Question

我怀疑光纤有错误

我在0.59的React-Native中使用了一些Hook。我的反应版本是16.8.3。

  flushedNode.next = flushedNode.previous = null;
  // Now it's safe to call the callback.
  var callback = flushedNode.callback;
  var expirationTime = flushedNode.expirationTime;
  var priorityLevel = flushedNode.priorityLevel;
  var previousPriorityLevel = currentPriorityLevel;
  var previousExpirationTime = currentExpirationTime;
  currentPriorityLevel = priorityLevel;
  currentExpirationTime = expirationTime;
  var continuationCallback;
  try {
    [ this is the mistake ]  continuationCallback = callback();
  } finally {
    currentPriorityLevel = previousPriorityLevel;
    currentExpirationTime = previousExpirationTime;
  }

现在，让我展示这个错误。

flushedNode is {
    callback: 3,
    expirationTime: 220678.60500000097,
    next: null,
    previous: null,
    priorityLevel: 3,
    __proto__: Object
}

回调应该是一个函数，但是它显示为3，所以应用程序崩溃了，为什么？

Answer 1

在最新的不稳定版本中，https://github.com/facebook/react/blob/master/packages/scheduler/src/Scheduler.js#L320

function unstable_scheduleCallback(priorityLevel, callback, options) {
   var newTask = {
    id: taskIdCounter++,
    callback,
    ...
   }
   return newTask
}

是的，它应该是您用来计划的回调。并且此回调稍后用于执行workLoop，https://github.com/facebook/react/blob/master/packages/scheduler/src/Scheduler.js#L185

中的工作

为什么在React Scheduler中回调不起作用？

1 个答案: