 
        try { 
          File filef = new File(currentpath + '/' 
              + folder); 
          init(filef); 
 
        } catch (Exception e) { 
          e.printStackTrace(); 
        } 
 
      } 
    }); 
    //回根目录 
    imagebt1.setOnClickListener(new OnClickListener() { 
       
      @Override 
      public void onClick(View v) { 
        init(Environment.getExternalStorageDirectory());   
      } 
    }); 
     
  } 
  // 界面初始化 
  public void init(File f) { 
    if (Environment.getExternalStorageState().equals( 
        Environment.MEDIA_MOUNTED)) { 
      // 获取SDcard目录下所有文件名 
      files = f.listFiles(); 
      if (!files.equals(null)) { 
        currentpath=f.getPath(); 
        txt1.setText("当前目录为:"+f.getPath()); 
        List<Map<String, Object>> list = new ArrayList<Map<String, Object>>(); 
        for (int i = 0; i < files.length; i++) { 
          Map<String, Object> maps = new HashMap<String, Object>(); 
          if (files[i].isFile()) 
            maps.put("image", img[0]); 
          else 
            maps.put("image", img[1]); 
          maps.put("filenames", files[i].getName()); 
          list.add(maps); 
        } 
        simple = new SimpleAdapter(this, list, 
            R.layout.fileimageandtext, new String[] { "image", 
                "filenames" }, new int[] { R.id.images, 
                R.id.txtview }); 
        listfile.setAdapter(simple); 
 
      } 
    } else { 
      System.out.println("该文件为空"); 
    } 
  } 
 
  @Override 
  public boolean onCreateOptionsMenu(Menu menu) { 
    // Inflate the menu; this adds items to the action bar if it is present. 
    getMenuInflater().inflate(R.menu.main, menu); 
    return true; 
  } 
 
}