android 图片浏览器 APP 源码

          该应用通过ImageSwitcher和Gallery控件，来显示手机sdcard中的图片。功能还不完善，目前仅支持，查看详细和删除，功能。仅供初学者学习。
    整个的工程的源码，在这里:http://download.csdn.net/detail/mci2004/4293560。由于我没有做过android的APP开发，所以这个应用是我参考了大量晚上代码和项目的结果。这里要补充一下，在我的项目中，有一个Debug.java文件，这个是开发初期调试用的，后来没用到了，希望不会给大家带来困扰。
    下面贴出部分源码：

 

//应用的入口   

package com.alan.android;import java.io.File;import java.text.SimpleDateFormat;import java.util.ArrayList;import java.util.Date;import java.util.HashMap;import android.app.Activity;import android.app.AlertDialog;import android.app.AlertDialog.Builder;import android.content.Context;import android.content.DialogInterface;import android.content.DialogInterface.OnClickListener;import android.content.res.TypedArray;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.graphics.drawable.Drawable;import android.os.Bundle;import android.os.Environment;import android.text.format.Formatter;import android.util.Log;import android.view.KeyEvent;import android.view.View;import android.view.ViewGroup;import android.view.animation.AnimationUtils;import android.widget.AdapterView;import android.widget.AdapterView.OnItemLongClickListener;import android.widget.AdapterView.OnItemSelectedListener;import android.widget.BaseAdapter;import android.widget.Gallery;import android.widget.Gallery.LayoutParams;import android.widget.ImageSwitcher;import android.widget.ImageView;import android.widget.TextView;import android.widget.Toast;import android.widget.ViewSwitcher.ViewFactory;/** * @author Alan * */public class ImageViewerActivity extends Activity implements ViewFactory, OnItemSelectedListener {private ImageSwitcher mImgSwitcher;private Gallery mGallery;private ImageAdapter adapter;private ArrayList<String> mImgPathList;private static boolean deleteHappen = false;//sdcard Pathprivate String mSdcardPath;//cache for the Bitmap resprivate HashMap<Integer, Bitmap> imgCache = new HashMap<Integer, Bitmap>();private static final String LOG_TAG="ImageViewer";    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                mImgPathList = new ArrayList<String>();        mSdcardPath  = Environment.getExternalStorageDirectory().toString();                 saveImagePathToList(mImgPathList, mSdcardPath);                //set ImageSwitcher        mImgSwitcher = (ImageSwitcher)findViewById(R.id.imgswitcher);        mImgSwitcher.setFactory(this);        mImgSwitcher.setInAnimation(AnimationUtils.loadAnimation(this,android.R.anim.fade_in));        mImgSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this,android.R.anim.fade_out));         //set Gallery        mGallery = (Gallery)findViewById(R.id.imgallery);        adapter = new ImageAdapter(this, mImgPathList);        mGallery.setAdapter(adapter);        mGallery.setOnItemSelectedListener(this);        mGallery.setOnItemLongClickListener(new OnItemLongClickListener(){public boolean onItemLongClick(AdapterView<?> arg0, View arg1,final int position, long id) {// TODO Auto-generated method stubAlertDialog.Builder build = new Builder(ImageViewerActivity.this);build.setTitle("ä½ æƒ³æ‰§è¡Œä¸‹åˆ—å“ªä¸ªæ“ä½œï¼Ÿ").setPositiveButton("åˆ é™¤é€‰ä¸­æ–‡ä»¶", new OnClickListener(){public void onClick(DialogInterface dialog, int which) {// TODO Auto-generated method stubonDelBtnDown(position);}}).setNegativeButton("详细信息", new OnClickListener(){public void onClick(DialogInterface dialog, int which) {// TODO Auto-generated method stubonDetailBtnDown(position);}});build.create().show();return false;}                });    }        //button down callbacksprivate void onDetailBtnDown(int pos) {// TODO Auto-generated method stubfinal View d = View.inflate(this, R.layout.detailsview,null);//Thumbnail ViewImageView imageView = (ImageView) d.findViewById(                R.id.details_thumbnail_image);Bitmap bm = BitmapFactory.decodeFile(mImgPathList.get(pos));imageView.setImageBitmap(bm);//Text View of Image TitleTextView txTitle = (TextView) d.findViewById(R.id.details_image_title);txTitle.setText(geTitle(pos));//the picture resolution valueint width = bm.getWidth();int height = bm.getHeight();String pictureSize = width + "*" + height;setDetailsValue(d, pictureSize, R.id.details_resolution_value);//the picture sizeString size = Formatter.formatFileSize(this, height*width);setDetailsValue(d, size, R.id.details_file_size_value);//get dateString value = null;File f = new File(mImgPathList.get(pos));long lastMod = f.lastModified();if (lastMod != 0) {            Date date = new Date(lastMod);            SimpleDateFormat dateFormat = new SimpleDateFormat();            value = dateFormat.format(date);        }        if (value != null) {            setDetailsValue(d, value, R.id.details_date_taken_value);        } else {            hideDetailsRow(d, R.id.details_date_taken_row);        }AlertDialog.Builder build = new Builder(ImageViewerActivity.this);build.setTitle("详细信息").setView(d).show();}private static void setDetailsValue(View d, String text, int valueId) {        ((TextView) d.findViewById(valueId)).setText(text);    }    private static void hideDetailsRow(View d, int rowId) {        d.findViewById(rowId).setVisibility(View.GONE);    }private String geTitle(int pos){String title = mImgPathList.get(pos);int last_s = title.lastIndexOf("/");int last_l = title.lastIndexOf(".");title = title.substring(last_s + 1, last_l);return title;}private void onDelBtnDown(int pos) {// TODO Auto-generated method stubdeleteHappen = true;Log.d(LOG_TAG,"the pos will deleted is " + pos);File current = new File(mImgPathList.get(pos));current.delete();mImgPathList.remove(pos);adapter.notifyDataSetChanged();mGallery.setAdapter(adapter);if(pos == 0 && mImgPathList.size() == 0){mImgSwitcher.setImageDrawable(null);Toast.makeText(this, "The Picture isn't exist, or Deleted",                    Toast.LENGTH_SHORT).show();}}        //get image path recursivelyprivate void saveImagePathToList(ArrayList<String> list, String filePath) {// TODO Auto-generated method stubFile mFile = new File(filePath);File[] listFile = mFile.listFiles();if(listFile != null){for(int i = 0 ; i < listFile.length ; i++){File file = listFile[i];if(isAnImageFile(file.getAbsolutePath())){list.add(file.getAbsolutePath());}else if(file.isDirectory() && !file.getAbsolutePath().contains("DCIM")){//get image path recursivelythis.saveImagePathToList(mImgPathList, file.getAbsolutePath());}continue;}}}//check the fils's suffix and tell whether it's an imageprivate boolean isAnImageFile(String fileName){String fileNameLowerCase = fileName.toLowerCase();if(fileNameLowerCase.endsWith("jpg") || fileNameLowerCase.endsWith("gif") || fileNameLowerCase.endsWith("bmp") || fileNameLowerCase.endsWith("jpeg")|| fileNameLowerCase.endsWith("png")){return true;}return false;}public View makeView() {// TODO Auto-generated method stubImageView iv = new ImageView(this);           //iv.setBackgroundColor(0xFF000000);           iv.setScaleType(ImageView.ScaleType.FIT_CENTER);           iv.setLayoutParams(new ImageSwitcher.LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.MATCH_PARENT));           return iv;   }public class ImageAdapter extends BaseAdapter{private Context mContext;private int mGalleryBackground;private ArrayList<String> mArrayList;public ImageAdapter(Context c, ArrayList<String> list){mContext = c;mArrayList = list;//use attrs.xml to specify the Gallery's attributesTypedArray mTypeArray = obtainStyledAttributes(R.styleable.Gallery);mGalleryBackground = mTypeArray.getResourceId(R.styleable.Gallery_android_galleryItemBackground, 0);mTypeArray.recycle();}public int getCount() {// TODO Auto-generated method stubreturn mArrayList.size();}public Object getItem(int position) {// TODO Auto-generated method stubreturn position;}public long getItemId(int position) {// TODO Auto-generated method stubreturn position;}public View getView(int position, View convertView, ViewGroup parent) {// TODO Auto-generated method stub//new a ImageView for the image displayingLog.d(LOG_TAG,"getView--->and pos = " + position);ImageView imgView = new ImageView(mContext);Bitmap current = imgCache.get(position);if(deleteHappen || current == null){current = BitmapFactory.decodeFile(mArrayList.get(position));Log.e(LOG_TAG,"decodeFile path = " + mArrayList.get(position));imgCache.put(position, current);}imgView.setImageBitmap(current);imgView.setScaleType(ImageView.ScaleType.FIT_XY);imgView.setLayoutParams(new Gallery.LayoutParams(136, 88));imgView.setBackgroundResource(mGalleryBackground);//deleteHappen = false;return imgView;}}public void onItemSelected(AdapterView<?> arg0, View arg1, int pos,long id) {// TODO Auto-generated method stubString imgPath = mImgPathList.get(pos);Log.e(LOG_TAG,"Selected Img position is " + pos + "Image Path = " + imgPath);Drawable drawadle = Drawable.createFromPath(imgPath);mImgSwitcher.setImageDrawable(drawadle); //release Bitmap resourcereleaseBitmap();}//just keep the bitmap in Visible range, release the restprivate void releaseBitmap() {// TODO Auto-generated method stubint begin = mGallery.getFirstVisiblePosition();int end = mGallery.getLastVisiblePosition();for(int i = 0 ; i < begin ; i++){Bitmap delBitmap = imgCache.get(i);if(delBitmap != null){imgCache.remove(i);delBitmap.recycle(); adapter.notifyDataSetChanged();}}for(int i = end + 1 ; i < imgCache.size() ; i++){Bitmap delBitmap = imgCache.get(i);if(delBitmap != null){imgCache.remove(i);delBitmap.recycle();}}}public void onNothingSelected(AdapterView<?> arg0) {// TODO Auto-generated method stubLog.e(LOG_TAG,"onNothingSelected...");}@Overridepublic boolean onKeyDown(int keyCode, KeyEvent event) {// TODO Auto-generated method stubswitch(keyCode){case KeyEvent.KEYCODE_BACK:AlertDialog.Builder builder = new AlertDialog.Builder(this);builder.setTitle("Are you sure want to quit!");builder.setCancelable(true);        builder.setPositiveButton("Yes", new OnClickListener(){public void onClick(DialogInterface dialog, int which) {ImageViewerActivity.this.finish();}                });        builder.setNegativeButton("No", null);        builder.show();}return super.onKeyDown(keyCode, event);}@Overrideprotected void onDestroy() {// TODO Auto-generated method stubsuper.onDestroy();}@Overrideprotected void onPause() {// TODO Auto-generated method stubsuper.onPause();}}

 

        还有一些资源文件，我就不贴了，不是我偷懒，因为上个网实在是太不容易了。关于这个应用，以及一些android应用开发的体会，我后面还会发一篇文章来说说自己的想法。

         老规矩，大牛没欢迎指正我blog中的错误哈。谢谢了先....