时间:2022-10-09 15:33:22 | 栏目:Android代码 | 点击:次
ImageLoader API 详细介绍,具体内容如下
在ImageLoader中有以下几个不同的构造器:
/** * 注意: 次构造器不支持下载进度提示功能 * @param context * @param withCache 是否支持缓存 * false--不带缓存 * true--支持缓存功能,默认缓存路径在外置存储缓冲目录中的picasso-big-cache文件夹中 */ public ImageLoader(Context context, boolean withCache) { this(context, null, withCache); } /** * 支持下载进度提示,以及设置缓存路径 * @param context * @param listener 下载进度监听器 * @param cachePath 缓存路径字符串 */ public ImageLoader(Context context, ProgressListener listener, String cachePath) { // TODO extend to support multiple libraries as Glide // TODO must be initialized and kept as an member instance to avoid losing cache Picasso.Builder builder = setupLoaderClientWithCachePath(context, listener, cachePath); setupListener(builder); picasso = builder.build(); picasso.setIndicatorsEnabled(BuildConfig.DEBUG); picasso.setLoggingEnabled(BuildConfig.DEBUG); } /** * 支持下载进度提示,以及设置缓存路径为默认路径picasso-big-cache * @param context * @param listener 下载进度监听器 * @param withCache 是否支持缓存 */ public ImageLoader(Context context, ProgressListener listener, boolean withCache) { // TODO extend to support multiple libraries as Glide // TODO must be initialized and kept as an member instance to avoid losing cache Picasso.Builder builder = setupLoaderClient(context, listener, withCache); setupListener(builder); picasso = builder.build(); picasso.setIndicatorsEnabled(BuildConfig.DEBUG); picasso.setLoggingEnabled(BuildConfig.DEBUG); }
public void shutdown() { if (picasso == null) return; Logger.d(Logger.TAG, "Image loader has been shutdown"); picasso.shutdown(); callback = null; }
将ImageLoader停止,一般在Activity停止,或者任务结束时调用此方法将其关闭
public ImageLoader cancelRequest(ImageView imageView) { picasso.cancelRequest(imageView); return this; }
取消之前显示到ImageView上的请求
public ImageLoader load(final int resourceId) { cleanResources(); this.imageResourceId = resourceId; return this; } public ImageLoader load(final String imageUri) { cleanResources(); this.imageUri = imageUri; return this; }
分别加载本地drawable文件夹下的图片,以及网络图片
public ImageLoader withPlaceholder(final int placeholder) { this.placeholder = placeholder; return this; }
设置ImageLoader下载图片时的预览图
public ImageLoader withErrorImage(final int errorImage) { this.errorImage = errorImage; return this; }
下载图片失败时显示的图片
public ImageLoader withTag(final String tag) { this.tag = tag; return this; } public void pause(final String tag) { if (picasso == null) return; picasso.pauseTag(tag); } public void resume(final String tag) { if (picasso == null) return; picasso.resumeTag(tag); }
以上三个方法依次是
1 下载图片时添加标签tag
2 暂停tag标签的下载任务
3 resume tag标签的下载任务
public ImageLoader withCallback(final Callback callback) { this.callback = callback; return this; }
给ImageLoader设置下载完成的回调,包含onSuccess和onFailed方法
public ImageLoader fit() { this.fit = true; return this; } public ImageLoader centerCrop() { this.centerCrop = true; return this; } public ImageLoader centerInside() { this.centerInside = true; return this; } public ImageLoader resize(final int widthResId, final int heightResId) { this.widthResId = widthResId; this.heigthResId = heightResId; return this; }
分别设置Picasso下载图片时的相应属性, 可以参考ImageView的scaleType属性
public void into(final ImageView imageView) { run(imageView); }
into方法调用内部run方法,并启动下载任务。 此方法需要在以上所有的API之后调用。
框架github地址: SimpleCommand框架