安卓应用中的文件与目录选择器 Android应用中实现选择本地文件与目录的实例分享
qinjuning 人气:0想了解Android应用中实现选择本地文件与目录的实例讲解的相关内容吗,qinjuning在本文为您仔细讲解安卓应用中的文件与目录选择器的相关知识和一些Code实例,欢迎阅读和指正,我们先划重点:Android,文件,目录,选择器,下面大家一起来学习吧。
文件选择器
今天给大家分享下文件选择器的作用 , 具体就是获取用户在在SD卡选中的文件/文件夹路径 ,类似于C#中OpenFileDialog控件(对C#的一站式开发还是念念不忘)。功能实现起来比较简单,主要是帮助大家节省开发时间。
网上流传较广的一个成品如下 <[Android实例] 文件选择器>, 本文也是根据上面的成品修改而成,使其更易理解,效率更高。 除此之外,主要特色有:
1、我们监听了用户按下Back键的事件,使其返回上一层目录;
2、针对不同的文件类型(文件vs文件夹 , 目标文件vs其他文件)做了特殊处理。
知识点一、 File 类的使用
文件选择器的主要功能是:浏览文件\文件夹、文件类型等;都是通过Java File类来实现的。
知识点二、调用方法说明
使用了startActivityForResult()发起调用以及onActivityResult()方法接受回调后的信息。
截图如下:
其他的也没什么好说了,大家看看代码注释吧~~ so easy - - 。
FileChooserActivity.java 实现文件选择的类 。
public class CopyOfFileChooserActivity extends Activity { private String mSdcardRootPath ; //sdcard 根路径 private String mLastFilePath ; //当前显示的路径 private ArrayList<FileInfo> mFileLists ; private FileChooserAdapter mAdatper ; //配置适配器 private void setGridViewAdapter(String filePath) { updateFileItems(filePath); mAdatper = new FileChooserAdapter(this , mFileLists); mGridView.setAdapter(mAdatper); } //根据路径更新数据,并且通知Adatper数据改变 private void updateFileItems(String filePath) { mLastFilePath = filePath ; mTvPath.setText(mLastFilePath); if(mFileLists == null) mFileLists = new ArrayList<FileInfo>() ; if(!mFileLists.isEmpty()) mFileLists.clear() ; File[] files = folderScan(filePath); if(files == null) return ; for (int i = 0; i < files.length; i++) { if(files[i].isHidden()) // 不显示隐藏文件 continue ; String fileAbsolutePath = files[i].getAbsolutePath() ; String fileName = files[i].getName(); boolean isDirectory = false ; if (files[i].isDirectory()){ isDirectory = true ; } FileInfo fileInfo = new FileInfo(fileAbsolutePath , fileName , isDirectory) ; //添加至列表 mFileLists.add(fileInfo); } //When first enter , the object of mAdatper don't initialized if(mAdatper != null) mAdatper.notifyDataSetChanged(); //重新刷新 } //获得当前路径的所有文件 private File[] folderScan(String path) { File file = new File(path); File[] files = file.listFiles(); return files; } private AdapterView.OnItemClickListener mItemClickListener = new OnItemClickListener() { public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) { FileInfo fileInfo = (FileInfo)(((FileChooserAdapter)adapterView.getAdapter()).getItem(position)); if(fileInfo.isDirectory()) //点击项为文件夹, 显示该文件夹下所有文件 updateFileItems(fileInfo.getFilePath()) ; else if(fileInfo.isPPTFile()){ //是ppt文件 , 则将该路径通知给调用者 Intent intent = new Intent(); intent.putExtra(EXTRA_FILE_CHOOSER, fileInfo.getFilePath()); setResult(RESULT_OK , intent); finish(); } else { //其他文件..... toast(getText(R.string.open_file_error_format)); } } }; public boolean onKeyDown(int keyCode , KeyEvent event){ if(event.getAction() == KeyEvent.ACTION_DOWN && event.getKeyCode() == KeyEvent.KEYCODE_BACK){ backProcess(); return true ; } return super.onKeyDown(keyCode, event); } //返回上一层目录的操作 public void backProcess(){ //判断当前路径是不是sdcard路径 , 如果不是,则返回到上一层。 if (!mLastFilePath.equals(mSdcardRootPath)) { File thisFile = new File(mLastFilePath); String parentFilePath = thisFile.getParent(); updateFileItems(parentFilePath); } else { //是sdcard路径 ,直接结束 setResult(RESULT_CANCELED); finish(); } } }
界面依旧很丑陋,囧 ,大家可以根据需要在此基础上添加功能,下面选择目录也基本上同理。
目录选择器
chooserdialog.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="vertical" android:layout_width="fill_parent" android:layout_height="fill_parent" > <LinearLayout android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="40dip"> <Button android:layout_width="40dip" android:layout_height="40dip" android:text="HOME" android:id="@+id/btn_home" android:layout_gravity="left" android:layout_weight="1" /> <LinearLayout android:layout_width="140dip" android:layout_height="35dip" android:id="@+id/dir_layout" android:gravity="center" android:layout_weight="1"> </LinearLayout> <!-- <TextView android:layout_width="140dip" android:layout_height="35dip" android:id="@+id/dir_str" android:gravity="center" android:layout_weight="1" /> --> <Button android:layout_width="40dip" android:layout_height="40dip" android:text="BACK" android:id="@+id/btn_back" android:layout_gravity="right" android:layout_weight="1" /> </LinearLayout> <ListView android:layout_width="fill_parent" android:layout_height="300dip" android:id="@+id/list_dir" /> <Button android:layout_width="fill_parent" android:layout_height="wrap_content" android:id="@+id/btn_ok" android:text="OK"/> </LinearLayout>
package hkp.dirchooser; import java.io.File; import java.util.ArrayList; import java.util.List; import android.app.Dialog; import android.content.Context; import android.os.Bundle; import android.os.Environment; import android.os.Handler; import android.view.Gravity; import android.view.View; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.ArrayAdapter; import android.widget.Button; import android.widget.EditText; import android.widget.LinearLayout; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; public class DirChooserDialog extends Dialog implements android.view.View.OnClickListener{ private ListView list; ArrayAdapter<String> Adapter; ArrayList<String> arr=new ArrayList<String>(); Context context; private String path; private TextView title; private EditText et; private Button home,back,ok; private LinearLayout titleView; private int type = 1; private String[] fileType = null; public final static int TypeOpen = 1; public final static int TypeSave = 2; /** * @param context * @param type 值为1表示创建打开目录类型的对话框,2为创建保存文件到目录类型的对话框 * @param fileType 要过滤的文件类型,null表示只选择目录 * @param resultPath 点OK按钮返回的结果,目录或者目录+文件名 */ public DirChooserDialog(Context context,int type,String[]fileType,String resultPath) { super(context); // TODO Auto-generated constructor stub this.context = context; this.type = type; this.fileType = fileType; this.path = resultPath; } /* (non-Javadoc) * @see android.app.Dialog#dismiss() */ @Override public void dismiss() { // TODO Auto-generated method stub super.dismiss(); } /* (non-Javadoc) * @see android.app.Dialog#onCreate(android.os.Bundle) */ @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.chooserdialog); path = getRootDir(); arr = (ArrayList<String>) getDirs(path); Adapter = new ArrayAdapter<String>(context,android.R.layout.simple_list_item_1, arr); list = (ListView)findViewById(R.id.list_dir); list.setAdapter(Adapter); list.setOnItemClickListener(lvLis); home = (Button) findViewById(R.id.btn_home); home.setOnClickListener(this); back = (Button) findViewById(R.id.btn_back); back.setOnClickListener(this); ok = (Button) findViewById(R.id.btn_ok); ok.setOnClickListener(this); titleView = (LinearLayout) findViewById(R.id.dir_layout); if(type == TypeOpen){ title = new TextView(context); titleView.addView(title); title.setText(path); }else if(type == TypeSave){ et = new EditText(context); et.setWidth(240); et.setHeight(70); et.setGravity(Gravity.CENTER); et.setPadding(0, 2, 0, 0); titleView.addView(et); et.setText("wfFileName"); } // title = (TextView) findViewById(R.id.dir_str); // title.setText(path); } //动态更新ListView Runnable add=new Runnable(){ @Override public void run() { // TODO Auto-generated method stub arr.clear(); //System.out.println("Runnable path:"+path); //必须得用这种方法为arr赋值才能更新 List<String> temp = getDirs(path); for(int i = 0;i < temp.size();i++) arr.add(temp.get(i)); Adapter.notifyDataSetChanged(); } }; private OnItemClickListener lvLis=new OnItemClickListener(){ @Override public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) { String temp = (String) arg0.getItemAtPosition(arg2); //System.out.println("OnItemClick path1:"+path); if(temp.equals("..")) path = getSubDir(path); else if(path.equals("/")) path = path+temp; else path = path+"/"+temp; //System.out.println("OnItemClick path2"+path); if(type == TypeOpen) title.setText(path); Handler handler=new Handler(); handler.post(add); } }; private List<String> getDirs(String ipath){ List<String> file = new ArrayList<String>(); //System.out.println("GetDirs path:"+ipath); File[] myFile = new File(ipath).listFiles(); if(myFile == null){ file.add(".."); }else for(File f: myFile){ //过滤目录 if(f.isDirectory()){ String tempf = f.toString(); int pos = tempf.lastIndexOf("/"); String subTemp = tempf.substring(pos+1, tempf.length()); // String subTemp = tempf.substring(path.length(),tempf.length()); file.add(subTemp); //System.out.println("files in dir:"+subTemp); } //过滤知道类型的文件 if(f.isFile() && fileType != null){ for(int i = 0;i< fileType.length;i++){ int typeStrLen = fileType[i].length(); String fileName = f.getPath().substring(f.getPath().length()- typeStrLen); if (fileName.toLowerCase().equals(fileType[i])) { file.add(f.toString().substring(path.length()+1,f.toString().length())); } } } } if(file.size()==0) file.add(".."); // System.out.println("file[0]:"+file.get(0)+" File size:"+file.size()); return file; } /* (non-Javadoc) * @see android.view.View.OnClickListener#onClick(android.view.View) */ @Override public void onClick(View v) { // TODO Auto-generated method stub if(v.getId() == home.getId()){ path = getRootDir(); if(type == TypeOpen) title.setText(path); Handler handler=new Handler(); handler.post(add); }else if(v.getId() == back.getId()){ path = getSubDir(path); if(type == TypeOpen) title.setText(path); Handler handler=new Handler(); handler.post(add); }else if(v.getId() == ok.getId()){ dismiss(); if(type == TypeSave) path = path+"/"+et.getEditableText().toString()+".wf"; Toast.makeText(context, path, Toast.LENGTH_SHORT).show(); } } private String getSDPath(){ File sdDir = null; boolean sdCardExist = Environment.getExternalStorageState() .equals(android.os.Environment.MEDIA_MOUNTED); //判断sd卡是否存在 if(sdCardExist) { sdDir = Environment.getExternalStorageDirectory();//获取根目录 } if(sdDir == null){ //Toast.makeText(context, "No SDCard inside!",Toast.LENGTH_SHORT).show(); return null; } return sdDir.toString(); } private String getRootDir(){ String root = "/"; path = getSDPath(); if (path == null) path="/"; return root; } private String getSubDir(String path){ String subpath = null; int pos = path.lastIndexOf("/"); if(pos == path.length()){ path = path.substring(0,path.length()-1); pos = path.lastIndexOf("/"); } subpath = path.substring(0,pos); if(pos == 0) subpath = path; return subpath; } }
package hkp.dirchooser; import android.app.Activity; import android.os.Bundle; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; public class MainActivity extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Button btn = (Button) findViewById(R.id.btn_open); btn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub String path = null; String [] fileType = {"dst"};//要过滤的文件类型列表 DirChooserDialog dlg = new DirChooserDialog(MainActivity.this,2,fileType,path); dlg.setTitle("Choose dst file dir"); dlg.show(); } }); } }
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