近日公司需求跟得不緊，就自己找事優化，重構，找記憶體洩漏(如有錯誤，煩請拍磚)

記憶體洩漏工具之前的寫的部落格也有介紹 記憶體洩漏檢測工具很好用，下面用LeakCanary找一個微信登入引起的記憶體洩漏(其實微信是有做釋放操作，但是文件和demo中沒有見到)

洩漏資訊

圖中可以看出自己應用的WeChatLoginActivity的例項沒有回收掉導致的記憶體洩漏，再往上是WXApiImpV10中的一個內部類ActivityLifecycleCb中持有WeChatLoginActivity的例項導致的

不多說看微信SDK原始碼

檢視createWXAPI的方法(因為WeChatLoginActivity

    public static IWXAPI createWXAPI(Context var0, String var1, boolean var2) {
        b.e("MicroMsg.PaySdk.WXFactory", "createWXAPI, appId = " + var1 + ", checkSignature = " + var2);
        return new WXApiImplV10(var0, var1, var2);
    }

構造方法儲存了context，registerApp方法中建立了activitycb，而且我們的洩漏最終是activitycb

   private static final class ActivityLifecycleCb implements ActivityLifecycleCallbacks {
        private static final String TAG = "MicroMsg.SDK.WXApiImplV10.ActivityLifecycleCb";
        private static final int DELAYED = 800;
        private boolean isForeground;
        private Handler handler;
        private Context context;
        private Runnable onPausedRunnable;
        private Runnable onResumedRunnable;

        private ActivityLifecycleCb(Context var1) {
            this.isForeground = false;
            this.handler = new Handler(Looper.getMainLooper());
            this.onPausedRunnable = new Runnable() {
                public void run() {
                    if(WXApiImplV10.activityCb != null && ActivityLifecycleCb.this.isForeground) {
                        Log.v("MicroMsg.SDK.WXApiImplV10.ActivityLifecycleCb", "WXStat trigger onBackground");
                        StatService.trackCustomKVEvent(ActivityLifecycleCb.this.context, "onBackground_WX", (Properties)null);
                        ActivityLifecycleCb.this.isForeground = false;
                    }

                }
            };
            this.onResumedRunnable = new Runnable() {
                public void run() {
                    if(WXApiImplV10.activityCb != null && !ActivityLifecycleCb.this.isForeground) {
                        Log.v("MicroMsg.SDK.WXApiImplV10.ActivityLifecycleCb", "WXStat trigger onForeground");
                        StatService.trackCustomKVEvent(ActivityLifecycleCb.this.context, "onForeground_WX", (Properties)null);
                        ActivityLifecycleCb.this.isForeground = true;
                    }

                }
            };
            this.context = var1;
        }

        public final void onActivityCreated(Activity var1, Bundle var2) {
        }

        public final void onActivityDestroyed(Activity var1) {
        }

        public final void onActivityPaused(Activity var1) {
            Log.v("MicroMsg.SDK.WXApiImplV10.ActivityLifecycleCb", var1.getComponentName().getClassName() + "  onActivityPaused");
            this.handler.removeCallbacks(this.onResumedRunnable);
            this.handler.postDelayed(this.onPausedRunnable, 800L);
        }

        public final void onActivityResumed(Activity var1) {
            Log.v("MicroMsg.SDK.WXApiImplV10.ActivityLifecycleCb", var1.getComponentName().getClassName() + "  onActivityResumed");
            this.handler.removeCallbacks(this.onPausedRunnable);
            this.handler.postDelayed(this.onResumedRunnable, 800L);
        }

        public final void onActivitySaveInstanceState(Activity var1, Bundle var2) {
        }

        public final void onActivityStarted(Activity var1) {
        }

        public final void onActivityStopped(Activity var1) {
        }

        public final void detach() {
            this.handler.removeCallbacks(this.onResumedRunnable);
            this.handler.removeCallbacks(this.onPausedRunnable);
            this.context = null;
        }
    }
 

在WeChatLoginActivity中的onDestroy中呼叫IWXAPI.detach();即可

因為微信登入正常就開啟第一次然後就不會再開啟，所以這個記憶體洩漏基本不會遇到。