Android開發之--讀取文件夾下圖片生成略縮圖并點擊顯示大圖

這是一個簡單的Demo，目的是：讀取文件夾下圖片生成略縮圖并點擊顯示大圖。

 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 cn.embel.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() {

    /**
     * 顯示大圖時需要使用，當然可以直接在此類中定義！這樣還好控制一些~到時候再改吧，趕這過年呢
     */
    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);
}

/**
 * 定義按鈕控件的Touch事件
 */
OnTouchListener listener = new OnTouchListener() {
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        /**
         * 控件按下的時候顯示當前略縮圖的大圖
         */
        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;
    }
};

/**
 * 獲取圖片地址列表
 * @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;
}

/**
 * 讀取sdcard文件夾中的圖片，并生成略縮圖
 * @return
 * @throws FileNotFoundException
 */
private Map<String,Bitmap> buildThum() throws FileNotFoundException {
    File baseFile = new File("/mnt/sdcard/tflash/image/");
    // 使用TreeMap，排序問題就不需要糾結了
    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; // 設置了此屬性一定要記得將值設置為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;
}

}
 </pre> 
  修改mail.xml文件
<span style="font-size: 16px; "><?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android&quot;
    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></span></pre></span></span> 
  
 
  
本Demo還有Bug，稍后在修改吧，看能否經過修改，改成像Ihone圖片瀏覽器一樣的效果. 
 
 
  
源碼下載==》
 
  
原創文章，轉載請注明出處：http://blog.csdn.net/tangcheng_ok