Glide 4.0由Google的各种团队内部使用，4.0被认为是内部稳定的。但外部用户可能会发现内部尚未发现的问题。因此，将此作为RC发布。如果没有发现稳定性或API中的重大问题，预计不久之后就会发布非RC版本。
一、集成
1、project gradle
repositories {
mavenLocal()
}
2、app gradle
compile 'com.android.support:support-v4:25.3.1' compile 'com.github.bumptech.glide:glide:4.0.0' annotationProcessor 'com.github.bumptech.glide:compiler:4.0.0'
3、混淆
#glide4.0
-keep public class * implements com.bumptech.glide.module.GlideModule
-keep public class * extends com.bumptech.glide.AppGlideModule
-keep public enum com.bumptech.glide.load.resource.bitmap.ImageHeaderParser$** {
**[] $VALUES;
public *;
}
# for DexGuard only
-keepresourcexmlelements manifest/application/meta-data@value=GlideModule
# 从glide4.0开始，GifDrawable没有提供getDecoder()方法，
# 需要通过反射获取gifDecoder字段值，所以需要保持GifFrameLoader和GifState类不被混淆
-keep class com.bumptech.glide.load.resource.gif.GifDrawable$GifState{*;}
-keep class com.bumptech.glide.load.resource.gif.GifFrameLoader {*;}
4、在4.0中不用像3.X需要在AndroidManifest.xml配置GlideModule，而是通过注解继承AppGlideModule的子类来配置。
@GlideModule
public class GlideConfiguration extends AppGlideModule {
@Override
public void applyOptions(Context context, GlideBuilder builder) {
//自定义缓存目录，磁盘缓存给150M 另外一种设置缓存方式
builder.setDiskCache(new InternalCacheDiskCacheFactory(context, "GlideImgCache", 150 * 1024 * 1024));
//配置图片缓存格式 默认格式为8888
builder.setDefaultRequestOptions(RequestOptions.formatOf(DecodeFormat.PREFER_ARGB_8888));
ViewTarget.setTagId(R.id.glide_tag_id);
}
/**
* 禁止解析Manifest文件
* 主要针对V3升级到v4的用户，可以提升初始化速度，避免一些潜在错误
* @return
*/
@Override
public boolean isManifestParsingEnabled() {
return false;
}
}
二、使用注意事项
1、使用GlideApp代替Glide，asBitmap、asGif、asDrawable、asFile都要放到load之前（glide3.7.0都是要在load之后调用）。
public static void loadImg(Context context,String url, ImageView imageView){
GlideApp.with(context)
.asBitmap()
.load(url)
.placeholder(R.drawable.placeholder) //设置资源加载过程中的占位符
.into(imageView);
}
2、占位符.placeholder(R.drawable.placeholder)不能用.9图，占位图片和加载的目标图片会同时显示，只是目标图片会先显示缩略图，然后显示正常。fallback和error还没测试过，有兴趣的可以测试看看。
3、加载gif图时，若调用dontAnimate()移除所有动画，gif就会加载失败。
4、计算gif播放一次的动画时长。
glide 3.7.0你可以这样获取动画时长：
public void loadGif(Context context,ImageView mIvGif,int url){
Glide.with(context)
.load(url)
.listener(new RequestListener() {
@Override
public boolean onException(Exception e, Integer model, Target target, boolean isFirstResource) {
return false;
}
@Override
public boolean onResourceReady(GlideDrawable resource, Integer model, Target target, boolean isFromMemoryCache, boolean isFirstResource) {
try {
int duration = 0;
GifDrawable gifDrawable = (GifDrawable) resource;
GifDecoder decoder = gifDrawable.getDecoder();
for (int i = 0; i < gifDrawable.getFrameCount(); i++) {
duration += decoder.getDelay(i);
}
Log.e("Glide3.7.0","gif播放一次动画时长duration:"+duration);
} catch (Throwable e) {
}
return false;
}
})
.into(new GlideDrawableImageViewTarget(mIvGif, 1));
}
glide4.0中GifDrawable没有提供getDecoder()方法并且还去掉了decoder这个成员变量。除此之外，glide4.0还去掉了GlideDrawableImageViewTarget类，那我们该如何来计算gif播放一次的时长呢？只能从源码中找答案了。
（1）寻找decoder
glide3.7.0 GifDrawable中我们可以发现decoder最终于会传入GifFrameLoader类中并赋值给gifDecoder变量。
//源码
//glide 3.7.0 GifDrawable.java
GifDrawable(GifState state) {
if (state == null) {
throw new NullPointerException("GifState must not be null");
}
this.state = state;
this.decoder = new GifDecoder(state.bitmapProvider);
this.paint = new Paint();
decoder.setData(state.gifHeader, state.data);
frameLoader = new GifFrameLoader(state.context, this, decoder, state.targetWidth, state.targetHeight);
frameLoader.setFrameTransformation(state.frameTransformation);
}
/*---------------------------------------------------------------------------------------------------*/
//glide 3.7.0 GifFrameLoader.java
private final GifDecoder gifDecoder;//私有属性
public GifFrameLoader(Context context, FrameCallback callback, GifDecoder gifDecoder, int width, int height) {
this(callback, gifDecoder, null,
getRequestBuilder(context, gifDecoder, width, height, Glide.get(context).getBitmapPool()));
}
GifFrameLoader(FrameCallback callback, GifDecoder gifDecoder, Handler handler,
GenericRequestBuilder requestBuilder) {
if (handler == null) {
handler = new Handler(Looper.getMainLooper(), new FrameLoaderCallback());
}
this.callback = callback;
//看这里
this.gifDecoder = gifDecoder;
this.handler = handler;
this.requestBuilder = requestBuilder;
}
glide4.0 GifDrawable类的构造中我们可以看到有一个gifDecoder的参数，这个参数的解释是解码器用于解码GIF数据（The decoder to use to decode GIF data）。继续看这个构造，发现gifDecoder最终也是被传到GifFrameLoader类中并赋值给gifDecoder变量。所以glide3.7.0中的decoder其实就是4.0中的gifDecoder。
//源码 //glide 4.0 GifDrawable.java private final GifState state; /* * @param gifDecoder The decoder to use to decode GIF data. * @param firstFrame The decoded and transformed first frame of this GIF. * @see #setFrameTransformation(com.bumptech.glide.load.Transformation, android.graphics.Bitmap) */ public GifDrawable(Context context, GifDecoder gifDecoder, BitmapPool bitmapPool, TransformationframeTransformation, int targetFrameWidth, int targetFrameHeight, Bitmap firstFrame) { this( new GifState( bitmapPool, new GifFrameLoader( // TODO(b/27524013): Factor out this call to Glide.get() Glide.get(context), gifDecoder, targetFrameWidth, targetFrameHeight, frameTransformation, firstFrame))); } /*---------------------------------------------------------------------------------------------*/ //glide4.0 GifFrameLoader.java private final GifDecoder gifDecoder;//私有属性 public GifFrameLoader( Glide glide, GifDecoder gifDecoder, int width, int height, Transformation transformation, Bitmap firstFrame) { this( glide.getBitmapPool(), Glide.with(glide.getContext()), gifDecoder, null /*handler*/, getRequestBuilder(Glide.with(glide.getContext()), width, height), transformation, firstFrame); } @SuppressWarnings("PMD.ConstructorCallsOverridableMethod") GifFrameLoader( BitmapPool bitmapPool, RequestManager requestManager, GifDecoder gifDecoder, Handler handler, RequestBuilder requestBuilder, Transformation transformation, Bitmap firstFrame) { this.requestManager = requestManager; if (handler == null) { handler = new Handler(Looper.getMainLooper(), new FrameLoaderCallback()); } this.bitmapPool = bitmapPool; this.handler = handler; this.requestBuilder = requestBuilder; //看这里 this.gifDecoder = gifDecoder; setFrameTransformation(transformation, firstFrame); }
（2）获取decoder
从上面Glide4.0的GifDrawable构造中可以看到gifDecoder被传递到GifFrameLoader中赋值给私有属性gifDecoder;，而GifFrameLoader又被传入GifState中并被赋值给它的成员变量frameLoader，那要怎么获取frameLoader？
从源码中，可以看到GifDrawable提供了getConstantState()方法来获取state变量（这个变量的类型就是GifState），但是GifState并没有get方法获取frameLoader，frameLoader对象中的gifDecoder也是私有，也没有提供get方法来获取，那么我们只能通过反射来获取了。
//源码
//glide4.0 GifDrawable.java
private final GifState state;
@Override
public ConstantState getConstantState() {
return state;
}
static class GifState extends ConstantState {
static final int GRAVITY = Gravity.FILL;
final BitmapPool bitmapPool;
final GifFrameLoader frameLoader;
public GifState(BitmapPool bitmapPool, GifFrameLoader frameLoader) {
this.bitmapPool = bitmapPool;
this.frameLoader = frameLoader;
}
@Override
public Drawable newDrawable(Resources res) {
return newDrawable();
}
@Override
public Drawable newDrawable() {
return new GifDrawable(this);
}
@Override
public int getChangingConfigurations() {
return 0;
}
}
通过反射来获取获取decoder
.listener(new RequestListener() { @Override public boolean onLoadFailed(@Nullable GlideException e, Object model, Target target, boolean isFirstResource) { return false; } @Override public boolean onResourceReady(GifDrawable gifDrawable, Object model, Target target, DataSource dataSource, boolean isFirstResource) { try { int duration = 0; // 计算动画时长 //GifDecoder decoder = gifDrawable.getDecoder();//4.0开始没有这个方法了 Drawable.ConstantState state = gifDrawable.getConstantState(); if(state!=null){ //不能混淆GifFrameLoader和GifState类 Object gifFrameLoader = getValue(state,"frameLoader"); if(gifFrameLoader!=null){ Object decoder = getValue(gifFrameLoader,"gifDecoder"); if(decoder!=null && decoder instanceof GifDecoder){ for (int i = 0; i < gifDrawable.getFrameCount(); i++) { duration += ((GifDecoder) decoder).getDelay(i); } } } Log.e("Glide4.0","gif播放动画时长duration:"+duration); } } catch (Throwable e) { } return false; } }) /*---------------------------------------------------------------------------------------------*/ /** * 通过字段名从对象或对象的父类中得到字段的值 * @param object 对象实例 * @param fieldName 字段名 * @return 字段对应的值 * @throws Exception */ public static Object getValue(Object object, String fieldName) throws Exception { if (object == null) { return null; } if (TextUtils.isEmpty(fieldName)) { return null; } Field field = null; Class clazz = object.getClass(); for (; clazz != Object.class; clazz = clazz.getSuperclass()) { try { field = clazz.getDeclaredField(fieldName); field.setAccessible(true); return field.get(object); } catch (Exception e) { //这里甚么都不要做！并且这里的异常必须这样写，不能抛出去。 //如果这里的异常打印或者往外抛，则就不会执行clazz = clazz.getSuperclass(),最后就不会进入到父类中了 } } return null; }
(3)设置gif循环播放次数
glide4.0中没有GlideDrawableImageViewTarget类，那么怎么设置循环播放次数呢？
从glide3.7.0源码可以发现GlideDrawableImageViewTarget是通过GlideDrawable的setLoopCount方法来设置循环播放次数的，查看setLoopCount具体实现地方是在GifDrawable，所以这里调用的其实是GifDrawable的setLoopCount方法。glide4.0中没有GlideDrawable类和GlideDrawableImageViewTarget类，但是仍然有GifDrawable类，并且onResourceReady方法中第一个参数就是GifDrawable，所以可以直接调用GifDrawable的setLoopCount(loopCount)来设置播放次数。
//源码
//3.7.0 GlideDrawableImageViewTarget.java
public GlideDrawableImageViewTarget(ImageView view, int maxLoopCount) {
super(view);
this.maxLoopCount = maxLoopCount;
}
@Override
public void onResourceReady(GlideDrawable resource, GlideAnimation animation) {
if (!resource.isAnimated()) {
//TODO: Try to generalize this to other sizes/shapes.
// This is a dirty hack that tries to make loading square thumbnails and then square full images less costly
// by forcing both the smaller thumb and the larger version to have exactly the same intrinsic dimensions.
// If a drawable is replaced in an ImageView by another drawable with different intrinsic dimensions,
// the ImageView requests a layout. Scrolling rapidly while replacing thumbs with larger images triggers
// lots of these calls and causes significant amounts of jank.
float viewRatio = view.getWidth() / (float) view.getHeight();
float drawableRatio = resource.getIntrinsicWidth() / (float) resource.getIntrinsicHeight();
if (Math.abs(viewRatio - 1f) <= SQUARE_RATIO_MARGIN
&& Math.abs(drawableRatio - 1f) <= SQUARE_RATIO_MARGIN) {
resource = new SquaringDrawable(resource, view.getWidth());
}
}
super.onResourceReady(resource, animation);
this.resource = resource;
//********看这里******
//android studio可以通过快捷键Ctrl+Alt+B查看其实现
resource.setLoopCount(maxLoopCount);
resource.start();
}
glide4.0 计算gif一次播放时长代码：
public static void loadGifImg(Context context,String url, ImageView imageView){
GlideApp.with(context)
.asGif()
.load(url)
.placeholder(R.drawable.placeholder)
.fallback(R.drawable.fallback)
.listener(new RequestListener() {
@Override
public boolean onLoadFailed(@Nullable GlideException e, Object model, Target target, boolean isFirstResource) {
return false;
}
@Override
public boolean onResourceReady(GifDrawable gifDrawable, Object model, Target target, DataSource dataSource, boolean isFirstResource) {
try {
//设置循环播放次数为1次
gifDrawable.setLoopCount(1);
// 计算动画时长
int duration = 0;
//GifDecoder decoder = gifDrawable.getDecoder();//4.0开始没有这个方法了
Drawable.ConstantState state = gifDrawable.getConstantState();
if(state!=null){
//不能混淆GifFrameLoader和GifState类
Object gifFrameLoader = getValue(state,"frameLoader");
if(gifFrameLoader!=null){
Object decoder = getValue(gifFrameLoader,"gifDecoder");
if(decoder!=null && decoder instanceof GifDecoder){
for (int i = 0; i < gifDrawable.getFrameCount(); i++) {
duration += ((GifDecoder) decoder).getDelay(i);
}
}
}
Log.e("Glide4.0","gif播放一次动画时长duration:"+duration);
}
} catch (Throwable e) {
}
return false;
}
})
.into(imageView);
}
注意：因为用了反射获取decoder，所以不能混淆GifFrameLoader和GifState类
5、设置淡入淡出动画
glide3.7.0
Glide.with(context)
.load(url)
.crossFade(100) //系统渐变动画
.placeholder(R.drawable.placeholder)
.fallback(R.drawable.fallback)
.diskCacheStrategy(DiskCacheStrategy.ALL)
.into(imageView);
glide4.0
GlideApp.with(context)
.load(url)
.transition(DrawableTransitionOptions.withCrossFade(100))//淡入淡出100m
.placeholder(R.drawable.placeholder)
.fallback(R.drawable.fallback)
.diskCacheStrategy(DiskCacheStrategy.ALL)
.into(imageView);
6、缓存策略
glide3.7.0
//DiskCacheStrategy.SOURCE：缓存原始数据 //DiskCacheStrategy.RESULT：缓存变换(如缩放、裁剪等)后的资源数据 //DiskCacheStrategy.NONE：什么都不缓存 //DiskCacheStrategy.ALL：缓存SOURC和RESULT //默认采用DiskCacheStrategy.RESULT策略，对于download only操作要使用DiskCacheStrategy.SOURCE
glide4.0
//DiskCacheStrategy.ALL 使用DATA和RESOURCE缓存远程数据，仅使用RESOURCE来缓存本地数据。 // DiskCacheStrategy.NONE 不使用磁盘缓存 // DiskCacheStrategy.DATA 在资源解码前就将原始数据写入磁盘缓存 // DiskCacheStrategy.RESOURCE 在资源解码后将数据写入磁盘缓存，即经过缩放等转换后的图片资源。 // DiskCacheStrategy.AUTOMATIC 根据原始图片数据和资源编码策略来自动选择磁盘缓存策略。 //默认采用DiskCacheStrategy.AUTOMATIC策略 /*-------------------------------------------------------------------------------*/ //源码 RequestOptions.java private DiskCacheStrategy diskCacheStrategy = DiskCacheStrategy.AUTOMATIC;
7、占位符、错误图片设置
glide4.0 若into中设置的是target，占位符（placeholder、error）需要在回调中再次设置，否则无效。
public static void loadImg(String url, ImageView imageView) {
//into中用Target，占位符（placeholder、error）需要在回调中设置
GlideApp.with(FanhuanApplication.getInstance().getApplication())
.asBitmap()
.load(url)
.placeholder(drawbleId) //设置资源加载过程中的占位符
.fallback(drawbleId)
.error(drawbleId)
.diskCacheStrategy(DiskCacheStrategy.ALL)
.into(new SimpleTarget() {
@Override
public void onResourceReady(Bitmap resource, Transition transition) {
imageView.setImageBitmap(resource);
}
@Override
public void onLoadFailed(@Nullable Drawable errorDrawable) {
super.onLoadFailed(errorDrawable);
if(errorDrawable!=null){
imageView.setImageDrawable(errorDrawable);
}
}
@Override
public void onLoadStarted(@Nullable Drawable placeholder) {
super.onLoadStarted(placeholder);
if(placeholder!=null){
imageView.setImageDrawable(placeholder);
}
}
});
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。