Android通过LIstView显示文件列表的两种方法介绍

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<TextView
android:id="@+id/Txt_Path"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="@string/hello" />
<Button
android:id="@+id/But_Up"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="向上" />
<ListView
android:id="@+id/List_View"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</ListView>
</LinearLayout>
main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/RelativeLayout1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<TextView
android:id="@+id/Txt_Size"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignParentTop="true"
android:text="TextView" />
<ImageView
android:id="@+id/image_ico"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_below="@+id/Txt_Size"
android:layout_marginLeft="18dp"
android:src="@drawable/folder" />
<TextView
android:id="@+id/Txt_Name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="@+id/image_ico"
android:layout_alignParentRight="true"
android:text="TextView" />
</RelativeLayout>
item.xml

package com.cqvie;
import java.io.File;
import java.util.LinkedList;
import java.util.List;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
public class File_Adter extends BaseAdapter {
public Activity activity; //创建View时必须要提供Context
public List<File> list=new LinkedList<File>(); //数据源（文件列表）
public String currPath;//当前路径
private Bitmap bmp_folder,bmp_file;
public int getCount() {
// TODO Auto-generated method stub
return list.size();
}
public Object getItem(int arg0) {
// TODO Auto-generated method stub
return null;
}
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
public View getView(int position, View arg1, ViewGroup arg2) {
// TODO Auto-generated method stub
View v=View.inflate(activity,R.layout.item,null);
TextView Txt_Name=(TextView) v.findViewById(R.id.Txt_Name);
TextView Txt_Size=(TextView) v.findViewById(R.id.Txt_Size);
ImageView img=(ImageView) v.findViewById(R.id.image_ico);
File f=list.get(position);
Txt_Name.setText(f.getName());
Txt_Size.setText(getFilesSize(f));
if(f.isDirectory())
img.setImageBitmap(bmp_folder);
else
img.setImageBitmap(bmp_file);
return v;
}
public void scanFiles(String path)
{
list.clear();
File dir=new File(path);
File[] subFiles=dir.listFiles();
if(subFiles!=null)
for(File f:subFiles)
list.add(f);
this.notifyDataSetChanged();
currPath=path;
}
public File_Adter(Activity activity)
{
this.activity=activity;
bmp_folder=BitmapFactory.decodeResource(activity.getResources(),R.drawable.folder);//文件夹,decodeResource图片解码，source资源，解码为Bitmap类型；
bmp_file=BitmapFactory.decodeResource(activity.getResources(),R.drawable.file);//文件
}
public static String getFilesSize(File f)
{
int sub_index=0;
String show="";
if(f.isFile())
{
long length=f.length();
if(length>=1073741824)
{
sub_index=String.valueOf((float)length/1073741824).indexOf(".");
show=((float)length/1073741824+"000").substring(0,sub_index+3)+"GB";
}
else if(length>=1048576)
{
sub_index=(String.valueOf((float)length/1048576)).indexOf(".");
show=((float)length/1048576+"000").substring(0,sub_index+3)+"GB";
}
else if(length>=1024)
{
sub_index=(String.valueOf((float)length/1024)).indexOf(".");
show=((float)length/1024+"000").substring(0,sub_index+3)+"GB";
}
else if(length<1024)
show=String.valueOf(length)+"B";
}
return show;
}
}
File_Adter.java

package com.cqvie;
import java.io.File;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
public class File_listActivity extends Activity implements OnItemClickListener, OnClickListener {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
List_View=(ListView) findViewById(R.id.List_View);
But_Up=(Button) findViewById(R.id.But_Up);
Txt_Path=(TextView) findViewById(R.id.Txt_Path);
File_Adter Adter=new File_Adter(this);
List_View.setAdapter(Adter);
List_View.setOnItemClickListener(this);
Adter.scanFiles("/");
But_Up.setOnClickListener(this);
}
ListView List_View;
TextView Txt_Path;
Button But_Up;
public void onClick(View v) {
// TODO Auto-generated method stub
File_Adter ad=(File_Adter) List_View.getAdapter();
if(ad.currPath.equals("/")) return;
File f=new File(ad.currPath);
Txt_Path.setText(f.getParent());
ad.scanFiles(f.getParent());
}
public void onItemClick(AdapterView<?> parent, View v, int positiong, long id) {
// TODO Auto-generated method stub
File_Adter da=(File_Adter) List_View.getAdapter();
File f=da.list.get(positiong);
if(f.isDirectory())
{
Txt_Path.setText(f.getPath());
da.scanFiles(f.getPath());
}
}
}
File_listActivity.java