Android-简单的sdcard文件浏览

功能：能够浏览手机里面的文件夹和文件,代码灰常简单

先看布局

<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="match_parent"
    android:orientation="vertical"
    tools:context="com.example.fanlei.myservicedemo.FilePathActivity">

    <android.support.v7.widget.Toolbar
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="#000">
        <Button
            android:id="@+id/button"
            android:layout_width="wrap_content"
            android:layout_height="match_parent"
            android:text="返回上一级"/>
    </android.support.v7.widget.Toolbar>
    <ListView
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    </ListView>
</LinearLayout>

主函数

 package com.example.fanlei.myservicedemo;

 import android.annotation.TargetApi;
 import android.os.Build;
 import android.os.Bundle;
 import android.os.Environment;
 import android.support.v7.app.ActionBarActivity;
 import android.view.View;
 import android.widget.AdapterView;
 import android.widget.ArrayAdapter;
 import android.widget.Button;
 import android.widget.ListView;
 import android.widget.Toast;
 import java.io.File;
 import java.util.ArrayList;
 import java.util.List;

 public class FilePathActivity extends ActionBarActivity {

     private ListView listView;
     private File currentParent;   //记录父文件夹
     private File[] currentFiles;  //记录当前路径下的所有文件的文件数组
     private List<String> fileName;//文件或文件夹名字

     private ArrayAdapter arrayAdapter;
     private Button button;

     @TargetApi(Build.VERSION_CODES.KITKAT)
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_file_path);

         //判断一下有木有sdcard卡
         if (Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
             initView();
             initData();
             initEvent();
         }else {
             Toast.makeText(this,"无sdcard卡",Toast.LENGTH_LONG).show();
         }

     }

     private void initView(){
         listView = (ListView) findViewById(R.id.listView);
         button = (Button) findViewById(R.id.button);
     }

     private void initData(){
         currentParent = Environment.getExternalStorageDirectory();
         currentFiles = currentParent.listFiles();
         fileName = new ArrayList<>();
         List<String> temp = filesToFileName(currentFiles);
         fileName.addAll(temp);
         arrayAdapter = new ArrayAdapter(this,android.R.layout.simple_list_item_1,fileName);
         listView.setAdapter(arrayAdapter);
     }

     private void initEvent(){
         listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
             @Override
             public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                 if (!currentFiles[position].isFile()){
                     File[] temp = currentFiles[position].listFiles();
                     if (temp == null || temp.length == 0){
                         Toast.makeText(FilePathActivity.this,"该文件下已无文件",Toast.LENGTH_LONG).show();
                     }else {
                         currentParent = currentFiles[position];
                         currentFiles = temp;
                         fileName.clear();
                         fileName.addAll(filesToFileName(currentFiles));
                         arrayAdapter.notifyDataSetChanged();
                     }
                 }
             }
         });
         //返回键
         button.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
                 if (!currentParent.getPath().equals(Environment.getExternalStorageDirectory().getPath())){
                     currentParent = currentParent.getParentFile();
                     currentFiles = currentParent.listFiles();
                     fileName.clear();
                     fileName.addAll(filesToFileName(currentFiles));
                     arrayAdapter.notifyDataSetChanged();
                 }
             }
         });
     }
     //返回一个File的文件名的数组
     private List<String> filesToFileName(File[] files){
         List<String> fileName = new ArrayList<>();
         for (int i = 0;i < files.length;i++){
             if (!files[i].getName().substring(0,1).equals(".")){  //这个地方我把“.”开头的文件夹不让其显示
                 fileName.add(files[i].getName());
             }
         }
         return fileName;
     }
 }