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文章目录
  1. 1. 源码的结论
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function enqueueUpdate(component) {
ensureInjected();
    // Various parts of our code (such as ReactCompositeComponent's
    // _renderValidatedComponent) assume that calls to render aren't nested;
    // verify that that's the case. (This is called by each top-level update
    // function, like setProps, setState, forceUpdate, etc.; creation and
    // destruction of top-level components is guarded in ReactMount.)
    if (!batchingStrategy.isBatchingUpdates) {
        batchingStrategy.batchedUpdates(enqueueUpdate, component);
        return;
    }
    dirtyComponents.push(component);
    }

源码的结论

  • react在执行top-level事件的时候，在整个冒泡及生命周期中会有个更新策略，等到所有的脏元素准备就绪的时候(在settimeout之前，在冒泡结束节点)，统一执行setState。
  • react在执行非top-level事件的时候，会执行batchUpdate，进行局部的state的更新。完成dom树的patch
文章目录
  1. 1. 源码的结论