Glide生命周期管理
本文是Glide源碼解析系列的第一篇,通過這篇文檔躯枢,將可以了解到:
- 1.Glide如何綁定Activity库糠、Fragment生命周期。
- 2.Glide如何監(jiān)聽內(nèi)存變化氓奈、網(wǎng)絡(luò)變化。
- 3.Glide如何處理請(qǐng)求的生命周期鼎天。
1.0 生命周期相關(guān)UML類圖
2.0 生命周期綁定
Glide生命周期綁定是從入口單例類Glide開始的舀奶,通過with()多個(gè)重載方法來實(shí)現(xiàn)對(duì)生命周期的綁定工作。
public static RequestManager with(Fragment fragment)
public static RequestManager with(FragmentActivity activity)
public static RequestManager with(Activity activity)
public static RequestManager with(Context context)
以Activity的參數(shù)為例:
public static RequestManager with(Activity activity) {
RequestManagerRetriever retriever = RequestManagerRetriever.get();
return retriever.get(activity);
}
RequestManagerRetriever是一個(gè)單例類训措,可以理解為一個(gè)工廠類伪节,通過get方法接收不同的參數(shù),來創(chuàng)建RequestManager绩鸣。
public RequestManager get(Activity activity) {
if (Util.isOnBackgroundThread() || Build.VERSION.SDK_INT < Build.VERSION_CODES.HONEYCOMB) {
return get(activity.getApplicationContext());
} else {
assertNotDestroyed(activity);
android.app.FragmentManager fm = activity.getFragmentManager();
return fragmentGet(activity, fm);
}
}
public RequestManager get(android.app.Fragment fragment) {
if (fragment.getActivity() == null) {
throw new IllegalArgumentException("You cannot start a load on a fragment before it is attached");
}
if (Util.isOnBackgroundThread() || Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1) {
return get(fragment.getActivity().getApplicationContext());
} else {
android.app.FragmentManager fm = fragment.getChildFragmentManager();
return fragmentGet(fragment.getActivity(), fm);
}
}
如果是在子線程進(jìn)行的with操作怀大,那么Glide將默認(rèn)使用ApplicationContext,可以理解為不對(duì)請(qǐng)求的生命周期進(jìn)行管理呀闻,通過Activity拿到FragmentManager化借,并將創(chuàng)建RequestManager的任務(wù)傳遞下去。最終都走到了fragmentGet方法捡多,注意細(xì)微區(qū)別是Activity傳的參數(shù)的是Activity的FragmentManager蓖康,F(xiàn)ragment傳的參數(shù)的是ChildFragmentManager,這兩者不是一個(gè)東西垒手。
RequestManager fragmentGet(Context context, android.app.FragmentManager fm) {
//獲取RequestManagerFragment蒜焊,并獲取綁定到這個(gè)fragment的RequestManager
RequestManagerFragment current = getRequestManagerFragment(fm);
RequestManager requestManager = current.getRequestManager();
if (requestManager == null) {
//如果獲取RequestManagerFragment還沒有綁定過RequestManager,那么就創(chuàng)建RequestManager并綁定到RequestManagerFragment
requestManager = new RequestManager(context, current.getLifecycle(), current.getRequestManagerTreeNode());
current.setRequestManager(requestManager);
}
return requestManager;
}
2.0.1 創(chuàng)建RequestManagerFragment
這個(gè)方法創(chuàng)建了一個(gè)fragment科贬,并且創(chuàng)建并綁定了一個(gè)RequestManager泳梆,看看getRequestManagerFragment如何獲取的RequestManagerFragment。
RequestManagerFragment getRequestManagerFragment(final android.app.FragmentManager fm) {
//嘗試根據(jù)id去找到此前創(chuàng)建的RequestManagerFragment
RequestManagerFragment current = (RequestManagerFragment) fm.findFragmentByTag(FRAGMENT_TAG);
if (current == null) {
//如果沒有找到榜掌,那么從臨時(shí)存儲(chǔ)中尋找
current = pendingRequestManagerFragments.get(fm);
if (current == null) {
//如果仍然沒有找到优妙,那么新建一個(gè)RequestManagerFragment,并添加到臨時(shí)存儲(chǔ)中憎账。
//然后開啟事務(wù)綁定fragment并使用handler發(fā)送消息來將臨時(shí)存儲(chǔ)的fragment移除套硼。
current = new RequestManagerFragment();
pendingRequestManagerFragments.put(fm, current);
fm.beginTransaction().add(current, FRAGMENT_TAG).commitAllowingStateLoss();
handler.obtainMessage(ID_REMOVE_FRAGMENT_MANAGER, fm).sendToTarget();
}
}
return current;
}
這里有個(gè)問題,為什么需要使用pendingRequestManagerFragments這樣一個(gè)集合來臨時(shí)存儲(chǔ)一下fragment胞皱,然后又馬上通過handler發(fā)送消息移除邪意?這其實(shí)是跟主線程的Looper機(jī)制和Fragment的事務(wù)機(jī)制有關(guān)的。我們知道反砌,android中的主線程是一個(gè)閉環(huán)抄罕,通過Handler發(fā)送消息到MessageQueue,然后通過Looper輪詢獲取消息并交給Handler處理于颖。如下面一個(gè)常見場(chǎng)景:
Glide.with(this).load(url_1).into(mImageView_1);
Glide.with(this).load(url_2).into(mImageView_2);
這段代碼通過Glide加載了兩張圖片并設(shè)置到了兩個(gè)ImageView上呆贿,當(dāng)以上代碼塊執(zhí)行時(shí),其所屬的代碼群的Message剛剛從MessageQueue中取出正在被處理森渐,我們假設(shè)這個(gè)Message為m1做入,并且這個(gè)MessageQueue中沒有其他消息。此時(shí)情形是這樣的:
當(dāng)代碼執(zhí)行到getRequestManagerFragment這個(gè)方法時(shí)同衣,會(huì)通過開啟事務(wù)的方式來綁定這個(gè)fragment到activity竟块,相關(guān)源碼如下,這個(gè)方法在FragmentManagerImpl.java中:
public void enqueueAction(Runnable action, boolean allowStateLoss) {
if (!allowStateLoss) {
checkStateLoss();
}
synchronized (this) {
if (mDestroyed || mHost == null) {
throw new IllegalStateException("Activity has been destroyed");
}
if (mPendingActions == null) {
mPendingActions = new ArrayList<Runnable>();
}
mPendingActions.add(action);
if (mPendingActions.size() == 1) {
mHost.getHandler().removeCallbacks(mExecCommit);
mHost.getHandler().post(mExecCommit);
}
}
}
這里的mHost其實(shí)就是activity創(chuàng)建的耐齐,并且持有activity以及mMainHandler的引用浪秘,根據(jù)上述代碼可以知道蒋情,其實(shí)綁定fragment的操作最終是通過主線程的handler發(fā)送消息處理的,我們假設(shè)這個(gè)消息為m2耸携。然后handler.obtainMessage(ID_REMOVE_FRAGMENT_MANAGER, fm).sendToTarget();這句代碼發(fā)送的消息為m3棵癣。那么當(dāng)Glide.with(this).load(url_1).into(mImageView_1);這句代碼執(zhí)行這里時(shí),消息隊(duì)列有了變化:
但是m2這個(gè)消息并不會(huì)馬上被處理夺衍,這是因?yàn)閙1還有代碼還沒有執(zhí)行完畢隙券,也就是說這個(gè)fragment并不會(huì)馬上被綁定酵紫,此時(shí)m1繼續(xù)向下執(zhí)行到第二句代碼Glide.with(this).load(url_2).into(mImageView_2);當(dāng)這句代碼走到getRequestManagerFragment時(shí)爱葵,如果在m1時(shí)惠啄,我們不將fragment臨時(shí)存儲(chǔ)在pendingRequestManagerFragments中,由于m2還沒有被處理矛紫,那么
RequestManagerFragment current = (RequestManagerFragment) fm.findFragmentByTag(FRAGMENT_TAG);
必然是找不到這個(gè)fragment的赎瞎,那么就會(huì)導(dǎo)致重新創(chuàng)建一個(gè)新的重復(fù)的fragment,并開啟事務(wù)綁定颊咬,這顯然是不合情理的煎娇,因?yàn)镚lide需要保證rootFragment的唯一性,rootFragment即fragment依附或者沒有fragment依附的activity所創(chuàng)建的最上層RequestManagerFragment贪染。
接著往下看RequestManagerFragment的構(gòu)造方法做了什么缓呛。
public RequestManagerFragment() {
this(new ActivityFragmentLifecycle());
}
直接創(chuàng)建一個(gè)ActivityFragmentLifecycle,這個(gè)類實(shí)際是一個(gè)生命周期回調(diào)的管理類杭隙,實(shí)現(xiàn)了Lifecycle接口哟绊。所有的LifecycleListener會(huì)添加到一個(gè)集合中,當(dāng)RequestManagerFragment生命周期方法觸發(fā)時(shí)痰憎,會(huì)調(diào)用ActivityFragmentLifecycle相應(yīng)生命周期方法票髓,這個(gè)方法然后再遍歷調(diào)用所有LifecycleListener的生命周期方法,以onStart生命周期方法為例铣耘,RequestManagerFragment中:
public void onStart() {
super.onStart();
lifecycle.onStart();
}
然后ActivityFragmentLifecycle中:
void onStart() {
isStarted = true;
for (LifecycleListener lifecycleListener : Util.getSnapshot(lifecycleListeners)) {
lifecycleListener.onStart();
}
}
2.0.2 rootRequestManagerFragment
上面UML圖上洽沟,可以知道RequestManagerFragment還有一個(gè)rootRequestManagerFragment的成員變量,Glide每創(chuàng)建一個(gè)RequestManagerFragment蜗细,都會(huì)嘗試實(shí)例化rootRequestManagerFragment裆操,這個(gè)fragment即頂級(jí)的Activity所創(chuàng)建的RequestManagerFragment,相關(guān)代碼:
public void onAttach(Activity activity) {
super.onAttach(activity);
rootRequestManagerFragment = RequestManagerRetriever.get()
.getRequestManagerFragment(getActivity().getFragmentManager());
if (rootRequestManagerFragment != this) {
rootRequestManagerFragment.addChildRequestManagerFragment(this);
}
}
@Override
public void onDetach() {
super.onDetach();
if (rootRequestManagerFragment != null) {
rootRequestManagerFragment.removeChildRequestManagerFragment(this);
rootRequestManagerFragment = null;
}
}
可以看到炉媒,不管當(dāng)前的RequestManagerFragment是通過何種方式創(chuàng)建的踪区,都會(huì)在OnAttach時(shí),拿到當(dāng)前所綁定的Activity的FragmentManager來初始化一個(gè)RequestManagerFragment吊骤,這個(gè)RequestManagerFragment有可能是自身缎岗,有可能已經(jīng)被初始化過了,比如是通過with(Activity activity)的方式初始化的白粉,那么很顯然
RequestManagerRetriever.get().getRequestManagerFragment(getActivity().getFragmentManager());
這句代碼拿到的會(huì)是自己本身传泊,而如果是通過with(Fragment fragment)的形式創(chuàng)建的鼠渺,rootRequestManagerFragment將指向當(dāng)前fragment綁定到Activity所綁定的RequestManagerFragment,如果該Activity沒有綁定過眷细,那么會(huì)開啟事務(wù)綁定一個(gè)RequestManagerFragment拦盹。并且如果自己不是rootRequestManagerFragment的話,那么將會(huì)把自己保存到rootRequestManagerFragment中的一個(gè)集合:
private void addChildRequestManagerFragment(RequestManagerFragment child) {
childRequestManagerFragments.add(child);
}
簡(jiǎn)而言之薪鹦,Glide會(huì)為Activity創(chuàng)建一個(gè)RequestManagerFragment做為rootFragment掌敬,并保存該Activity底下所有Fragment(如果有的話)所創(chuàng)建的RequestManagerFragment惯豆。
2.0.3 RequestManagerTreeNode
RequestManagerFragment初始化時(shí)池磁,還會(huì)初始化RequestManagerTreeNode,顧名思義楷兽,這個(gè)類是用來保存請(qǐng)求樹節(jié)點(diǎn)的地熄,比如一個(gè)Activity采用Viewpager + Fragment的形式,而里面的Fragment又是一個(gè)ViewPager + Fragment的形式芯杀,這個(gè)時(shí)候端考,假設(shè)其中一個(gè)RequestManagerFragment生命周期方法走了,怎么知道哪些RequestManagerFragment綁定的LifeCycle應(yīng)該得到調(diào)用呢揭厚?理想的情況是却特,應(yīng)該讓綁定該RequestManagerFragment的Fragment所有的子Fragment的RequestManagerFragment的生命周期得到調(diào)用,比如如下場(chǎng)景中筛圆,Activity中各有兩個(gè)Fragment裂明,兩個(gè)Fragment又各有兩個(gè)子Fragment,在所有Fragment中太援,均通過with(this)的方式來加載圖片闽晦,經(jīng)過之前的分析我們可以知道的是,ROOT RMF 中會(huì)保存有6個(gè)RMF(RMF即RequestManagerFragment):
當(dāng)如果F1 RMF生命周期做出反應(yīng)時(shí)提岔,因?yàn)镽equestManagerFragment是無界面的仙蛉,所以可以理解為F1的生命周期做出反應(yīng)。我們希望F11和F12所綁定的RequestManagerFragment也要立即做出反應(yīng)碱蒙。但是F2以及其底下的RequestManagerFragment則不應(yīng)響應(yīng)對(duì)應(yīng)生命周期事件荠瘪,我們知道任何一個(gè)RequestManagerFragment可以通過rootRequestManagerFragment拿到這6個(gè)RMF,繼而拿到其所對(duì)應(yīng)的RequestManager赛惩,那么怎么去確定F11 RMF 和 F12 RMF呢巧还?這就是RequestManagerTreeNode干的事情了,RequestManagerFragment中的非靜態(tài)內(nèi)部類FragmentRequestManagerTreeNode實(shí)現(xiàn)了RequestManagerTreeNode:
private class FragmentRequestManagerTreeNode implements RequestManagerTreeNode {
@Override
public Set<RequestManager> getDescendants() {
Set<RequestManagerFragment> descendantFragments = getDescendantRequestManagerFragments();
HashSet<RequestManager> descendants =
new HashSet<RequestManager>(descendantFragments.size());
for (RequestManagerFragment fragment : descendantFragments) {
if (fragment.getRequestManager() != null) {
descendants.add(fragment.getRequestManager());
}
}
return descendants;
}
}
這個(gè)類做的事情比較簡(jiǎn)單坊秸,調(diào)用外部類RequestManagerFragment的方法getDescendantRequestManagerFragments拿到所有的“后裔”Fragment,然后再取出它的RequestManager麸祷,然后集合裝起來返回,這里的后裔在前面的例子中褒搔,指的就是F11 RMF 和 F12 RMF阶牍,看看getDescendantRequestManagerFragments是怎么拿到的F11和F12:
@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1)
public Set<RequestManagerFragment> getDescendantRequestManagerFragments() {
//如果自己是rootFragment喷面,那么直接返回childRequestManagerFragments
if (rootRequestManagerFragment == this) {
return Collections.unmodifiableSet(childRequestManagerFragments);
} else if (rootRequestManagerFragment == null || Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR1) {
// Pre JB MR1 doesn't allow us to get the parent fragment so we can't introspect hierarchy, so just
// return an empty set.
return Collections.emptySet();
} else {
HashSet<RequestManagerFragment> descendants = new HashSet<RequestManagerFragment>();
for (RequestManagerFragment fragment
//遍歷取出rootFragment中的RMF,并獲取到其parentFragment走孽,找出后裔惧辈。
: rootRequestManagerFragment.getDescendantRequestManagerFragments()) {
if (isDescendant(fragment.getParentFragment())) {
descendants.add(fragment);
}
}
return Collections.unmodifiableSet(descendants);
}
}
看看isDescendant方法是如何判斷的:
private boolean isDescendant(Fragment fragment) {
Fragment root = this.getParentFragment();
while (fragment.getParentFragment() != null) {
if (fragment.getParentFragment() == root) {
return true;
}
fragment = fragment.getParentFragment();
}
return false;
}
依上面的例子,當(dāng)遍歷到F11 RMF時(shí)磕瓷,參數(shù)傳遞過來的是F11盒齿,root 則為F1,F(xiàn)11再拿到parent困食,也是F1边翁,返回true,F(xiàn)12 RMF類似也返回true硕盹;
當(dāng)遍歷到F21 RMF時(shí)符匾,參數(shù)傳入F21,root仍是F1瘩例,此時(shí)F21再怎么拿Parent也不可能是root,返回false啊胶。
簡(jiǎn)而言之,RequestManagerTreeNode用來獲取綁定該RequestManagerFragment的Fragment的所有子Fragment所綁定的RequestManagerFragment所綁定的RequestManager
2.0.4 RequestManager
上面一直在說RequestManagerFragment垛贤,下面回到FragmentGet方法中焰坪,再貼一次,免得上翻麻煩:
RequestManager fragmentGet(Context context, android.app.FragmentManager fm) {
//獲取RequestManagerFragment聘惦,并獲取綁定到這個(gè)fragment的RequestManager
RequestManagerFragment current = getRequestManagerFragment(fm);
RequestManager requestManager = current.getRequestManager();
if (requestManager == null) {
//如果獲取RequestManagerFragment還沒有綁定過RequestManager某饰,那么就創(chuàng)建RequestManager并綁定到RequestManagerFragment
requestManager = new RequestManager(context, current.getLifecycle(), current.getRequestManagerTreeNode());
current.setRequestManager(requestManager);
}
return requestManager;
}
根據(jù)上面的UML圖,可以知道RequestManager是一個(gè)非常核心的類部凑,并且還實(shí)現(xiàn)了LifecycleListener來處理請(qǐng)求的生命周期露乏。上述代碼在創(chuàng)建RequestManager時(shí),傳遞了3個(gè)參數(shù)涂邀,分別是context瘟仿,前面分析過的初始化RequestManagerFragment所創(chuàng)建的LifeCycle和RequestManagerTreeNode。直接看RequestManager的構(gòu)造函數(shù):
public RequestManager(Context context, Lifecycle lifecycle, RequestManagerTreeNode treeNode) {
this(context, lifecycle, treeNode, new RequestTracker(), new ConnectivityMonitorFactory());
}
調(diào)用的另一個(gè)構(gòu)造方法比勉,并增加了兩個(gè)新的參數(shù)RequestTracker和ConnectivityMonitorFactory劳较。
RequestManager(Context context, final Lifecycle lifecycle, RequestManagerTreeNode treeNode,
RequestTracker requestTracker, ConnectivityMonitorFactory factory) {
this.context = context.getApplicationContext();
this.lifecycle = lifecycle;
this.treeNode = treeNode;
this.requestTracker = requestTracker;
this.glide = Glide.get(context);
this.optionsApplier = new OptionsApplier();
ConnectivityMonitor connectivityMonitor = factory.build(context,
new RequestManagerConnectivityListener(requestTracker));
// If we're the application level request manager, we may be created on a background thread. In that case we
// cannot risk synchronously pausing or resuming requests, so we hack around the issue by delaying adding
// ourselves as a lifecycle listener by posting to the main thread. This should be entirely safe.
if (Util.isOnBackgroundThread()) {
new Handler(Looper.getMainLooper()).post(new Runnable() {
@Override
public void run() {
lifecycle.addListener(RequestManager.this);
}
});
} else {
lifecycle.addListener(this);
}
lifecycle.addListener(connectivityMonitor);
}
RequestTracker即所有請(qǐng)求操作的真正處理者,所有Request的暫停取消執(zhí)行操作都由RequestTracker來完成浩聋,如RequestManager暫停請(qǐng)求的實(shí)現(xiàn):
public void pauseRequests() {
Util.assertMainThread();
requestTracker.pauseRequests();
}
2.0.5 網(wǎng)絡(luò)狀態(tài)監(jiān)測(cè)
請(qǐng)求生命周期的實(shí)現(xiàn)細(xì)節(jié)后面再說观蜗,暫時(shí)埋坑,先來看看ConnectivityMonitorFactory這個(gè)工廠生產(chǎn)了什么衣洁。
public class ConnectivityMonitorFactory {
public ConnectivityMonitor build(Context context, ConnectivityMonitor.ConnectivityListener listener) {
final int res = context.checkCallingOrSelfPermission("android.permission.ACCESS_NETWORK_STATE");
final boolean hasPermission = res == PackageManager.PERMISSION_GRANTED;
if (hasPermission) {
return new DefaultConnectivityMonitor(context, listener);
} else {
return new NullConnectivityMonitor();
}
}
}
很簡(jiǎn)單墓捻,接收一個(gè)ConnectivityListener根據(jù)是否有監(jiān)控網(wǎng)絡(luò)狀態(tài)的權(quán)限來創(chuàng)建相應(yīng)的網(wǎng)絡(luò)監(jiān)控器。
DefaultConnectivityMonitor也比較簡(jiǎn)單坊夫,就是內(nèi)部定義了一個(gè)廣播接收者砖第,并且也實(shí)現(xiàn)了lifeCycleListener撤卢。在上面RequestManager的構(gòu)造方法中,創(chuàng)建了一個(gè)RequestManagerConnectivityListener:
private static class RequestManagerConnectivityListener implements ConnectivityMonitor.ConnectivityListener {
private final RequestTracker requestTracker;
public RequestManagerConnectivityListener(RequestTracker requestTracker) {
this.requestTracker = requestTracker;
}
@Override
public void onConnectivityChanged(boolean isConnected) {
if (isConnected) {
requestTracker.restartRequests();
}
}
}
這個(gè)listener很簡(jiǎn)單梧兼,收到網(wǎng)絡(luò)狀態(tài)連接就重啟請(qǐng)求放吩。然后通過工廠創(chuàng)建出了DefaultConnectivityMonitor,并把它添加到了lifecycle中羽杰。到這里渡紫,Glide監(jiān)測(cè)網(wǎng)絡(luò)狀態(tài)來重啟請(qǐng)求的實(shí)現(xiàn)方式就呼之欲出了,大體步驟如下:
在相應(yīng)的生命周期方法中考赛,會(huì)調(diào)用lifecycle的生命周期方法惕澎,lifecycle會(huì)調(diào)用DefaultConnectivityMonitor所實(shí)現(xiàn)的相應(yīng)生命周期方法來注冊(cè)及解除注冊(cè)網(wǎng)絡(luò)狀態(tài)的廣播接收者,收到廣播后欲虚,會(huì)回調(diào)之前傳遞的參數(shù)ConnectivityListener的onConnectivityChanged方法來處理Request集灌。
2.0.6 內(nèi)存狀態(tài)監(jiān)測(cè)
RequestManager中還存有Glide這個(gè)入口類的實(shí)例悔雹,構(gòu)造方法中直接獲取到的复哆,用來對(duì)內(nèi)存狀態(tài)的變更作出處理,比較簡(jiǎn)單腌零,看看流程便可以了梯找,以onTrimMemory為例,
當(dāng)RequestManagerFragment的onTrimMemory被調(diào)用時(shí),會(huì)調(diào)用其綁定的RequetManager的相應(yīng)方法來處理:
@Override
public void onTrimMemory(int level) {
// If an activity is re-created, onTrimMemory may be called before a manager is ever set.
// See #329.
if (requestManager != null) {
requestManager.onTrimMemory(level);
}
}
然后RequestManager再調(diào)用Glide入口類的trimMemory來釋放更多內(nèi)存:
public void onTrimMemory(int level) {
glide.trimMemory(level);
}
2.0.7 生命周期回調(diào)流程總結(jié)
在RequestManager構(gòu)造方法中益涧,還會(huì)將自身添加到LifeCycle中锈锤,這樣,整個(gè)流程就暢通了:
細(xì)心的可以發(fā)現(xiàn)闲询,雖然在構(gòu)造RequestManager時(shí)傳遞了參數(shù)RequestManagerTreeNode久免,但是在這個(gè)回調(diào)流程中,并沒有對(duì)所有后裔RMF的RequestManager進(jìn)行調(diào)用扭弧,Glide默認(rèn)確實(shí)是不會(huì)去調(diào)用阎姥,但這里并不意味著這些RequestManager不會(huì)被調(diào)用到,事實(shí)上鸽捻,當(dāng)前RMF生命周期被調(diào)用時(shí)呼巴,就意味后裔Fragment生命周期也會(huì)被調(diào)用,那么后裔Fragment這個(gè)流程仍然會(huì)走一遍御蒲,那么RequestManagerTreeNode到底有什么用呢?答案是沒用衣赶,完全沒用,如果只是簡(jiǎn)單使用Glide的話厚满。當(dāng)然府瞄,RequestManager暴露了相關(guān)接口給開發(fā)者使用:
public void resumeRequestsRecursive() {
Util.assertMainThread();
resumeRequests();
for (RequestManager requestManager : treeNode.getDescendants()) {
requestManager.resumeRequests();
}
}
調(diào)用這個(gè)方法將會(huì)把所有后裔的請(qǐng)求同時(shí)一起處理。
本文轉(zhuǎn)自作者“他的大姨父”的Glide生命周期管理專題碘箍,如有侵權(quán)遵馆,請(qǐng)聯(lián)系作者效效進(jìn)行修改续崖,聯(lián)系方式在本簡(jiǎn)書的聲明中哦~~