![\"\"](\"\/wp-content\/uploads\/2017\/12\/WX20171205-004809@2x-1024x82.png\")
<\/p>\n\u5411\u6765\u89c9\u5f97\u7535\u8bdd\u9762\u8bd5\u5c31\u89c9\u5f97\u80af\u5b9a\u9ec4\uff0c\u603b\u6709\u4e00\u79cd\u5c40\u4fc3\u548c\u4e0d\u5b89\uff0c\u4eca\u5929\u63a5\u5230\u963f\u91cc\u7684\u7535\u8bdd\u9762\uff0c\u5f53\u65f6\u5728\u5bb6\u91cc\u3002\u95ee\u7684\u95ee\u9898\u8fd8\u662f\u90a3\u51e0\u4e2a\u8001\u751f\u5e38\u8c08\u7684\u95ee\u9898\u3002 view \u7684\u7ed8\u5236\u554a\uff0c handler \u673a\u5236\u554a\uff0chashmap\u5b9e\u73b0\u539f\u7406\u554a\u3002\u6548\u7387\u554a\uff0c\u4f18\u5316\u554a\u5565\u7684\u3002<\/p>\n
\u4eca\u5929\u53ef\u8c13\u662f\u90fd\u78b0\u4e0a\u4e86\uff08\u5176\u5b9e\u8fd8\u5dee\u90a3\u4e2aasyntask \u554a http\u534f\u8bae\u554a \u591a\u7ebf\u7a0b\u540c\u6b65\u554a\uff0cjvm \u554a\uff0c\u542f\u52a8\u6d41\u7a0b\u554a\u5df4\u62c9\u5df4\u62c9\uff09\uff0c\u8fd9\u4e00\u5173\u4e0d\u8fc7\uff0c\u4e0b\u4e00\u5173\u5c31\u6ca1\u95e8\u554a\uff0c\u5176\u5b9e\u8fd9\u4e2a\u548c\u9879\u76ee\u7ecf\u9a8c\u6216\u8005\u4e00\u4e2a\u4eba\u80fd\u4e0d\u80fd\u505a\u6210\u4e8b\u60c5\u5e76\u6ca1\u6709\u592a\u5927\u5173\u7cfb\uff0c\u6700\u9ad8\u7684\u667a\u5546\u662f\u628a\u4e8b\u505a\u6210\uff0c\u6700\u9ad8\u7684\u60c5\u5546\u662f\u9760\u8c31\u3002<\/p>\n
\u4ee5\u524d\u5de5\u4f5c\u6ca1\u90a3\u4e48\u591a\u95f2\u60c5\u770b\u8fd9\u4e2a\uff0c\u90a3\u4eca\u5929\u5c31\u5e26\u7740\u9762\u8bd5\u7684\u76ee\u7684\u6765\u5f7b\u5e95\u7814\u7a76\u4e00\u4e0b \u9762\u8bd5\u7b2c\u4e00\u9898 Handler\u673a\u5236\u3002<\/p>\n
\u4ece\u5e94\u7528\u5f00\u53d1\u8fd9\u4e2a\u89d2\u5ea6\u6765\u770b\uff0c\u5927\u5bb6\u53ef\u80fd\u90fd\u77e5\u9053 \u4e0d\u80fd\u5728\u5b50\u7ebf\u7a0b\u4e2d\u76f4\u63a5new \u4e00\u4e2ahander\u3002\u5426\u5219\u4f1a\u629b\u51fa\u5e38\u89c1\u7684<\/p>\n
[code lang=text]
\njava.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()
\n[\/code]<\/p>\n
\u7136\u540e\u5927\u5bb6\u4e5f\u77e5\u9053(\u4e0a\u9762\u660e\u663e\u63d0\u793a)\uff0c\u5728\u5b50\u7ebf\u7a0b\u4e2d\u5047\u5982\u8981\u521b\u5efahandler \u53ef\u4ee5\u5148Looper.prepare()\u7136\u540e\u5c31\u53ef\u4ee5\u521b\u5efa\u4e86\u3002<\/p>\n
\u6211\u4eec\u5199\u4e00\u4e2a\u5e38\u89c1\u7684\u7528handler \u8fdb\u884c\u7ebf\u7a0b\u95f4\u901a\u8baf\u4f8b\u5b50\uff0c\u5b50\u7ebf\u7a0b\u53d1\u9001\u6d88\u606f\u7ed9\u4e3b\u7ebf\u7a0b\u66f4\u65b0UI
\n<\/p>\n
[code lang=java]
\n mHandler = new Handler() {
\n @Override
\n public void dispatchMessage(Message msg) {
\n super.dispatchMessage(msg);
\n Log.d(TAG, msg.what + " I am in "+Thread.currentThread());
\n }
\n };<\/p>\n
Thread thread = new Thread(new Runnable() {
\n @Override
\n public void run() {
\n try {
\n Thread.sleep(1000);
\n } catch (InterruptedException e) {
\n e.printStackTrace();
\n }
\n mHandler.sendEmptyMessage(100);<\/p>\n
}
\n });
\n thread.start();<\/p>\n
[\/code]<\/p>\n
<\/p>\n
\u6211\u4eec\u4ee5\u8fd9\u4e2a\u4f8b\u5b50\u4e3a\u5165\u53e3 \u6765\u770b\u770b\u8d70\u4e86\u54ea\u4e9b\u6d41\u7a0b<\/p>\n
\u9996\u5148\u6211\u5728\u4e3b\u7ebf\u7a0b\u4e2d\u521b\u5efa\u4e86\u65e0\u53c2\u6570\u7684handler,\u6211\u4eec\u8fdb\u5165handler\u6784\u9020\u51fd\u6570 \u770b\u770b\u91cc\u9762\u6709\u4ec0\u4e48<\/p>\n
[code lang=java]
\npublic Handler(Callback callback, boolean async) {
\n (\u53ea\u5217\u51fa\u4e86\u5173\u952e\u4ee3\u7801)
\n mLooper = Looper.myLooper();
\n if (mLooper == null) {
\n throw new RuntimeException(
\n "Can't create handler inside thread that has not called Looper.prepare()");
\n }
\n mQueue = mLooper.mQueue;
\n }<\/p>\n
[\/code]<\/p>\n
\u53ef\u4ee5\u770b\u5230 Handler \u7684\u8fd9\u4e2a\u6784\u9020\u51fd\u6570\u521d\u59cb\u5316\u4e86\u4e24\u4e2a\u6210\u5458\u53d8\u91cf mLooper \u548cmQueue\u3002 \u6211\u4eec\u53d1\u73b0\u7b2c\u4e8c\u4e2a\u6210\u5458\u53d8\u91cf mQueue\u76f4\u63a5\u4ece\u7b2c\u4e00\u4e2a\u6210\u5458\u53d8\u91cf\u4e2d\u83b7\u53d6\u7684\uff0c\u56e0\u6b64\u4e0d\u5173\u5fc3\u5b83\u3002\u53ea\u9700\u77e5\u9053 Handler \u4e2d\u6709\u4e00\u4e2a Looper \u7684\u5b9e\u4f8b<\/b>\u8fd9\u5f88\u91cd\u8981 \u52a0\u7c97 \uff0c\u8fd9\u5c31\u5f15\u51fa\u4e86\u7b2c\u4e8c\u4e2a\u4e3b\u89d2 Looper \uff0c\u90a3\u8fd9\u4e2amyLooper()\u662f\u4e2a\u5565\u73a9\u610f\uff1f \u70b9\u8fdb\u53bb\u770b\u770b\u3002<\/p>\n
[code lang=java]
\n public static @Nullable Looper myLooper() {
\n return sThreadLocal.get();
\n }
\n[\/code]<\/p>\n
\u55ef\u770b\u4f3c\u5f88\u7b80\u5355\uff0c\u662f\u4eceLooper \u7c7b\u4e2d\u4e00\u4e2a\u9759\u6001\u53d8\u91cf\u4e2d\u53d6\u51fa\u4e86\u4e00\u4e2a\u5b9e\u4f8b\uff0c\u770b\u540d\u5b57\u662f\u4e00\u4e2a\u548c\u4ec0\u4e48\u7ebf\u7a0b\u76f8\u5173\u7684\u4e1c\u897f\u3002\u65e2\u7136\u4e00\u5f00\u59cb\u7528\u5230\u4e86get \u5c31\u4e00\u5b9a\u662f\u5728\u67d0\u4e2a\u5730\u65b9\u8fdb\u884c\u4e86set\u4e86\u4f60\u8bf4\u4e0d\u662f\u5417\uff0c\u5426\u5219\u5e94\u8be5\u662f\u7a7a\u554a\uff0c\u6211\u518d\u627e\u627e\u3002\u76f4\u5230\u627e\u5230\u4e86\u8fd9\u91cc<\/p>\n
[code lang=java]
\n private static void prepare(boolean quitAllowed) {
\n if (sThreadLocal.get() != null) {
\n throw new RuntimeException("Only one Looper may be created per thread");
\n }
\n sThreadLocal.set(new Looper(quitAllowed));
\n }
\n[\/code]<\/p>\n
\u660e\u767d\u4e86\u5427 \u6240\u4ee5\u8bf4 \u5f97\u5148prepare \u4e00\u4e0b\u3002\u628a\u4e00\u4e2aLooper \u7684\u5b9e\u4f8b\u4f20\u9012\u7ed9\u4e00\u4e2a\u9759\u6001sThreadLocal \u4fdd\u5b58\u8d77\u6765\uff0c\u90a3\u4e3a\u4ec0\u4e48\u4e3b\u7ebf\u7a0b\u53ef\u4ee5\u76f4\u63a5new Handler \u5462\uff1f
\n\u5176\u5b9e \u5728ActivityThread.java \u7684main \u65b9\u6cd5\u4e2d \u8c03\u7528\u4e86\u8fd9\u4e2aLooper.prepareMainLooper(); \u95f4\u63a5\u518d\u8c03\u7528\u4e86prepare\u65b9\u6cd5\u3002\u56e0\u6b64\u6211\u4eec\u4e0d\u9700\u8981\u518d\u4e3b\u52a8\u8c03\u7528Looper.prepare\u5566. \u8c03\u7528\u4e86\u53cd\u800c\u4f1a\u62a5\u9519
\nHandler \u7684\u6784\u9020\uff08new\uff09 \u6211\u4eec\u5c31\u5206\u6790\u5230\u8fd9\u91cc\uff0c\u518d\u6765\u770b \u5b9e\u4f8b \uff0c\u4e0a\u9762\u5728\u6211\u4eec\u81ea\u5df1\u7684\u4f8b\u5b50\u4e2d\u6211\u4eec\u7528 mHandler.sendMessage\u4e86\uff0c
\n\u6211\u4eec\u5148\u6765\u770b\u770bMessage\u662f\u4e2asen\u9b54\u3002
\n\u8ddf\u8e2a\u4ee3\u7801\u53d1\u73b0\u6211\u4eec sendEmptyMessage \u4e8b\u5b9e\u4e0a\u8c03\u7528\u7684\u662f sendEmptyMessageDelayed(what, 0)->sendMessageDelayed(msg(\u8fd9\u4e2a\u662f\u81ea\u52a8\u6784\u9020\u7684\u7a7a\u5185\u5bb9msg), delayMillis) ->…>sendMessageAtTime(Message msg, long uptimeMillis) \u8fd9\u4e2a\u662f\u6700\u7ec8\u51fd\u6570\uff0c uptimeMillis\u662f\u5f00\u673a\u5230\u76ee\u524d\u4e3a\u6b62\u7684\u662f\u95f4\u3002\u4e3a\u4ec0\u4e48\u4e0d\u7528SystemClock.currentMillis\u5462,\u56e0\u4e3a\u540e\u8005\u662f\u53d7\u5230\u7cfb\u7edf\u65f6\u95f4\u4fee\u6539\u5f71\u54cd\u7684\u3002
\n\u7ee7\u7eed\u770b\u4ee3\u7801<\/p>\n
[code lang=java]
\n public boolean sendMessageAtTime(Message msg, long uptimeMillis) {
\n MessageQueue queue = mQueue;
\n if (queue == null) {
\n RuntimeException e = new RuntimeException(
\n this + " sendMessageAtTime() called with no mQueue");
\n Log.w("Looper", e.getMessage(), e);
\n return false;
\n }
\n return enqueueMessage(queue, msg, uptimeMillis);
\n }
\n[\/code]<\/p>\n
\u6700\u7ec8\u4ee3\u7801\u8c03\u7528\u7684\u662fmessageQueue \u4e2d\u7684 eneueMessage \u65b9\u6cd5\uff0c\u6539\u65b9\u6cd5\u628a\u4f20\u5165\u7684Msg \u7684when \u8fdb\u884c\u94fe\u8868\u7ed3\u6784\u6392\u5e8f\uff08\u6bcf\u4e00\u4e2amsg\u90fd\u6709\u4e00\u4e2anext \u5f15\u7528) messageQueue \u5728Looper\u4e2d\u4e5f\u662f\u5b58\u5728\u7684<\/p>\n
\u6211\u4eec\u6765\u7b80\u5316\u4e00\u4e0b\u8fd9\u51e0\u4e2a\u7c7b \u5982\u4e0b\uff0c\u662f\u4e0d\u662f\u5f88\u660e\u4e86\u4e86\uff1f<\/p>\n
[code lang=java]
\npublic class Looper {
\n private static ThreadLocal<Looper> sThreadLocal = new ThreadLocal<>();<\/p>\n
MessageQueue mQueue;<\/p>\n
public static void prepare() {
\n sThreadLocal.set(new Looper());
\n }<\/p>\n
public static void loop() {
\n Looper l = myLooper();
\n for (; ; ) {
\n Message msg = l.mQueue.next();\/\/\u8fd9\u91cc\u53ef\u80fd\u963b\u585e \u770b\u4e0b\u9762\u7684MessageQueue
\n \/\/\u8fd9\u91cc\u6ee1\u8db3\u67d0\u79cd\u6761\u4ef6\u53ef\u4ee5\u9000\u51fa\u5faa\u73af
\n msg.target.dispatchMessage(msg);
\n }
\n }<\/p>\n
public static Looper myLooper() {
\n return sThreadLocal.get();
\n }<\/p>\n
private Looper() {
\n mQueue = new MessageQueue();
\n }
\n}<\/p>\n
public class Handler {
\n private Looper mLooper;
\n private MessageQueue mQueue;<\/p>\n
public Handler() {
\n mLooper = Looper.myLooper();
\n mQueue = mLooper.mQueue;
\n }<\/p>\n
public boolean sendMessage(Message msg) {
\n msg.target = this;
\n\/\/ SystemClock.uptimeMillis() \u8ba1\u7b97\u51fa\u4e00\u4e2a\u65f6\u95f4 \u653e\u5165\u4e0b\u9762\u7684msg\u4e2d\u53bb \u53c2\u6570\u662fwhen \u8fd9\u91cc\u5ffd\u7565
\n return mQueue.enqueueMessage(msg);
\n }<\/p>\n
protected void dispatchMessage(Message msg) {
\n }
\n}<\/p>\n
public class Message {
\n Message next;
\n Handler target;
\n}
\npublic class MessageQueue {
\n private Message messages;\/\/\u6301\u6709\u6700\u8fd1\u4e00\u4e2amessage<\/p>\n
boolean enqueueMessage(Message msg) {
\n \/\/\u8fd9\u91cc\u628amsg \u5217\u961f\u6392\u5e8f
\n if (messages == null) {
\n messages = msg;
\n } else {
\n \/\/\u8fd9\u91cc\u5176\u5b9e\u6709\u4e00\u4e2afor\u5faa\u73af\u53bb\u6bd4\u8f83when \u3002\u7136\u540e\u5c06msg \u653e\u5165\u6307\u5b9a\u4f4d\u7f6e,\u8fd9\u91cc\u5047\u5982msg \u5c31\u662f\u8981\u6700\u65b0\u6267\u884c\u7684\u7b80\u5355\u7248\u672c\u5904\u7406
\n msg.next = messages;
\n messages = msg;
\n }
\n return true;
\n }
\n Message next(){
\n \/\/\u8fd9\u91cc\u6709\u4e00\u4e2anative\u7684\u963b\u585e\u8fc7\u7a0b\uff0c
\n\/\/ nativePollOnce(ptr, nextPollTimeoutMillis);\u5c31\u662f \u8fd9\u4e2a\u65b9\u6cd5\uff0c
\n return messages;
\n }<\/p>\n
}<\/p>\n
[\/code]<\/p>\n
\u90a3\u6211\u4eec\u518d\u6765\u770b\u6700\u521d \u7684\u90a3\u4e2a\u4f8b\u5b50 \u5982\u679c\u5728\u5b50\u7ebf\u7a0b\u5b57\u8282 new Handler \u4f1a\u662f\u4ec0\u4e48\u4e2a\u60c5\u51b5\uff0c\u6211\u4eec\u53ef\u4ee5\u77e5\u9053myLooper\u8fd4\u56de\u7684\u503c\u4e00\u5b9a\u662f\u7a7a\u7684\uff0c\u6240\u4ee5\u4e0d\u884c\uff0c\u4ec0\u4e48\u60c5\u51b5\u4e0b\u4e0d\u4e3a\u7a7a\uff1f \u90a3\u5c31\u662f\u8c03\u7528\u4e86Looper.prepare\u4e4b\u540e\uff0c\u56e0\u6b64\uff0c\u5728new Handler \u7684\u65f6\u5019\u4e00\u5b9a\u4f1a\u9700\u8981prepare \u7684\uff0c\u90a3\u4e48\u5728\u4e3b\u7ebf\u7a0b\u4e2d \u662f\u4ec0\u4e48\u65f6\u5019\u5e2e\u6211\u4eec\u505a\u4e86\u8fd9\u4e2a\u4e8b\u60c5\u5462\uff0c\u90a3\u5c31\u662f\u5728activityThread.java \u7684main \u65b9\u6cd5\u91cc\u9762 \u53bb\u5e2e\u6211\u4eecprepare\u4e86MainLooper\u3002<\/p>\n
ThreadLocal \u662f\u6709\u4e00\u4e2a\u7279\u6027\uff0c\u90a3\u5c31\u662fset \u540e\u53ea\u6709\u5728\u540c\u4e00\u4e2a\u7ebf\u7a0b\u603b\u624d\u80fd\u8bbf\u95ee\u5230\uff0c\u4e5f\u5c31\u662f\u4f60\u65b0\u5f00\u7ebf\u7a0b\u4f60\u6ca1\u529e\u6cd5\u62ff\u5230\u4e3b\u7ebf\u7a0b\u5e2e\u6211\u4eecset\u7684looper\u3002\u56e0\u6b64\u6211\u4eec\u5728\u5b50\u7ebf\u7a0b\u4e2d\u5fc5\u987b\u518d\u6b21prepare\u4e00\u6b21<\/p>\n
————-\u5751\u7239\u7684\u5206\u5272\u7ebf\uff0c\u8fd1\u65e5tx \u7684\u9762\u8bd5\u5b98\u6700\u540e\u95ee\u4e86\u4e00\u4e2a\u95ee\u9898\uff0cThreadLocal\u539f\u7406\u662f\u4ec0\u4e48\uff1f\uff1f\uff1f WFC \u53c8\u4e00\u6b21\u6298\u621f\u6c89\u6c99———–
\n\u6765 \u7ee7\u7eed\u5206\u6790\u6e90\u7801\uff1a<\/p>\n
\u5728looper \u4e2d ThreadLocal \u662f\u4e00\u4e2a\u9759\u6001\u7684<\/p>\n
[code lang=text]
\n static final ThreadLocal<Looper> sThreadLocal = new ThreadLocal<Looper>();
\n[\/code]<\/p>\n
\u4fdd\u5b58\u4e86\u4e00\u4e2aLooper \u5b9e\u4f8b\uff0c\u90a3\u4e3a\u4ec0\u4e48 \u5728\u4e0d\u540c\u7684\u7ebf\u7a0b\u4e2d sThreadLocal.get()\u4e0d\u4e00\u6837\u5462\uff1f
\n\u6211\u5148\u770bset \u65b9\u6cd5\uff1a<\/p>\n
[code lang=java]
\n public void set(T value) {
\n Thread t = Thread.currentThread();
\n ThreadLocalMap map = getMap(t);
\n if (map != null)
\n map.set(this, value);
\n else
\n createMap(t, value);
\n }
\n[\/code]<\/p>\n
\u6bcf\u4e00\u4e2a\u7ebf\u7a0b\u90fd\u6709\u4e00\u4e2a ThreadLocalMap\u5bf9\u8c61\uff0c\u56e0\u6b64 \u5373\u4f7f\u662f\u540c\u4e00\u4e2a sThreadLocal \u5bf9\u8c61\uff0c\u5728set \u65b9\u6cd5\u4e2d\uff0c\u5176\u5b9e\u662f\u53d6\u5230\u4e86\u7ebf\u7a0b\u7684 ThradLocalMap\u5bf9\u8c61\uff0c\u6bcf\u4e00\u4e2a\u7ebf\u7a0b\u90fd\u662f\u4e0d\u4e00\u6837\u7684\u3002\u800c\u628a\u5f53\u524dThreadLocal \u5bf9\u8c61\u4f5c\u4e3aKey \u5b58\u5728\u4e86ThreadLocalMap\u4e2d\uff0c
\n\u5305\u542b\u5173\u7cfb\u5982\u4e0b\uff1a<\/p>\n
Thread -> ThreadLocalMap-> (ThreadLocal,Looper)<\/p>\n
ThreadLocalMap \u53c8\u662f\u4e00\u4e2a\u4ec0\u4e48\u4e1c\u897f\u5462\uff1f
\n\u67e5\u770b\u4ee3\u7801\u5176\u5e76\u6ca1\u6709\u7ee7\u627f\u81eaMap\u63a5\u53e3\u3002 \u91cc\u9762\u6709\u4e00\u4e2atable \u6570\u7ec4\u4e3a\u6210\u5458\u53d8\u91cf<\/p>\n
[code lang=java]
\n private Entry[] table;<\/p>\n
static class Entry extends WeakReference<ThreadLocal<?>> {
\n \/** The value associated with this ThreadLocal. *\/
\n Object value;<\/p>\n
Entry(ThreadLocal<?> k, Object v) {
\n super(k);
\n value = v;
\n }
\n }
\n[\/code]<\/p>\n
Entry \u662f \u7ee7\u627f\u81ea\u5f31\u5f15\u7528\u7684\u3002\u56e0\u6b64\u8fd9\u4e2aKey \u53ef\u4ee5\u968f\u65f6\u88ab\u9500\u6bc1\uff0c
\n\u4e0a\u9762\u4ee3\u7801\u610f\u5473\u7740\u4e0d\u50cfhashmap \u90a3\u6837\u662f\u4e00\u4e2a\u6570\u7ec4\u518d\u52a0\u4e0a\u4e00\u4e2a\u94fe\u8868\u53bb\u67e5\u8be2\uff0c\u90a3\u5982\u4f55\u89e3\u51b3hash\u51b2\u7a81\u5462\uff1f
\n\u770bSet \u65b9\u6cd5<\/p>\n
[code lang=java]
\nprivate void set(ThreadLocal<?> key, Object value) {<\/p>\n
\/\/ We don't use a fast path as with get() because it is at
\n \/\/ least as common to use set() to create new entries as
\n \/\/ it is to replace existing ones, in which case, a fast
\n \/\/ path would fail more often than not.<\/p>\n
Entry[] tab = table;
\n int len = tab.length;
\n int i = key.threadLocalHashCode & (len-1);<\/p>\n
for (Entry e = tab[i];
\n e != null;
\n e = tab[i = nextIndex(i, len)]) {
\n ThreadLocal<?> k = e.get();<\/p>\n
if (k == key) {
\n e.value = value;
\n return;
\n }<\/p>\n
if (k == null) {
\n replaceStaleEntry(key, value, i);
\n return;
\n }
\n }<\/p>\n
tab[i] = new Entry(key, value);
\n int sz = ++size;
\n if (!cleanSomeSlots(i, sz) && sz >= threshold)
\n rehash();
\n }<\/p>\n
[\/code]<\/p>\n
\u53ef\u4ee5\u770b\u5230\uff0c\u5982\u679c\u627e\u5230\u51b2\u7a81\u7684hash \u800c\u4e14key \u4e0d\u76f8\u7b49\uff0c\u5c31\u4f1a\u5f80\u6570\u7ec4\u540e\u79fb\uff0c\u627e\u5230\u4e00\u4e2aEntry\u7a7akey\u5e76\u66ff\u6362\u3002 \u5982\u679c\u627e\u5230Entry\u4e3a\u7a7a\uff0c\u5219\u65b0\u589e\u4e00\u4e2aEntry\u5230\u5f53\u524d\u6570\u7ec4\u4f4d\u7f6e\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
\u5411\u6765\u89c9\u5f97\u7535\u8bdd\u9762\u8bd5\u5c31\u89c9\u5f97\u80af\u5b9a\u9ec4\uff0c\u603b\u6709\u4e00\u79cd\u5c40\u4fc3\u548c\u4e0d\u5b89\uff0c\u4eca\u5929\u63a5\u5230\u963f\u91cc\u7684\u7535\u8bdd\u9762\uff0c\u5f53\u65f6\u5728\u5bb6\u91cc\u3002\u95ee\u7684\u95ee\u9898\u8fd8\u662f\u90a3\u51e0\u4e2a\u8001\u751f\u5e38\u8c08\u7684\u95ee\u9898\u3002 view \u7684\u7ed8\u5236\u554a\uff0c handler \u673a\u5236\u554a\uff0chashmap\u5b9e\u73b0\u539f\u7406\u554a\u3002\u6548\u7387\u554a\uff0c\u4f18\u5316\u554a\u5565\u7684\u3002 \u4eca\u5929\u53ef\u8c13\u662f\u90fd\u78b0\u4e0a\u4e86\uff08\u5176\u5b9e\u8fd8\u5dee\u90a3\u4e2aasyntask \u554a http\u534f\u8bae\u554a \u591a\u7ebf\u7a0b\u540c\u6b65\u554a\uff0cjvm \u554a\uff0c\u542f\u52a8\u6d41\u7a0b\u554a\u5df4\u62c9\u5df4\u62c9\uff09\uff0c\u8fd9\u4e00\u5173\u4e0d\u8fc7\uff0c\u4e0b\u4e00\u5173\u5c31\u6ca1\u95e8\u554a\uff0c\u5176\u5b9e\u8fd9\u4e2a\u548c\u9879\u76ee\u7ecf\u9a8c\u6216\u8005\u4e00\u4e2a\u4eba\u80fd\u4e0d\u80fd\u505a\u6210\u4e8b\u60c5\u5e76\u6ca1\u6709\u592a\u5927\u5173\u7cfb\uff0c\u6700\u9ad8\u7684\u667a\u5546\u662f\u628a\u4e8b\u505a\u6210\uff0c\u6700\u9ad8\u7684\u60c5\u5546\u662f\u9760\u8c31\u3002 \u4ee5\u524d\u5de5\u4f5c\u6ca1\u90a3\u4e48\u591a\u95f2\u60c5\u770b\u8fd9\u4e2a\uff0c\u90a3\u4eca\u5929\u5c31\u5e26\u7740\u9762\u8bd5\u7684\u76ee\u7684\u6765\u5f7b\u5e95\u7814\u7a76\u4e00\u4e0b \u9762\u8bd5\u7b2c\u4e00\u9898 Handler\u673a\u5236\u3002 \u4ece\u5e94\u7528\u5f00\u53d1\u8fd9\u4e2a\u89d2\u5ea6\u6765\u770b\uff0c\u5927\u5bb6\u53ef\u80fd\u90fd\u77e5\u9053 \u4e0d\u80fd\u5728\u5b50\u7ebf\u7a0b\u4e2d\u76f4\u63a5new \u4e00\u4e2ahander\u3002\u5426\u5219\u4f1a\u629b\u51fa\u5e38\u89c1\u7684 [code lang=text] java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare() [\/code] \u7136\u540e\u5927\u5bb6\u4e5f\u77e5\u9053(\u4e0a\u9762\u660e\u663e\u63d0\u793a)\uff0c\u5728\u5b50\u7ebf\u7a0b\u4e2d\u5047\u5982\u8981\u521b\u5efahandler \u53ef\u4ee5\u5148Looper.prepare()\u7136\u540e\u5c31\u53ef\u4ee5\u521b\u5efa\u4e86\u3002 \u6211\u4eec\u5199\u4e00\u4e2a\u5e38\u89c1\u7684\u7528handler \u8fdb\u884c\u7ebf\u7a0b\u95f4\u901a\u8baf\u4f8b\u5b50\uff0c\u5b50\u7ebf\u7a0b\u53d1\u9001\u6d88\u606f\u7ed9\u4e3b\u7ebf\u7a0b\u66f4\u65b0UI<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,8],"tags":[],"_links":{"self":[{"href":"https:\/\/blog.xiunian.wang\/index.php?rest_route=\/wp\/v2\/posts\/1126"}],"collection":[{"href":"https:\/\/blog.xiunian.wang\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.xiunian.wang\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.xiunian.wang\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.xiunian.wang\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1126"}],"version-history":[{"count":8,"href":"https:\/\/blog.xiunian.wang\/index.php?rest_route=\/wp\/v2\/posts\/1126\/revisions"}],"predecessor-version":[{"id":1286,"href":"https:\/\/blog.xiunian.wang\/index.php?rest_route=\/wp\/v2\/posts\/1126\/revisions\/1286"}],"wp:attachment":[{"href":"https:\/\/blog.xiunian.wang\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1126"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.xiunian.wang\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1126"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.xiunian.wang\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1126"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}