瀑布流代码,Java代码库,德仔网

代码语言
代码分类
【Java】瀑布流
作者:爱4妮 / 发布于2015/1/4/ 453

	package com.xiaoyun.org.app.ui;
	
	import java.io.BufferedInputStream;
	import java.io.BufferedOutputStream;
	import java.io.File;
	import java.io.FileOutputStream;
	import java.io.IOException;
	import java.io.InputStream;
	import java.net.HttpURLConnection;
	import java.net.URL;
	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.HashSet;
	import java.util.LinkedList;
	import java.util.List;
	import java.util.Set;
	
	import org.json.JSONArray;
	import org.json.JSONObject;
	
	import com.alibaba.fastjson.JSON;
	import com.nostra13.universalimageloader.core.DisplayImageOptions;
	import com.nostra13.universalimageloader.core.assist.ImageScaleType;
	import com.nostra13.universalimageloader.core.display.FadeInBitmapDisplayer;
	import com.nostra13.universalimageloader.core.display.SimpleBitmapDisplayer;
	import com.nostra13.universalimageloader.core.listener.ImageLoadingListener;
	import com.nostra13.universalimageloader.core.listener.SimpleImageLoadingListener;
	import com.xiaoyun.org.R;
	import com.xiaoyun.org.app.bean.ImageData;
	import com.xiaoyun.org.app.common.Constant;
	import com.xiaoyun.org.app.common.UIHelper;
	import com.xiaoyun.org.util.HttpUtil;
	import com.xiaoyun.org.util.ImageLoader;
	
	import android.content.Context;
	import android.content.Intent;
	import android.graphics.Bitmap;
	import android.graphics.drawable.Drawable;
	import android.os.AsyncTask;
	import android.os.Environment;
	import android.os.Handler;
	import android.os.Message;
	import android.util.AttributeSet;
	import android.util.Log;
	import android.view.MotionEvent;
	import android.view.View;
	import android.view.View.OnTouchListener;
	import android.widget.ImageView;
	import android.widget.ImageView.ScaleType;
	import android.widget.LinearLayout;
	import android.widget.ScrollView;
	import android.widget.Toast;
	
	/**
	* 自定义的ScrollView，在其中动态地对图片进行添加。
	*
	* @author guolin
	*/
	public class MyScrollView extends ScrollView implements OnTouchListener {
	
	 /**
	 * 每页要加载的图片数量
	 */
	 public static final int PAGE_SIZE = 15;
	
	 /**
	 * 记录当前已加载到第几页
	 */
	 private int page;
	
	 /**
	 * 每一列的宽度
	 */
	 private int columnWidth;
	
	 /**
	 * 当前第一列的高度
	 */
	 private int firstColumnHeight;
	
	 /**
	 * 当前第二列的高度
	 */
	 private int secondColumnHeight;
	
	 /**
	 * 当前第三列的高度
	 */
	 private int thirdColumnHeight;
	
	 /**
	 * 是否已加载过一次layout，这里onLayout中的初始化只需加载一次
	 */
	 private boolean loadOnce;
	
	 /**
	 * 对图片进行管理的工具类
	 */
	 private ImageLoader imageLoader;
	
	 /**
	 * 第一列的布局
	 */
	 private LinearLayout firstColumn;
	
	 /**
	 * 第二列的布局
	 */
	 private LinearLayout secondColumn;
	
	 /**
	 * 第三列的布局
	 */
	 private LinearLayout thirdColumn;
	
	 /**
	 * 记录所有正在下载或等待下载的任务。
	 */
	 private static Set<LoadImageTask> taskCollection;
	
	 /**
	 * MyScrollView下的直接子布局。
	 */
	 private static View scrollLayout;
	
	 /**
	 * MyScrollView布局的高度。
	 */
	 private static int scrollViewHeight;
	
	 /**
	 * 记录上垂直方向的滚动距离。
	 */
	 private static int lastScrollY = -1;
	
	 /**
	 * 记录所有界面上的图片，用以可以随时控制对图片的释放。
	 */
	 private List<ImageView> imageViewList = new ArrayList<ImageView>();
	
	 private final static int INIT_LOAD = 1;
	
	 List<ImageData> data = new ArrayList<ImageData>();
	 String[] imageUrls = new String[Constant.DATA_SIZE];
	
	 private DisplayImageOptions options;
	 private ImageLoadingListener animateFirstListener = new AnimateFirstDisplayListener();
	
	 /**
	 * 在Handler中进行图片可见性检查的判断，以及加载更多图片的操作。
	 */
	 private static Handler handler = new Handler() {
	
	 public void handleMessage(android.os.Message msg) {
	 MyScrollView myScrollView = (MyScrollView) msg.obj;
	 int scrollY = myScrollView.getScrollY();
	 // 如果当前的滚动位置和上次相同，表示已停止滚动
	 if (scrollY == lastScrollY) {
	 // 当滚动的最底部，并且当前没有正在下载的任务时，开始加载下一页的图片
	 if (scrollViewHeight + scrollY >= scrollLayout.getHeight()
	 && taskCollection.isEmpty()) {
	 myScrollView.loadMoreImages();
	 }
	 myScrollView.checkVisibility();
	 } else {
	 lastScrollY = scrollY;
	 Message message = new Message();
	 message.obj = myScrollView;
	 // 5毫秒后再次对滚动位置进行判断
	 handler.sendMessageDelayed(message, 5);
	 }
	 };
	
	 };
	
	 /**
	 * MyScrollView的构造函数。
	 *
	 * @param context
	 * @param attrs
	 */
	 public MyScrollView(Context context, AttributeSet attrs) {
	 super(context, attrs);
	
	 options = new DisplayImageOptions.Builder()
	 .showImageOnFail(R.drawable.empty_photo).cacheInMemory(true)
	 .cacheOnDisk(true).considerExifParams(true)
	 .bitmapConfig(Bitmap.Config.RGB_565).delayBeforeLoading(10)
	 .displayer(new SimpleBitmapDisplayer())// //正常显示一张图片　
	 .build();
	
	 imageLoader = ImageLoader.getInstance();
	 taskCollection = new HashSet<LoadImageTask>();
	 setOnTouchListener(this);
	 }
	
	 /**
	 * 进行一些关键性的初始化操作，获取MyScrollView的高度，以及得到第一列的宽度值。并在这里开始加载第一页的图片。
	 */
	 @Override
	 protected void onLayout(boolean changed, int l, int t, int r, int b) {
	 super.onLayout(changed, l, t, r, b);
	 if (changed && !loadOnce) {
	 scrollViewHeight = getHeight();
	 scrollLayout = getChildAt(0);
	 firstColumn = (LinearLayout) findViewById(R.id.first_column);
	 secondColumn = (LinearLayout) findViewById(R.id.second_column);
	 thirdColumn = (LinearLayout) findViewById(R.id.third_column);
	 columnWidth = firstColumn.getWidth();
	 loadOnce = true;
	 loadHandler.obtainMessage(INIT_LOAD).sendToTarget();
	
	 }
	 }
	
	 private Handler loadHandler = new Handler() {
	 @Override
	 public void handleMessage(Message msg) {
	 switch (msg.what) {
	 case INIT_LOAD:
	 loadData(Constant.planet, Constant.WidthAndHeight);
	 break;
	
	 default:
	 break;
	 }
	 super.handleMessage(msg);
	 }
	 };
	
	 /**
	 * 获取全部的图片数据
	 *
	 * @param account
	 * @param pwd
	 * @param isRememberMe
	 */
	 private void loadData(final String planets, final String widthandheight) {
	
	 final Handler handler = new Handler() {
	 public void handleMessage(Message msg) {
	 Object obj = msg.obj;
	 if (msg.what == 1) {
	 for (int i = 0; i < data.size() - 1; i++) {
	 imageUrls[i] = data.get(i).getDownload_url();
	 }
	 loadMoreImages();
	 }
	 if (msg.what == -1) {
	 UIHelper.ToastMessage(getContext(), "加载失败");
	 }
	 }
	 };
	 new Thread() {
	 public void run() {
	 Message msg = Message.obtain();
	 int what = -1;
	 Object obj = "获取数据失败";
	 String url = planets + "&" + widthandheight;
	 String Content = "";
	
	 JSONObject mJsonObject;
	 try {
	 data.clear();
	 Content = HttpUtil.getContent(url);
	 mJsonObject = new JSONObject(Content);
	 JSONArray mJsonArray = mJsonObject.getJSONArray("data");
	 ImageData imageData = null;
	 for (int k = 0; k < mJsonArray.length(); k++) {
	 JSONObject objs = mJsonArray.getJSONObject(k);
	 imageData = JSON.parseObject(objs.toString(),
	 ImageData.class);
	 data.add(imageData);
	 }
	 what = 1;
	 } catch (Exception e) {
	 e.printStackTrace();
	 }
	 msg.what = what;
	 msg.obj = obj;
	 handler.sendMessage(msg);
	 }
	 }.start();
	
	 }
	
	 /**
	 * 监听用户的触屏事件，如果用户手指离开屏幕则开始进行滚动检测。
	 */
	 @Override
	 public boolean onTouch(View v, MotionEvent event) {
	 if (event.getAction() == MotionEvent.ACTION_UP) {
	 Message message = new Message();
	 message.obj = this;
	 handler.sendMessageDelayed(message, 5);
	 }
	 return false;
	 }
	
	 /**
	 * 开始加载下一页的图片，每张图片都会开启一个异步线程去下载。
	 */
	 public void loadMoreImages() {
	 if (hasSDCard()) {
	 int startIndex = page * PAGE_SIZE;
	 int endIndex = page * PAGE_SIZE + PAGE_SIZE;
	 if (startIndex < imageUrls.length) {
	 UIHelper.ToastMessage(getContext(), "正在加载&hellip;&hellip;");
	 if (endIndex > imageUrls.length) {
	 endIndex = imageUrls.length;
	 }
	
	 for (int i = startIndex; i < endIndex; i++) {
	 LoadImageTask task = new LoadImageTask();
	 taskCollection.add(task);
	 task.execute(imageUrls[i]);
	 }
	 page++;
	 } else {
	 UIHelper.ToastMessage(getContext(), "已没有更多图片");
	 }
	 } else {
	 UIHelper.ToastMessage(getContext(), "未发现SD卡");
	 }
	 }
	
	 /**
	 * 遍历imageViewList中的每张图片，对图片的可见性进行检查，如果图片已经离开屏幕可见范围，则将图片替换成一张空图。
	 */
	 public void checkVisibility() {
	 for (int i = 0; i < imageViewList.size(); i++) {
	 ImageView imageView = imageViewList.get(i);
	 int borderTop = (Integer) imageView.getTag(R.string.border_top);
	 int borderBottom = (Integer) imageView
	 .getTag(R.string.border_bottom);
	 if (borderBottom > getScrollY()
	 && borderTop < getScrollY() + scrollViewHeight) {
	 String imageUrl = (String) imageView.getTag(R.string.image_url);
	 com.nostra13.universalimageloader.core.ImageLoader
	 .getInstance().displayImage(imageUrl, imageView,
	 options, animateFirstListener);
	 } else {
	 imageView.setImageResource(R.drawable.empty_photo);
	 }
	 }
	 }
	
	 /**
	 * 判断手机是否有SD卡。
	 *
	 * @return 有SD卡返回true，没有返回false。
	 */
	 private boolean hasSDCard() {
	 return Environment.MEDIA_MOUNTED.equals(Environment
	 .getExternalStorageState());
	 }
	
	 /**
	 * 异步下载图片的任务。
	 *
	 * @author guolin
	 */
	 class LoadImageTask extends AsyncTask<String, Void, Bitmap> {
	
	 /**
	 * 图片的URL地址
	 */
	 private String mImageUrl;
	
	 /**
	 * 可重复使用的ImageView
	 */
	 private ImageView mImageView;
	
	 public LoadImageTask() {
	 }
	
	 /**
	 * 将可重复使用的ImageView传入
	 *
	 * @param imageView
	 */
	 public LoadImageTask(ImageView imageView) {
	 mImageView = imageView;
	 }
	
	 @Override
	 protected Bitmap doInBackground(String... params) {
	 mImageUrl = params[0];
	 return null;
	 }
	
	 @Override
	 protected void onPostExecute(Bitmap bitmap) {
	 addImage(bitmap, columnWidth, Constant.height/3);
	 taskCollection.remove(this);
	 }
	
	 /**
	 * 向ImageView中添加一张图片
	 *
	 * @param bitmap
	 * 待添加的图片
	 * @param imageWidth
	 * 图片的宽度
	 * @param imageHeight
	 * 图片的高度
	 */
	 private void addImage(Bitmap bitmap, int imageWidth, int imageHeight) {
	 LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(
	 imageWidth, imageHeight);
	 if (mImageView != null) {
	 com.nostra13.universalimageloader.core.ImageLoader
	 .getInstance().displayImage(mImageUrl, mImageView,
	 options, animateFirstListener);
	 } else {
	 ImageView imageView = new ImageView(getContext());
	 imageView.setLayoutParams(params);
	 imageView.setScaleType(ScaleType.FIT_XY);
	 imageView.setPadding(5, 5, 5, 5);
	 imageView.setTag(R.string.image_url, mImageUrl);
	 findColumnToAdd(imageView, imageHeight).addView(imageView);
	
	 imageViewList.add(imageView);
	 com.nostra13.universalimageloader.core.ImageLoader
	 .getInstance().displayImage(mImageUrl, imageView,
	 options, animateFirstListener);
	 //downloadImage(mImageUrl);
	 imageView.setOnClickListener(new OnClickListener() {
	
	 @Override
	 public void onClick(View v) {
	 // TODO Auto-generated method stub
	 String imageUrl = mImageUrl;
	 Intent intent = new Intent(getContext(),
	 ImageScaleActivity.class);
	 if ("null".equals(imageUrl)) {
	 imageUrl = "http://h.hiphotos.baidu.com/image/pic/item/4bed2e738bd4b31c4859e0ba85d6277f9e2ff84e.jpg";
	 }
	 intent.putExtra("filePath", imageUrl);
	 getContext().startActivity(intent);
	 }
	 });
	 }
	
	 }
	
	 /**
	 * 找到此时应该添加图片的一列。原则就是对三列的高度进行判断，当前高度最小的一列就是应该添加的一列。
	 *
	 * @param imageView
	 * @param imageHeight
	 * @return 应该添加图片的一列
	 */
	 private LinearLayout findColumnToAdd(ImageView imageView,
	 int imageHeight) {
	 if (firstColumnHeight <= secondColumnHeight) {
	 if (firstColumnHeight <= thirdColumnHeight) {
	 imageView.setTag(R.string.border_top, firstColumnHeight);
	 firstColumnHeight += imageHeight;
	 imageView.setTag(R.string.border_bottom, firstColumnHeight);
	 return firstColumn;
	 }
	 imageView.setTag(R.string.border_top, thirdColumnHeight);
	 thirdColumnHeight += imageHeight;
	 imageView.setTag(R.string.border_bottom, thirdColumnHeight);
	 return thirdColumn;
	 } else {
	 if (secondColumnHeight <= thirdColumnHeight) {
	 imageView.setTag(R.string.border_top, secondColumnHeight);
	 secondColumnHeight += imageHeight;
	 imageView
	 .setTag(R.string.border_bottom, secondColumnHeight);
	 return secondColumn;
	 }
	 imageView.setTag(R.string.border_top, thirdColumnHeight);
	 thirdColumnHeight += imageHeight;
	 imageView.setTag(R.string.border_bottom, thirdColumnHeight);
	 return thirdColumn;
	 }
	 }
	
	 /**
	 * 将图片下载到SD卡缓存起来。
	 *
	 * @param imageUrl
	 * 图片的URL地址。
	 */
	 private void downloadImage(String imageUrl) {
	 if (Environment.getExternalStorageState().equals(
	 Environment.MEDIA_MOUNTED)) {
	 Log.d("TAG", "monted sdcard");
	 } else {
	 Log.d("TAG", "has no sdcard");
	 }
	 HttpURLConnection con = null;
	 FileOutputStream fos = null;
	 BufferedOutputStream bos = null;
	 BufferedInputStream bis = null;
	 File imageFile = null;
	 try {
	
	 imageFile = new File(getImagePath(imageUrl));
	 // 初始化一个URL对象
	 URL mUrl = new URL(imageUrl);
	 // 获得HTTPConnection网络连接对象
	 HttpURLConnection conn = (HttpURLConnection) mUrl
	 .openConnection();
	 // conn.setDoInput(true);
	 // conn.connect();
	 conn.setConnectTimeout(5000);
	 conn.setRequestMethod("GET");
	 conn.setDoInput(true);
	 conn.connect();
	
	 if (conn.getResponseCode() == 200) {
	 // 得到输入流 然后写入sd卡
	 InputStream is = conn.getInputStream();
	 fos = new FileOutputStream(imageFile);
	 byte[] buffer = new byte[1024 * 2];
	 int len = 0;
	 while ((len = is.read(buffer)) != -1) {
	 fos.write(buffer, 0, len);
	 }
	 // 关闭输入流
	 is.close();
	 fos.close();
	 }
	 // 关闭连接
	 conn.disconnect();
	
	 } catch (Exception e) {
	 // TODO: handle exception
	 e.printStackTrace();
	 }
	
	 if (imageFile != null) {
	 Bitmap bitmap = ImageLoader.decodeSampledBitmapFromResource(
	 imageFile.getPath(), columnWidth);
	 if (bitmap != null) {
	 imageLoader.addBitmapToMemoryCache(imageUrl, bitmap);
	 }
	 }
	 }
	
	 /**
	 * 获取图片的本地存储路径。
	 *
	 * @param imageUrl
	 * 图片的URL地址。
	 * @return 图片的本地存储路径。
	 */
	 private String getImagePath(String imageUrl) {
	 int lastSlashIndex = imageUrl.lastIndexOf("/");
	 String imageName = imageUrl.substring(lastSlashIndex + 1);
	 String imageDir = Environment.getExternalStorageDirectory()
	 .getPath() + "/51mzt/";
	 File file = new File(imageDir);
	 if (!file.exists()) {
	 file.mkdirs();
	 }
	 String imagePath = imageDir + imageName;
	 return imagePath;
	 }
	 }
	
	 private static class AnimateFirstDisplayListener extends
	 SimpleImageLoadingListener {
	
	 static final List<String> displayedImages = Collections
	 .synchronizedList(new LinkedList<String>());
	
	 @Override
	 public void onLoadingComplete(String imageUri, View view,
	 Bitmap loadedImage) {
	 if (loadedImage != null) {
	 ImageView imageView = (ImageView) view;
	 boolean firstDisplay = !displayedImages.contains(imageUri);
	 if (firstDisplay) {
	 FadeInBitmapDisplayer.animate(imageView, 500);
	 displayedImages.add(imageUri);
	 }
	 }
	 }
	 }
	
	}
试试其它关键字
　瀑布流　
同语言下
可能有用的
爱4妮贡献的其它代码(1)
.瀑布流