Hvac一次卡顿问题分析
通过查看anr/下的dumptrace日志，搜索空调包名，发现如下日志
"main" prio=5 tid=1 Native | group="main" sCount=1 dsCount=0 flags=1 obj=0x731f9d08 self=0xb4000074f82f5380 | sysTid=2790 nice=0 cgrp=foreground sched=0/0 handle=0x767ee3b4f8 | state=R schedstat=( 43403965835908 128373803042 1427593 ) utm=4024919 stm=315476 core=1 HZ=100 | stack=0x7fe0477000-0x7fe0479000 stackSize=8192KB | held mutexes= native: #00 pc 00000000000126ec /system/lib64/libz.so (inflate_fast+412) native: #01 pc 0000000000010d00 /system/lib64/libz.so (inflate+4628) native: #02 pc 0000000000017b90 /system/lib64/libpng.so (png_process_IDAT_data+132) native: #03 pc 0000000000017968 /system/lib64/libpng.so (png_push_read_IDAT+480) native: #04 pc 0000000000016c60 /system/lib64/libpng.so (png_process_data+124) native: #05 pc 0000000000252fc8 /system/lib64/libhwui.so (SkPngCodec::processData()+344) native: #06 pc 0000000000254118 /system/lib64/libhwui.so (SkPngNormalDecoder::decodeAllRows(void*, unsigned long, int*)+96) native: #07 pc 000000000024acd4 /system/lib64/libhwui.so (SkCodec::getPixels(SkImageInfo const&, void*, unsigned long, SkCodec::Options const*)+336) native: #08 pc 0000000000254e04 /system/lib64/libhwui.so (SkSampledCodec::onGetAndroidPixels(SkImageInfo const&, void*, unsigned long, SkAndroidCodec::AndroidOptions const&)+540) native: #09 pc 0000000000246174 /system/lib64/libhwui.so (SkAndroidCodec::getAndroidPixels(SkImageInfo const&, void*, unsigned long, SkAndroidCodec::AndroidOptions const*)+744) native: #10 pc 00000000001b8508 /system/lib64/libhwui.so (doDecode(_JNIEnv*, std::__1::unique_ptr<SkStreamRewindable, std::__1::default_delete<SkStreamRewindable> >, _jobject*, _jobject*, long, long)+2856) native: #11 pc 00000000001b7828 /system/lib64/libhwui.so (nativeDecodeAsset(_JNIEnv*, _jobject*, long, _jobject*, _jobject*, long, long)+112) at android.graphics.BitmapFactory.nativeDecodeAsset(Native method) at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:762) at android.graphics.BitmapFactory.decodeResourceStream(BitmapFactory.java:575) at android.graphics.BitmapFactory.decodeResource(BitmapFactory.java:604) at com.desaysv.svhvac.view.widget.FrameAnimationView.a(SourceFile:174) at com.desaysv.svhvac.view.widget.FrameAnimationView.d(SourceFile:142) at com.desaysv.svhvac.view.widget.FrameAnimationView.a(SourceFile:27) at com.desaysv.svhvac.view.widget.FrameAnimationView$1.handleMessage(SourceFile:109) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:223) at android.app.ActivityThread.main(ActivityThread.java:7705) at java.lang.reflect.Method.invoke(Native method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1001)这是主线程（main 线程）在做【同步 PNG 图片解码】，把 UI 线程堵死了 → 直接造成卡顿、掉帧、操作延迟！
为什么会卡？
图片解码是耗时、耗 CPU操作
绝对不能在主线程做！
但hvac代码的 FrameAnimationView 偏偏就在主线程解码帧动画 → 不卡才怪。
既然指出具体类，那么直接对此处理就好了
if (getVisibility() == VISIBLE) { // 异步解码 Bitmap，避免阻塞主线程 final int currentIndex = mIndex; mLoadTask = mExecutor.submit(() -> { Bitmap newBitmap = decodeBitmap(mDrawables[currentIndex]); if (newBitmap != null) { post(() -> { // 在 UI 线程更新 Bitmap if (mCurrentBitmap != null && !mCurrentBitmap.isRecycled()) { mCurrentBitmap.recycle(); } mCurrentBitmap = newBitmap; invalidate(); }); } }); }非预加载模式下，将 decodeBitmap() 移到后台线程执行（使用已有的 mExecutor 线程池）
解码完成后通过 post() 回到 UI 线程更新 mCurrentBitmap 并调用 invalidate()
复用现有的 mLoadTask 来管理任务，可以在切换资源时取消未完成的加载
预加载模式不受影响，因为它已经是在后台线程加载的
这样修改后，主线程只负责调度和绘制，耗时的 Bitmap 解码在后台线程完成，不会再造成卡顿