詳解Glide4.0集成及使用注意事項(xiàng)

更新時(shí)間：2018年08月31日 11:38:44 作者：lmz14

這篇文章主要介紹了詳解Glide4.0集成及使用注意事項(xiàng)，小編覺得挺不錯(cuò)的，現(xiàn)在分享給大家，也給大家做個(gè)參考。一起跟隨小編過來看看吧

Glide 4.0由Google的各種團(tuán)隊(duì)內(nèi)部使用，4.0被認(rèn)為是內(nèi)部穩(wěn)定的。但外部用戶可能會(huì)發(fā)現(xiàn)內(nèi)部尚未發(fā)現(xiàn)的問題。因此，將此作為RC發(fā)布。如果沒有發(fā)現(xiàn)穩(wěn)定性或API中的重大問題，預(yù)計(jì)不久之后就會(huì)發(fā)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

# 從glide4.0開始，GifDrawable沒有提供getDecoder()方法，
# 需要通過反射獲取gifDecoder字段值，所以需要保持GifFrameLoader和GifState類不被混淆
-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，而是通過注解繼承AppGlideModule的子類來配置。

@GlideModule
public class GlideConfiguration extends AppGlideModule {
  @Override
  public void applyOptions(Context context, GlideBuilder builder) {
    //自定義緩存目錄，磁盤緩存給150M 另外一種設(shè)置緩存方式
    builder.setDiskCache(new InternalCacheDiskCacheFactory(context, "GlideImgCache", 150 * 1024 * 1024));
    //配置圖片緩存格式 默認(rèn)格式為8888
    builder.setDefaultRequestOptions(RequestOptions.formatOf(DecodeFormat.PREFER_ARGB_8888));
    ViewTarget.setTagId(R.id.glide_tag_id);
  }

  /**
   * 禁止解析Manifest文件
   * 主要針對V3升級到v4的用戶，可以提升初始化速度，避免一些潛在錯(cuò)誤
   * @return
   */
  @Override
  public boolean isManifestParsingEnabled() {
    return false;
  }

}

二、使用注意事項(xiàng)

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之后調(diào)用）。

public static void loadImg(Context context,String url, ImageView imageView){
    GlideApp.with(context)
        .asBitmap()
        .load(url)
        .placeholder(R.drawable.placeholder) //設(shè)置資源加載過程中的占位符
        .into(imageView);
  }

2、占位符.placeholder(R.drawable.placeholder)不能用.9圖，占位圖片和加載的目標(biāo)圖片會(huì)同時(shí)顯示，只是目標(biāo)圖片會(huì)先顯示縮略圖，然后顯示正常。fallback和error還沒測試過，有興趣的可以測試看看。

3、加載gif圖時(shí)，若調(diào)用dontAnimate()移除所有動(dòng)畫，gif就會(huì)加載失敗。

4、計(jì)算gif播放一次的動(dòng)畫時(shí)長。

glide 3.7.0你可以這樣獲取動(dòng)畫時(shí)長：

 public void loadGif(Context context,ImageView mIvGif,int url){
    Glide.with(context)
        .load(url)
        .listener(new RequestListener<Integer, GlideDrawable>() {
          @Override
          public boolean onException(Exception e, Integer model, Target<GlideDrawable> target, boolean isFirstResource) {
            return false;
          }

          @Override
          public boolean onResourceReady(GlideDrawable resource, Integer model, Target<GlideDrawable> 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播放一次動(dòng)畫時(shí)長duration:"+duration);
            } catch (Throwable e) {
            }
            return false;
          }
        })
        .into(new GlideDrawableImageViewTarget(mIvGif, 1));
  }

glide4.0中GifDrawable沒有提供getDecoder()方法并且還去掉了decoder這個(gè)成員變量。除此之外，glide4.0還去掉了GlideDrawableImageViewTarget類，那我們該如何來計(jì)算gif播放一次的時(shí)長呢？只能從源碼中找答案了。

（1）尋找decoder

glide3.7.0 GifDrawable中我們可以發(fā)現(xiàn)decoder最終于會(huì)傳入GifFrameLoader類中并賦值給gifDecoder變量。

//源碼
//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;//私有屬性
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<GifDecoder, GifDecoder, Bitmap, Bitmap> requestBuilder) {
    if (handler == null) {
      handler = new Handler(Looper.getMainLooper(), new FrameLoaderCallback());
    }
    this.callback = callback;
    //看這里
    this.gifDecoder = gifDecoder;
    this.handler = handler;
    this.requestBuilder = requestBuilder;
  }

glide4.0 GifDrawable類的構(gòu)造中我們可以看到有一個(gè)gifDecoder的參數(shù)，這個(gè)參數(shù)的解釋是解碼器用于解碼GIF數(shù)據(jù)（The decoder to use to decode GIF data）。繼續(xù)看這個(gè)構(gòu)造，發(fā)現(xiàn)gifDecoder最終也是被傳到GifFrameLoader類中并賦值給gifDecoder變量。所以glide3.7.0中的decoder其實(shí)就是4.0中的gifDecoder。

//源碼
//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,
   Transformation<Bitmap> frameTransformation, 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;//私有屬性
 public GifFrameLoader(
   Glide glide,
   GifDecoder gifDecoder,
   int width,
   int height,
   Transformation<Bitmap> 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<Bitmap> requestBuilder,
   Transformation<Bitmap> 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;

  //看這里
  this.gifDecoder = gifDecoder;

  setFrameTransformation(transformation, firstFrame);
 }

（2）獲取decoder

從上面Glide4.0的GifDrawable構(gòu)造中可以看到gifDecoder被傳遞到GifFrameLoader中賦值給私有屬性gifDecoder;，而GifFrameLoader又被傳入GifState中并被賦值給它的成員變量frameLoader，那要怎么獲取frameLoader？

從源碼中，可以看到GifDrawable提供了getConstantState()方法來獲取state變量（這個(gè)變量的類型就是GifState），但是GifState并沒有g(shù)et方法獲取frameLoader，frameLoader對象中的gifDecoder也是私有，也沒有提供get方法來獲取，那么我們只能通過反射來獲取了。

//源碼
//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;
  }
 }

通過反射來獲取獲取decoder

.listener(new RequestListener<GifDrawable>() {
          @Override
          public boolean onLoadFailed(@Nullable GlideException e, Object model, Target<GifDrawable> target, boolean isFirstResource) {
            return false;
          }

          @Override
          public boolean onResourceReady(GifDrawable gifDrawable, Object model, Target<GifDrawable> target, DataSource dataSource, boolean isFirstResource) {
            try {
              int duration = 0;
              // 計(jì)算動(dòng)畫時(shí)長
              //GifDecoder decoder = gifDrawable.getDecoder();//4.0開始沒有這個(gè)方法了
              Drawable.ConstantState state = gifDrawable.getConstantState();
              if(state!=null){
                //不能混淆GifFrameLoader和GifState類
                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播放動(dòng)畫時(shí)長duration:"+duration);
              }
            } catch (Throwable e) {
            }
            return false;
          }
        })

/*---------------------------------------------------------------------------------------------*/
/**
   * 通過字段名從對象或?qū)ο蟮母割愔械玫阶侄蔚闹?
   * @param object 對象實(shí)例
   * @param fieldName 字段名
   * @return 字段對應(yīng)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) {
        //這里甚么都不要做！并且這里的異常必須這樣寫，不能拋出去。
        //如果這里的異常打印或者往外拋，則就不會(huì)執(zhí)行clazz = clazz.getSuperclass(),最后就不會(huì)進(jìn)入到父類中了
      }
    }

    return null;
  }

(3)設(shè)置gif循環(huán)播放次數(shù)

glide4.0中沒有GlideDrawableImageViewTarget類，那么怎么設(shè)置循環(huán)播放次數(shù)呢？

從glide3.7.0源碼可以發(fā)現(xiàn)GlideDrawableImageViewTarget是通過GlideDrawable的setLoopCount方法來設(shè)置循環(huán)播放次數(shù)的，查看setLoopCount具體實(shí)現(xiàn)地方是在GifDrawable，所以這里調(diào)用的其實(shí)是GifDrawable的setLoopCount方法。glide4.0中沒有GlideDrawable類和GlideDrawableImageViewTarget類，但是仍然有GifDrawable類，并且onResourceReady方法中第一個(gè)參數(shù)就是GifDrawable，所以可以直接調(diào)用GifDrawable的setLoopCount(loopCount)來設(shè)置播放次數(shù)。

//源碼
//3.7.0 GlideDrawableImageViewTarget.java
 public GlideDrawableImageViewTarget(ImageView view, int maxLoopCount) {
    super(view);
    this.maxLoopCount = maxLoopCount;
 }
  @Override
  public void onResourceReady(GlideDrawable resource, GlideAnimation<? super GlideDrawable> 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;
    //********看這里******
    //android studio可以通過快捷鍵Ctrl+Alt+B查看其實(shí)現(xiàn)
    resource.setLoopCount(maxLoopCount);
    resource.start();
  }

glide4.0 計(jì)算gif一次播放時(shí)長代碼：

  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<GifDrawable>() {
          @Override
          public boolean onLoadFailed(@Nullable GlideException e, Object model, Target<GifDrawable> target, boolean isFirstResource) {
            return false;
          }

          @Override
          public boolean onResourceReady(GifDrawable gifDrawable, Object model, Target<GifDrawable> target, DataSource dataSource, boolean isFirstResource) {
            try {
              //設(shè)置循環(huán)播放次數(shù)為1次
              gifDrawable.setLoopCount(1);
              // 計(jì)算動(dòng)畫時(shí)長
              int duration = 0;
              //GifDecoder decoder = gifDrawable.getDecoder();//4.0開始沒有這個(gè)方法了
              Drawable.ConstantState state = gifDrawable.getConstantState();
              if(state!=null){
                //不能混淆GifFrameLoader和GifState類
                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播放一次動(dòng)畫時(shí)長duration:"+duration);
              }
            } catch (Throwable e) {
            }
            return false;
          }
        })
        .into(imageView);
  }

注意：因?yàn)橛昧朔瓷浍@取decoder，所以不能混淆GifFrameLoader和GifState類

5、設(shè)置淡入淡出動(dòng)畫

glide3.7.0

Glide.with(context)
        .load(url)
        .crossFade(100) //系統(tǒng)漸變動(dòng)畫
        .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、緩存策略

glide3.7.0

//DiskCacheStrategy.SOURCE：緩存原始數(shù)據(jù)
//DiskCacheStrategy.RESULT：緩存變換(如縮放、裁剪等)后的資源數(shù)據(jù)
//DiskCacheStrategy.NONE：什么都不緩存
//DiskCacheStrategy.ALL：緩存SOURC和RESULT
//默認(rèn)采用DiskCacheStrategy.RESULT策略，對于download only操作要使用DiskCacheStrategy.SOURCE

glide4.0

//DiskCacheStrategy.ALL 使用DATA和RESOURCE緩存遠(yuǎn)程數(shù)據(jù)，僅使用RESOURCE來緩存本地?cái)?shù)據(jù)。
// DiskCacheStrategy.NONE 不使用磁盤緩存
// DiskCacheStrategy.DATA 在資源解碼前就將原始數(shù)據(jù)寫入磁盤緩存
// DiskCacheStrategy.RESOURCE 在資源解碼后將數(shù)據(jù)寫入磁盤緩存，即經(jīng)過縮放等轉(zhuǎn)換后的圖片資源。
// DiskCacheStrategy.AUTOMATIC 根據(jù)原始圖片數(shù)據(jù)和資源編碼策略來自動(dòng)選擇磁盤緩存策略。
//默認(rèn)采用DiskCacheStrategy.AUTOMATIC策略
/*-------------------------------------------------------------------------------*/
//源碼 RequestOptions.java
private DiskCacheStrategy diskCacheStrategy = DiskCacheStrategy.AUTOMATIC;

7、占位符、錯(cuò)誤圖片設(shè)置

glide4.0 若into中設(shè)置的是target，占位符（placeholder、error）需要在回調(diào)中再次設(shè)置，否則無效。

 public static void loadImg(String url, ImageView imageView) {
    //into中用Target，占位符（placeholder、error）需要在回調(diào)中設(shè)置
    GlideApp.with(FanhuanApplication.getInstance().getApplication())
        .asBitmap()
        .load(url)
        .placeholder(drawbleId) //設(shè)置資源加載過程中的占位符
        .fallback(drawbleId)
        .error(drawbleId)
        .diskCacheStrategy(DiskCacheStrategy.ALL)
        .into(new SimpleTarget<Bitmap>() {
          @Override
          public void onResourceReady(Bitmap resource, Transition<? super Bitmap> 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內(nèi)容，希望對大家的學(xué)習(xí)有所幫助，也希望大家多多支持腳本之家。

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