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;
    }
}