这是一个简单的Demo，目的是：读取文件夹下图片生成略缩图并点击显示大图。
先新建一个工程，创建一个ThumbnailsWindows的类，继承LinearLayout。代码如下：
package org.winplus.thum.view;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.Map;
import java.util.TreeMap;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.LinearLayout;
import org.winplus.thum.R;
public class ThumbnailsWindows extends LinearLayout {
private static final String TAG = "ThumbnailsWindows";
private Context mContext;
private static ArrayList<String> paths = new ArrayList<String>();
private ImageView imageView;
public ThumbnailsWindows(Context context) {
super(context);
mContext = context;
setupViews();
}
public ThumbnailsWindows(Context context, AttributeSet attrs) {
super(context, attrs);
mContext = context;
setupViews();
}
public void setupViews() {
/**
* 显示大图时需要使用，当然可以直接在此类中定义！这样还好控制一些~到时候再改吧，赶这过年呢
*/
final LayoutInflater mLayoutInflater = LayoutInflater.from(getContext());
View v = mLayoutInflater.inflate(R.layout.original_photo, null);
imageView = (ImageView) v.findViewById(R.id.original);
Map<String,Bitmap> maps = new TreeMap<String, Bitmap>();
try {
maps = buildThum();
} catch (FileNotFoundException e) {
e.printStackTrace();
}
Iterator<String> it = maps.keySet().iterator();
int i = 0;
while (it.hasNext()) {
String path = (String) it.next();
Bitmap bm = maps.get(path);
ImageButton image = new ImageButton(mContext);
image.setImageBitmap(bm);
image.setId(i++);
addView(image);
image.setOnTouchListener(listener);
}
addView(v);
}
/**
* 定义按钮控件的Touch事件
*/
OnTouchListener listener = new OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
/**
* 控件按下的时候显示当前略缩图的大图
*/
if(event.getAction() == MotionEvent.ACTION_DOWN){
String path = paths.get(v.getId());
InputStream inputStream = null;
try {
inputStream = new FileInputStream(path);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
imageView.setImageBitmap(bitmap);
}
return false;
}
};
/**
* 获取图片地址列表
* @param file
* @return
*/
private static ArrayList<String> imagePath(File file) {
ArrayList<String> list = new ArrayList<String>();
File[] files = file.listFiles();
for (File f : files) {
list.add(f.getAbsolutePath());
}
Collections.sort(list);
return list;
}
/**
* 读取sdcard文件夹中的图片，并生成略缩图
* @return
* @throws FileNotFoundException
*/
private Map<String,Bitmap> buildThum() throws FileNotFoundException {
File baseFile = new File("/mnt/sdcard/tflash/image/");
// 使用TreeMap，排序问题就不需要纠结了
Map<String,Bitmap> maps = new TreeMap<String, Bitmap>();
if (baseFile != null && baseFile.exists()) {
paths = imagePath(baseFile);
if (!paths.isEmpty()) {
for (int i = 0; i < paths.size(); i++) {
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true; // 设置了此属性一定要记得将值设置为false
Bitmap bitmap =BitmapFactory.decodeFile(paths.get(i),options);
options.inJustDecodeBounds = false;
int be = options.outHeight/40;
if (be <= 0) {
be = 10;
}
options.inSampleSize = be;
bitmap = BitmapFactory.decodeFile(paths.get(i),options);
maps.put(paths.get(i), bitmap);
}
}
}
return maps;
}
}
修改mail.xml文件
<?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" > <org.winplus.thum.view.ThumbnailsWindows android:layout_width="fill_parent" android:layout_height="fill_parent" /> </LinearLayout>
本Demo还有Bug，稍后在修改吧，看能否经过修改，改成像Ihone图片浏览器一样的效果.
好了，本文就写到这里，提前预祝各位春节快乐！