Android应用中实现选择本地文件与目录的实例分享

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(); 
    } 
  } 
} 

<?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(); 
         
      } 
    }); 
  } 
}