一、介绍 Android-Universal-Image-Loader是一个开源的UI组件程序,该项目的目的是提供一个可重复使用的仪器为异步图像加载,缓存和显示。所以,如果你的程序里需要这个功能的话,那么不妨试试它。因为已经封装好了一些类和方法。我们 可以直接拿来用了。而不用重复去写了。其实,写一个这方面的程序还是比较麻烦的,要考虑多线程缓存,内存溢出等很多方面。 二、具体使用一个好的类库的重要特征就是可配置性强。我们先简单使用Android-Universal-Image-Loader,一般情况下使用默认配置就可以了。 下面的实例利用Android-Universal-Image-Loader将网络图片加载到图片墙中。
- public class BaseActivity extends Activity {
- ImageLoader imageLoader;
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- // Create global configuration and initialize ImageLoader with this configuration
- ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(getApplicationContext())
- .build();
- ImageLoader.getInstance().init(config);
- super.onCreate(savedInstanceState);
- }
- }
复制代码- public class MainActivity extends BaseActivity {
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.activity_main);
-
- ImageLoader imageLoader = ImageLoader.getInstance();
- GridView gridView = (GridView) this.findViewById(R.id.grdvImageWall);
- gridView.setAdapter(new PhotoWallAdapter(Constants.IMAGES));
- }
- static class ViewHolder {
- ImageView imageView;
- ProgressBar progressBar;
- }
- public class PhotoWallAdapter extends BaseAdapter {
- String[] imageUrls;
- ImageLoader imageLoad;
- DisplayImageOptions options;
- LinearLayout gridViewItem;
- public PhotoWallAdapter(String[] imageUrls) {
- assert imageUrls != null;
- this.imageUrls = imageUrls;
- options = new DisplayImageOptions.Builder()
- .showImageOnLoading(R.drawable.ic_stub) // resource or
- // drawable
- .showImageForEmptyUri(R.drawable.ic_empty) // resource or
- // drawable
- .showImageOnFail(R.drawable.ic_error) // resource or
- // drawable
- .resetViewBeforeLoading(false) // default
- .delayBeforeLoading(1000).cacheInMemory(false) // default
- .cacheOnDisk(false) // default
- .considerExifParams(false) // default
- .imageScaleType(ImageScaleType.IN_SAMPLE_POWER_OF_2) // default
- .bitmapConfig(Bitmap.Config.ARGB_8888) // default
- .displayer(new SimpleBitmapDisplayer()) // default
- .handler(new Handler()) // default
- .build();
- this.imageLoad = ImageLoader.getInstance();
- }
- @Override
- public int getCount() {
- return this.imageUrls.length;
- }
- @Override
- public Object getItem(int position) {
- if (position <= 0 || position >= this.imageUrls.length) {
- throw new IllegalArgumentException(
- "position<=0||position>=this.imageUrls.length");
- }
- return this.imageUrls[position];
- }
- @Override
- public long getItemId(int position) {
- return position;
- }
- @Override
- public View getView(int position, View convertView, ViewGroup parent) {
- // 判断这个image是否已经在缓存当中,如果没有就下载
- final ViewHolder holder;
- if (convertView == null) {
- holder = new ViewHolder();
- gridViewItem = (LinearLayout) getLayoutInflater().inflate(
- R.layout.image_wall_item, null);
- holder.imageView = (ImageView) gridViewItem
- .findViewById(R.id.item_image);
- holder.progressBar = (ProgressBar) gridViewItem
- .findViewById(R.id.item_process);
- gridViewItem.setTag(holder);
- convertView = gridViewItem;
- } else {
- holder = (ViewHolder) gridViewItem.getTag();
- }
- this.imageLoad.displayImage(this.imageUrls[position],
- holder.imageView, options,
- new SimpleImageLoadingListener() {
- @Override
- public void onLoadingStarted(String imageUri, View view) {
- holder.progressBar.setProgress(0);
- holder.progressBar.setVisibility(View.VISIBLE);
- }
- @Override
- public void onLoadingFailed(String imageUri, View view,
- FailReason failReason) {
- holder.progressBar.setVisibility(View.GONE);
- }
- @Override
- public void onLoadingComplete(String imageUri,
- View view, Bitmap loadedImage) {
- holder.progressBar.setVisibility(View.GONE);
- }
- }, new ImageLoadingProgressListener() {
- @Override
- public void onProgressUpdate(String imageUri,
- View view, int current, int total) {
- holder.progressBar.setProgress(Math.round(100.0f
- * current / total));
- }
- }); // 通过URL判断图片是否已经下载
- return convertView;
- }
- }
- }
复制代码里面主要的对象都用 突出显示了。 三者的关系ImageLoaderConfiguration是针对图片缓存的全局配置,主要有线程类、缓存大小、磁盘大小、图片下载与解析、日志方面的配置。 ImageLoader是具体下载图片,缓存图片,显示图片的具体执行类,它有两个具体的方法displayImage(...)、loadImage(...),但是其实最终他们的实现都是displayImage(...)。 DisplayImageOptions用于指导每一个Imageloader根据网络图片的状态(空白、下载错误、正在下载)显示对应的图片,是否将缓存加载到磁盘上,下载完后对图片进行怎么样的处理。 从三者的协作关系上看,他们有点像厨房规定、厨师、客户个人口味之间的关系。ImageLoaderConfiguration就像是厨房里面的规定,每一个厨师要怎么着装,要怎么保持厨房的干净,这是针对每一个厨师都适用的规定,而且不允许个性化改变。ImageLoader就像是具体做菜的厨师,负责具体菜谱的制作。DisplayImageOptions就像每个客户的偏好,根据客户是重口味还是清淡,每一个imageLoader根据DisplayImageOptions的要求具体执行。
ImageLoaderConfiguration在上面的示例代码中,我们使用ImageLoaderConfiguration的默认配置,下面给出ImageLoaderConfiguration比较详尽的配置,从下面的配置中,可以看出ImageLoaderConfiguration的配置主要是全局性的配置,主要有线程类、缓存大小、磁盘大小、图片下载与解析、日志方面的配置。 - ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(context)
- .memoryCacheExtraOptions(480, 800) // default = device screen dimensions
- .diskCacheExtraOptions(480, 800, null)
- .taskExecutor(...)
- .taskExecutorForCachedImages(...)
- .threadPoolSize(3) // default
- .threadPriority(Thread.NORM_PRIORITY - 1) // default
- .tasksProcessingOrder(QueueProcessingType.FIFO) // default
- .denyCacheImageMultipleSizesInMemory()
- .memoryCache(new LruMemoryCache(2 * 1024 * 1024))
- .memoryCacheSize(2 * 1024 * 1024)
- .memoryCacheSizePercentage(13) // default
- .diskCache(new UnlimitedDiscCache(cacheDir)) // default
- .diskCacheSize(50 * 1024 * 1024)
- .diskCacheFileCount(100)
- .diskCacheFileNameGenerator(new HashCodeFileNameGenerator()) // default
- .imageDownloader(new BaseImageDownloader(context)) // default
- .imageDecoder(new BaseImageDecoder()) // default
- .defaultDisplayImageOptions(DisplayImageOptions.createSimple()) // default
- .writeDebugLogs()
- .build();
复制代码ImageLoaderConfiguration的主要职责就是记录相关的配置,它的内部其实就是一些字段的集合(如下面的源代码)。它有一个builder的内部类,这个类中的字段跟ImageLoaderConfiguration中的字段完全一致,它有一些默认值,通过修改builder可以配置ImageLoaderConfiguration。 - /*******************************************************************************
- * Copyright 2011-2013 Sergey Tarasevich
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- *******************************************************************************/
- package com.nostra13.universalimageloader.core;
- import android.content.Context;
- import android.content.res.Resources;
- import android.util.DisplayMetrics;
- import com.nostra13.universalimageloader.cache.disc.DiskCache;
- import com.nostra13.universalimageloader.cache.disc.naming.FileNameGenerator;
- import com.nostra13.universalimageloader.cache.memory.MemoryCache;
- import com.nostra13.universalimageloader.cache.memory.impl.FuzzyKeyMemoryCache;
- import com.nostra13.universalimageloader.core.assist.FlushedInputStream;
- import com.nostra13.universalimageloader.core.assist.ImageSize;
- import com.nostra13.universalimageloader.core.assist.QueueProcessingType;
- import com.nostra13.universalimageloader.core.decode.ImageDecoder;
- import com.nostra13.universalimageloader.core.download.ImageDownloader;
- import com.nostra13.universalimageloader.core.process.BitmapProcessor;
- import com.nostra13.universalimageloader.utils.L;
- import com.nostra13.universalimageloader.utils.MemoryCacheUtils;
- import java.io.IOException;
- import java.io.InputStream;
- import java.util.concurrent.Executor;
- /**
- * Presents configuration for {@link ImageLoader}
- *
- * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
- * @see ImageLoader
- * @see MemoryCache
- * @see DiskCache
- * @see DisplayImageOptions
- * @see ImageDownloader
- * @see FileNameGenerator
- * @since 1.0.0
- */
- public final class ImageLoaderConfiguration {
- final Resources resources;
- final int maxImageWidthForMemoryCache;
- final int maxImageHeightForMemoryCache;
- final int maxImageWidthForDiskCache;
- final int maxImageHeightForDiskCache;
- final BitmapProcessor processorForDiskCache;
- final Executor taskExecutor;
- final Executor taskExecutorForCachedImages;
- final boolean customExecutor;
- final boolean customExecutorForCachedImages;
- final int threadPoolSize;
- final int threadPriority;
- final QueueProcessingType tasksProcessingType;
- final MemoryCache memoryCache;
- final DiskCache diskCache;
- final ImageDownloader downloader;
- final ImageDecoder decoder;
- final DisplayImageOptions defaultDisplayImageOptions;
- final ImageDownloader networkDeniedDownloader;
- final ImageDownloader slowNetworkDownloader;
- private ImageLoaderConfiguration(final Builder builder) {
- resources = builder.context.getResources();
- maxImageWidthForMemoryCache = builder.maxImageWidthForMemoryCache;
- maxImageHeightForMemoryCache = builder.maxImageHeightForMemoryCache;
- maxImageWidthForDiskCache = builder.maxImageWidthForDiskCache;
- maxImageHeightForDiskCache = builder.maxImageHeightForDiskCache;
- processorForDiskCache = builder.processorForDiskCache;
- taskExecutor = builder.taskExecutor;
- taskExecutorForCachedImages = builder.taskExecutorForCachedImages;
- threadPoolSize = builder.threadPoolSize;
- threadPriority = builder.threadPriority;
- tasksProcessingType = builder.tasksProcessingType;
- diskCache = builder.diskCache;
- memoryCache = builder.memoryCache;
- defaultDisplayImageOptions = builder.defaultDisplayImageOptions;
- downloader = builder.downloader;
- decoder = builder.decoder;
- customExecutor = builder.customExecutor;
- customExecutorForCachedImages = builder.customExecutorForCachedImages;
- networkDeniedDownloader = new NetworkDeniedImageDownloader(downloader);
- slowNetworkDownloader = new SlowNetworkImageDownloader(downloader);
- L.writeDebugLogs(builder.writeLogs);
- }
- /**
- * Creates default configuration for {@link ImageLoader} <br />
- * <b>Default values:</b>
- * <ul>
- * <li>maxImageWidthForMemoryCache = device's screen width</li>
- * <li>maxImageHeightForMemoryCache = device's screen height</li>
- * <li>maxImageWidthForDikcCache = unlimited</li>
- * <li>maxImageHeightForDiskCache = unlimited</li>
- * <li>threadPoolSize = {@link Builder#DEFAULT_THREAD_POOL_SIZE this}</li>
- * <li>threadPriority = {@link Builder#DEFAULT_THREAD_PRIORITY this}</li>
- * <li>allow to cache different sizes of image in memory</li>
- * <li>memoryCache = {@link DefaultConfigurationFactory#createMemoryCache(int)}</li>
- * <li>diskCache = {@link com.nostra13.universalimageloader.cache.disc.impl.UnlimitedDiscCache}</li>
- * <li>imageDownloader = {@link DefaultConfigurationFactory#createImageDownloader(Context)}</li>
- * <li>imageDecoder = {@link DefaultConfigurationFactory#createImageDecoder(boolean)}</li>
- * <li>diskCacheFileNameGenerator = {@link DefaultConfigurationFactory#createFileNameGenerator()}</li>
- * <li>defaultDisplayImageOptions = {@link DisplayImageOptions#createSimple() Simple options}</li>
- * <li>tasksProcessingOrder = {@link QueueProcessingType#FIFO}</li>
- * <li>detailed logging disabled</li>
- * </ul>
- */
- public static ImageLoaderConfiguration createDefault(Context context) {
- return new Builder(context).build();
- }
- ImageSize getMaxImageSize() {
- DisplayMetrics displayMetrics = resources.getDisplayMetrics();
- int width = maxImageWidthForMemoryCache;
- if (width <= 0) {
- width = displayMetrics.widthPixels;
- }
- int height = maxImageHeightForMemoryCache;
- if (height <= 0) {
- height = displayMetrics.heightPixels;
- }
- return new ImageSize(width, height);
- }
- /**
- * Builder for {@link ImageLoaderConfiguration}
- *
- * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
- */
- public static class Builder {
- private static final String WARNING_OVERLAP_DISK_CACHE_PARAMS = "diskCache(), diskCacheSize() and diskCacheFileCount calls overlap each other";
- private static final String WARNING_OVERLAP_DISK_CACHE_NAME_GENERATOR = "diskCache() and diskCacheFileNameGenerator() calls overlap each other";
- private static final String WARNING_OVERLAP_MEMORY_CACHE = "memoryCache() and memoryCacheSize() calls overlap each other";
- private static final String WARNING_OVERLAP_EXECUTOR = "threadPoolSize(), threadPriority() and tasksProcessingOrder() calls "
- + "can overlap taskExecutor() and taskExecutorForCachedImages() calls.";
- /** {@value} */
- public static final int DEFAULT_THREAD_POOL_SIZE = 3;
- /** {@value} */
- public static final int DEFAULT_THREAD_PRIORITY = Thread.NORM_PRIORITY - 1;
- /** {@value} */
- public static final QueueProcessingType DEFAULT_TASK_PROCESSING_TYPE = QueueProcessingType.FIFO;
- private Context context;
- private int maxImageWidthForMemoryCache = 0;
- private int maxImageHeightForMemoryCache = 0;
- private int maxImageWidthForDiskCache = 0;
- private int maxImageHeightForDiskCache = 0;
- private BitmapProcessor processorForDiskCache = null;
- private Executor taskExecutor = null;
- private Executor taskExecutorForCachedImages = null;
- private boolean customExecutor = false;
- private boolean customExecutorForCachedImages = false;
- private int threadPoolSize = DEFAULT_THREAD_POOL_SIZE;
- private int threadPriority = DEFAULT_THREAD_PRIORITY;
- private boolean denyCacheImageMultipleSizesInMemory = false;
- private QueueProcessingType tasksProcessingType = DEFAULT_TASK_PROCESSING_TYPE;
- private int memoryCacheSize = 0;
- private long diskCacheSize = 0;
- private int diskCacheFileCount = 0;
- private MemoryCache memoryCache = null;
- private DiskCache diskCache = null;
- private FileNameGenerator diskCacheFileNameGenerator = null;
- private ImageDownloader downloader = null;
- private ImageDecoder decoder;
- private DisplayImageOptions defaultDisplayImageOptions = null;
- private boolean writeLogs = false;
- public Builder(Context context) {
- this.context = context.getApplicationContext();
- }
- /**
- * Sets options for memory cache
- *
- * @param maxImageWidthForMemoryCache Maximum image width which will be used for memory saving during decoding
- * an image to {@link android.graphics.Bitmap Bitmap}. <b>Default value - device's screen width</b>
- * @param maxImageHeightForMemoryCache Maximum image height which will be used for memory saving during decoding
- * an image to {@link android.graphics.Bitmap Bitmap}. <b>Default value</b> - device's screen height
- */
- public Builder memoryCacheExtraOptions(int maxImageWidthForMemoryCache, int maxImageHeightForMemoryCache) {
- this.maxImageWidthForMemoryCache = maxImageWidthForMemoryCache;
- this.maxImageHeightForMemoryCache = maxImageHeightForMemoryCache;
- return this;
- }
- /**
- * @deprecated Use
- * {@link #diskCacheExtraOptions(int, int, com.nostra13.universalimageloader.core.process.BitmapProcessor)}
- * instead
- */
- @Deprecated
- public Builder discCacheExtraOptions(int maxImageWidthForDiskCache, int maxImageHeightForDiskCache,
- BitmapProcessor processorForDiskCache) {
- return diskCacheExtraOptions(maxImageWidthForDiskCache, maxImageHeightForDiskCache, processorForDiskCache);
- }
- /**
- * Sets options for resizing/compressing of downloaded images before saving to disk cache.<br />
- * <b>NOTE: Use this option only when you have appropriate needs. It can make ImageLoader slower.</b>
- *
- * @param maxImageWidthForDiskCache Maximum width of downloaded images for saving at disk cache
- * @param maxImageHeightForDiskCache Maximum height of downloaded images for saving at disk cache
- * @param processorForDiskCache null-ok; {@linkplain BitmapProcessor Bitmap processor} which process images before saving them in disc cache
- */
- public Builder diskCacheExtraOptions(int maxImageWidthForDiskCache, int maxImageHeightForDiskCache,
- BitmapProcessor processorForDiskCache) {
- this.maxImageWidthForDiskCache = maxImageWidthForDiskCache;
- this.maxImageHeightForDiskCache = maxImageHeightForDiskCache;
- this.processorForDiskCache = processorForDiskCache;
- return this;
- }
- /**
- * Sets custom {@linkplain Executor executor} for tasks of loading and displaying images.<br />
- * <br />
- * <b>NOTE:</b> If you set custom executor then following configuration options will not be considered for this
- * executor:
- * <ul>
- * <li>{@link #threadPoolSize(int)}</li>
- * <li>{@link #threadPriority(int)}</li>
- * <li>{@link #tasksProcessingOrder(QueueProcessingType)}</li>
- * </ul>
- *
- * @see #taskExecutorForCachedImages(Executor)
- */
- public Builder taskExecutor(Executor executor) {
- if (threadPoolSize != DEFAULT_THREAD_POOL_SIZE || threadPriority != DEFAULT_THREAD_PRIORITY || tasksProcessingType != DEFAULT_TASK_PROCESSING_TYPE) {
- L.w(WARNING_OVERLAP_EXECUTOR);
- }
- this.taskExecutor = executor;
- return this;
- }
- /**
- * Sets custom {@linkplain Executor executor} for tasks of displaying <b>cached on disk</b> images (these tasks
- * are executed quickly so UIL prefer to use separate executor for them).<br />
- * <br />
- * If you set the same executor for {@linkplain #taskExecutor(Executor) general tasks} and
- * tasks about cached images (this method) then these tasks will be in the
- * same thread pool. So short-lived tasks can wait a long time for their turn.<br />
- * <br />
- * <b>NOTE:</b> If you set custom executor then following configuration options will not be considered for this
- * executor:
- * <ul>
- * <li>{@link #threadPoolSize(int)}</li>
- * <li>{@link #threadPriority(int)}</li>
- * <li>{@link #tasksProcessingOrder(QueueProcessingType)}</li>
- * </ul>
- *
- * @see #taskExecutor(Executor)
- */
- public Builder taskExecutorForCachedImages(Executor executorForCachedImages) {
- if (threadPoolSize != DEFAULT_THREAD_POOL_SIZE || threadPriority != DEFAULT_THREAD_PRIORITY || tasksProcessingType != DEFAULT_TASK_PROCESSING_TYPE) {
- L.w(WARNING_OVERLAP_EXECUTOR);
- }
- this.taskExecutorForCachedImages = executorForCachedImages;
- return this;
- }
- /**
- * Sets thread pool size for image display tasks.<br />
- * Default value - {@link #DEFAULT_THREAD_POOL_SIZE this}
- */
- public Builder threadPoolSize(int threadPoolSize) {
- if (taskExecutor != null || taskExecutorForCachedImages != null) {
- L.w(WARNING_OVERLAP_EXECUTOR);
- }
- this.threadPoolSize = threadPoolSize;
- return this;
- }
- /**
- * Sets the priority for image loading threads. Should be <b>NOT</b> greater than {@link Thread#MAX_PRIORITY} or
- * less than {@link Thread#MIN_PRIORITY}<br />
- * Default value - {@link #DEFAULT_THREAD_PRIORITY this}
- */
- public Builder threadPriority(int threadPriority) {
- if (taskExecutor != null || taskExecutorForCachedImages != null) {
- L.w(WARNING_OVERLAP_EXECUTOR);
- }
- if (threadPriority < Thread.MIN_PRIORITY) {
- this.threadPriority = Thread.MIN_PRIORITY;
- } else {
- if (threadPriority > Thread.MAX_PRIORITY) {
- this.threadPriority = Thread.MAX_PRIORITY;
- } else {
- this.threadPriority = threadPriority;
- }
- }
- return this;
- }
- /**
- * When you display an image in a small {@link android.widget.ImageView ImageView} and later you try to display
- * this image (from identical URI) in a larger {@link android.widget.ImageView ImageView} so decoded image of
- * bigger size will be cached in memory as a previous decoded image of smaller size.<br />
- * So <b>the default behavior is to allow to cache multiple sizes of one image in memory</b>. You can
- * <b>deny</b> it by calling <b>this</b> method: so when some image will be cached in memory then previous
- * cached size of this image (if it exists) will be removed from memory cache before.
- */
- public Builder denyCacheImageMultipleSizesInMemory() {
- this.denyCacheImageMultipleSizesInMemory = true;
- return this;
- }
- /**
- * Sets type of queue processing for tasks for loading and displaying images.<br />
- * Default value - {@link QueueProcessingType#FIFO}
- */
- public Builder tasksProcessingOrder(QueueProcessingType tasksProcessingType) {
- if (taskExecutor != null || taskExecutorForCachedImages != null) {
- L.w(WARNING_OVERLAP_EXECUTOR);
- }
- this.tasksProcessingType = tasksProcessingType;
- return this;
- }
- /**
- * Sets maximum memory cache size for {@link android.graphics.Bitmap bitmaps} (in bytes).<br />
- * Default value - 1/8 of available app memory.<br />
- * <b>NOTE:</b> If you use this method then
- * {@link com.nostra13.universalimageloader.cache.memory.impl.LruMemoryCache LruMemoryCache} will be used as
- * memory cache. You can use {@link #memoryCache(MemoryCache)} method to set your own implementation of
- * {@link MemoryCache}.
- */
- public Builder memoryCacheSize(int memoryCacheSize) {
- if (memoryCacheSize <= 0) throw new IllegalArgumentException("memoryCacheSize must be a positive number");
- if (memoryCache != null) {
- L.w(WARNING_OVERLAP_MEMORY_CACHE);
- }
- this.memoryCacheSize = memoryCacheSize;
- return this;
- }
- /**
- * Sets maximum memory cache size (in percent of available app memory) for {@link android.graphics.Bitmap
- * bitmaps}.<br />
- * Default value - 1/8 of available app memory.<br />
- * <b>NOTE:</b> If you use this method then
- * {@link com.nostra13.universalimageloader.cache.memory.impl.LruMemoryCache LruMemoryCache} will be used as
- * memory cache. You can use {@link #memoryCache(MemoryCache)} method to set your own implementation of
- * {@link MemoryCache}.
- */
- public Builder memoryCacheSizePercentage(int availableMemoryPercent) {
- if (availableMemoryPercent <= 0 || availableMemoryPercent >= 100) {
- throw new IllegalArgumentException("availableMemoryPercent must be in range (0 < % < 100)");
- }
- if (memoryCache != null) {
- L.w(WARNING_OVERLAP_MEMORY_CACHE);
- }
- long availableMemory = Runtime.getRuntime().maxMemory();
- memoryCacheSize = (int) (availableMemory * (availableMemoryPercent / 100f));
- return this;
- }
- /**
- * Sets memory cache for {@link android.graphics.Bitmap bitmaps}.<br />
- * Default value - {@link com.nostra13.universalimageloader.cache.memory.impl.LruMemoryCache LruMemoryCache}
- * with limited memory cache size (size = 1/8 of available app memory)<br />
- * <br />
- * <b>NOTE:</b> If you set custom memory cache then following configuration option will not be considered:
- * <ul>
- * <li>{@link #memoryCacheSize(int)}</li>
- * </ul>
- */
- public Builder memoryCache(MemoryCache memoryCache) {
- if (memoryCacheSize != 0) {
- L.w(WARNING_OVERLAP_MEMORY_CACHE);
- }
- this.memoryCache = memoryCache;
- return this;
- }
- /** @deprecated Use {@link #diskCacheSize(int)} instead */
- @Deprecated
- public Builder discCacheSize(int maxCacheSize) {
- return diskCacheSize(maxCacheSize);
- }
- /**
- * Sets maximum disk cache size for images (in bytes).<br />
- * By default: disk cache is unlimited.<br />
- * <b>NOTE:</b> If you use this method then
- * {@link com.nostra13.universalimageloader.cache.disc.impl.ext.LruDiscCache LruDiscCache}
- * will be used as disk cache. You can use {@link #diskCache(DiskCache)} method for introduction your own
- * implementation of {@link DiskCache}
- */
- public Builder diskCacheSize(int maxCacheSize) {
- if (maxCacheSize <= 0) throw new IllegalArgumentException("maxCacheSize must be a positive number");
- if (diskCache != null) {
- L.w(WARNING_OVERLAP_DISK_CACHE_PARAMS);
- }
- this.diskCacheSize = maxCacheSize;
- return this;
- }
- /** @deprecated Use {@link #diskCacheFileCount(int)} instead */
- @Deprecated
- public Builder discCacheFileCount(int maxFileCount) {
- return diskCacheFileCount(maxFileCount);
- }
- /**
- * Sets maximum file count in disk cache directory.<br />
- * By default: disk cache is unlimited.<br />
- * <b>NOTE:</b> If you use this method then
- * {@link com.nostra13.universalimageloader.cache.disc.impl.ext.LruDiscCache LruDiscCache}
- * will be used as disk cache. You can use {@link #diskCache(DiskCache)} method for introduction your own
- * implementation of {@link DiskCache}
- */
- public Builder diskCacheFileCount(int maxFileCount) {
- if (maxFileCount <= 0) throw new IllegalArgumentException("maxFileCount must be a positive number");
- if (diskCache != null) {
- L.w(WARNING_OVERLAP_DISK_CACHE_PARAMS);
- }
- this.diskCacheFileCount = maxFileCount;
- return this;
- }
- /** @deprecated Use {@link #diskCacheFileNameGenerator(com.nostra13.universalimageloader.cache.disc.naming.FileNameGenerator)} */
- @Deprecated
- public Builder discCacheFileNameGenerator(FileNameGenerator fileNameGenerator) {
- return diskCacheFileNameGenerator(fileNameGenerator);
- }
- /**
- * Sets name generator for files cached in disk cache.<br />
- * Default value -
- * {@link com.nostra13.universalimageloader.core.DefaultConfigurationFactory#createFileNameGenerator()
- * DefaultConfigurationFactory.createFileNameGenerator()}
- */
- public Builder diskCacheFileNameGenerator(FileNameGenerator fileNameGenerator) {
- if (diskCache != null) {
- L.w(WARNING_OVERLAP_DISK_CACHE_NAME_GENERATOR);
- }
- this.diskCacheFileNameGenerator = fileNameGenerator;
- return this;
- }
- /** @deprecated Use {@link #diskCache(com.nostra13.universalimageloader.cache.disc.DiskCache)} */
- @Deprecated
- public Builder discCache(DiskCache diskCache) {
- return diskCache(diskCache);
- }
- /**
- * Sets disk cache for images.<br />
- * Default value - {@link com.nostra13.universalimageloader.cache.disc.impl.UnlimitedDiscCache
- * BaseDiscCache}. Cache directory is defined by
- * {@link com.nostra13.universalimageloader.utils.StorageUtils#getCacheDirectory(Context)
- * StorageUtils.getCacheDirectory(Context)}.<br />
- * <br />
- * <b>NOTE:</b> If you set custom disk cache then following configuration option will not be considered:
- * <ul>
- * <li>{@link #diskCacheSize(int)}</li>
- * <li>{@link #diskCacheFileCount(int)}</li>
- * <li>{@link #diskCacheFileNameGenerator(FileNameGenerator)}</li>
- * </ul>
- */
- public Builder diskCache(DiskCache diskCache) {
- if (diskCacheSize > 0 || diskCacheFileCount > 0) {
- L.w(WARNING_OVERLAP_DISK_CACHE_PARAMS);
- }
- if (diskCacheFileNameGenerator != null) {
- L.w(WARNING_OVERLAP_DISK_CACHE_NAME_GENERATOR);
- }
- this.diskCache = diskCache;
- return this;
- }
- /**
- * Sets utility which will be responsible for downloading of image.<br />
- * Default value -
- * {@link com.nostra13.universalimageloader.core.DefaultConfigurationFactory#createImageDownloader(Context)
- * DefaultConfigurationFactory.createImageDownloader()}
- */
- public Builder imageDownloader(ImageDownloader imageDownloader) {
- this.downloader = imageDownloader;
- return this;
- }
- /**
- * Sets utility which will be responsible for decoding of image stream.<br />
- * Default value -
- * {@link com.nostra13.universalimageloader.core.DefaultConfigurationFactory#createImageDecoder(boolean)
- * DefaultConfigurationFactory.createImageDecoder()}
- */
- public Builder imageDecoder(ImageDecoder imageDecoder) {
- this.decoder = imageDecoder;
- return this;
- }
- /**
- * Sets default {@linkplain DisplayImageOptions display image options} for image displaying. These options will
- * be used for every {@linkplain ImageLoader#displayImage(String, android.widget.ImageView) image display call}
- * without passing custom {@linkplain DisplayImageOptions options}<br />
- * Default value - {@link DisplayImageOptions#createSimple() Simple options}
- */
- public Builder defaultDisplayImageOptions(DisplayImageOptions defaultDisplayImageOptions) {
- this.defaultDisplayImageOptions = defaultDisplayImageOptions;
- return this;
- }
- /**
- * Enables detail logging of {@link ImageLoader} work. To prevent detail logs don't call this method.
- * Consider {@link com.nostra13.universalimageloader.utils.L#disableLogging()} to disable
- * ImageLoader logging completely (even error logs)
- */
- public Builder writeDebugLogs() {
- this.writeLogs = true;
- return this;
- }
- /** Builds configured {@link ImageLoaderConfiguration} object */
- public ImageLoaderConfiguration build() {
- initEmptyFieldsWithDefaultValues();
- return new ImageLoaderConfiguration(this);
- }
- private void initEmptyFieldsWithDefaultValues() {
- if (taskExecutor == null) {
- taskExecutor = DefaultConfigurationFactory
- .createExecutor(threadPoolSize, threadPriority, tasksProcessingType);
- } else {
- customExecutor = true;
- }
- if (taskExecutorForCachedImages == null) {
- taskExecutorForCachedImages = DefaultConfigurationFactory
- .createExecutor(threadPoolSize, threadPriority, tasksProcessingType);
- } else {
- customExecutorForCachedImages = true;
- }
- if (diskCache == null) {
- if (diskCacheFileNameGenerator == null) {
- diskCacheFileNameGenerator = DefaultConfigurationFactory.createFileNameGenerator();
- }
- diskCache = DefaultConfigurationFactory
- .createDiskCache(context, diskCacheFileNameGenerator, diskCacheSize, diskCacheFileCount);
- }
- if (memoryCache == null) {
- memoryCache = DefaultConfigurationFactory.createMemoryCache(memoryCacheSize);
- }
- if (denyCacheImageMultipleSizesInMemory) {
- memoryCache = new FuzzyKeyMemoryCache(memoryCache, MemoryCacheUtils.createFuzzyKeyComparator());
- }
- if (downloader == null) {
- downloader = DefaultConfigurationFactory.createImageDownloader(context);
- }
- if (decoder == null) {
- decoder = DefaultConfigurationFactory.createImageDecoder(writeLogs);
- }
- if (defaultDisplayImageOptions == null) {
- defaultDisplayImageOptions = DisplayImageOptions.createSimple();
- }
- }
- }
- /**
- * Decorator. Prevents downloads from network (throws {@link IllegalStateException exception}).<br />
- * In most cases this downloader shouldn't be used directly.
- *
- * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
- * @since 1.8.0
- */
- private static class NetworkDeniedImageDownloader implements ImageDownloader {
- private final ImageDownloader wrappedDownloader;
- public NetworkDeniedImageDownloader(ImageDownloader wrappedDownloader) {
- this.wrappedDownloader = wrappedDownloader;
- }
- @Override
- public InputStream getStream(String imageUri, Object extra) throws IOException {
- switch (Scheme.ofUri(imageUri)) {
- case HTTP:
- case HTTPS:
- throw new IllegalStateException();
- default:
- return wrappedDownloader.getStream(imageUri, extra);
- }
- }
- }
- /**
- * Decorator. Handles <a href="http://code.google.com/p/android/issues/detail?id=6066">this problem</a> on slow networks
- * using {@link com.nostra13.universalimageloader.core.assist.FlushedInputStream}.
- *
- * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
- * @since 1.8.1
- */
- private static class SlowNetworkImageDownloader implements ImageDownloader {
- private final ImageDownloader wrappedDownloader;
- public SlowNetworkImageDownloader(ImageDownloader wrappedDownloader) {
- this.wrappedDownloader = wrappedDownloader;
- }
- @Override
- public InputStream getStream(String imageUri, Object extra) throws IOException {
- InputStream imageStream = wrappedDownloader.getStream(imageUri, extra);
- switch (Scheme.ofUri(imageUri)) {
- case HTTP:
- case HTTPS:
- return new FlushedInputStream(imageStream);
- default:
- return imageStream;
- }
- }
- }
- }
复制代码 Display Options每一个ImageLoader.displayImage(...)都可以使用Display Options。 - DisplayImageOptions options = new DisplayImageOptions.Builder()
- .showImageOnLoading(R.drawable.ic_stub) // resource or drawable
- .showImageForEmptyUri(R.drawable.ic_empty) // resource or drawable
- .showImageOnFail(R.drawable.ic_error) // resource or drawable
- .resetViewBeforeLoading(false) // default
- .delayBeforeLoading(1000)
- .cacheInMemory(false) // default
- .cacheOnDisk(false) // default
- .preProcessor(...)
- .postProcessor(...)
- .extraForDownloader(...)
- .considerExifParams(false) // default
- .imageScaleType(ImageScaleType.IN_SAMPLE_POWER_OF_2) // default
- .bitmapConfig(Bitmap.Config.ARGB_8888) // default
- .decodingOptions(...)
- .displayer(new SimpleBitmapDisplayer()) // default
- .handler(new Handler()) // default
- .build();
复制代码Display Options的主要职责就是记录相关的配置,它的内部其实就是一些字段的集合(如下面的源代码)。它有一个builder的内部类,这个类中的字段跟DisplayOption中的字段完全一致,它有一些默认值,通过修改builder可以配置DisplayOptions。
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