本文共 1683 字，大约阅读时间需要 5 分钟。

看下executeLifecycleState 方法

/** Transition to the final state if requested by the transaction. */    private void executeLifecycleState(ClientTransaction transaction) {        final ActivityLifecycleItem lifecycleItem = transaction.getLifecycleStateRequest();        if (lifecycleItem == null) {            // No lifecycle request, return early.            return;        }        log("Resolving lifecycle state: " + lifecycleItem);        final IBinder token = transaction.getActivityToken();        final ActivityClientRecord r = mTransactionHandler.getActivityClient(token);        if (r == null) {            // Ignore requests for non-existent client records for now.            return;        }        // Cycle to the state right before the final requested state.        cycleToPath(r, lifecycleItem.getTargetState(), true /* excludeLastState */);        // Execute the final transition with proper parameters.        lifecycleItem.execute(mTransactionHandler, token, mPendingActions);        lifecycleItem.postExecute(mTransactionHandler, token, mPendingActions);    }

先是cycleToPath,这个方法会执行 

mTransactionHandler.handleStartActivity(r, mPendingActions);

（onResume和oncreate之间只有这一个方法）

然后就是ResumeActivityItem里面的execute

@Override    public void execute(ClientTransactionHandler client, IBinder token,            PendingTransactionActions pendingActions) {        Trace.traceBegin(TRACE_TAG_ACTIVITY_MANAGER, "activityResume");        client.handleResumeActivity(token, true /* finalStateRequest */, mIsForward,                "RESUME_ACTIVITY");        Trace.traceEnd(TRACE_TAG_ACTIVITY_MANAGER);    }

调用了handleResumeActivity 这个方法。

通过层层调用最后调用Activity.onResume...

终于。。。Activity启动完毕。。。

转载地址：https://blog.csdn.net/perfectnihil/article/details/91048578 如侵犯您的版权，请留言回复原文章的地址，我们会给您删除此文章，给您带来不便请您谅解！