function setStyle (domStyle, style, value) {
  if (isNullOrUndef(value) || (isNumber(value) && isNaN(value))) {
    domStyle[style] = ''
    return
  }
  if (style === 'float') {
    domStyle['cssFloat'] = value
    domStyle['styleFloat'] = value
    return
  }
  domStyle[style] =
    !isNumber(value) || IS_NON_DIMENSIONAL.test(style) ? value : value + 'px'
}

function h (type: string, props: Props, children?: VirtualChildren) {
  let childNodes
  if (props.children) {
    if (!children) {
      children = props.children
    }
    delete props.children
  }
  if (isArray(children)) {
    childNodes = []
    addChildren(childNodes, children as any, type)
  } else if (isString(children) || isNumber(children)) {
    children = createVText(String(children))
  } else if (!isValidElement(children)) {
    children = EMPTY_CHILDREN
  }
  return createVNode(
    type,
    props,
    childNodes !== undefined ? childNodes : children,
    props.key,
    props.namespace,
    props.owner,
    props.ref
  ) as VNode
}

export function renderComponent (component: Component<any, any>) {
  CurrentOwner.current = component
  let rendered
  errorCatcher(() => {
    rendered = component.render()
  }, component)
  if (isNumber(rendered) || isString(rendered)) {
    rendered = createVText(rendered)
  } else if (isUndefined(rendered)) {
    rendered = createVoid()
  }
  CurrentOwner.current = null
  return rendered
}

function addChildren (
  childNodes: VirtualNode[],
  children: VirtualNode | VirtualNode[],
  type: string
) {
  if (isString(children) || isNumber(children)) {
    childNodes.push(createVText(String(children)))
  } else if (isValidElement(children)) {
    childNodes.push(children)
  } else if (isArray(children)) {
    for (let i = 0; i < children.length; i++) {
      addChildren(childNodes, children[i], type)
    }
  }
}

function renderStylesToString (styles: string | object): string {
  if (isString(styles)) {
    return styles
  } else {
    let renderedString = ''
    for (const styleName in styles) {
      const value = styles[styleName]

      if (isString(value)) {
        renderedString += `${getCssPropertyName(styleName)}${value};`
      } else if (isNumber(value)) {
        renderedString += `${getCssPropertyName(
          styleName
        )}${value}${isUnitlessNumber[styleName] ? '' : 'px'};`
      }
    }
    return renderedString
  }
}

function createElement (
  vnode: VirtualNode | VirtualNode[],
  isSvg?: boolean,
  parentContext?,
  parentComponent?
): Element | Text | Comment | DocumentFragment | null {
  let domNode
  if (isValidElement(vnode)) {
    const vtype = vnode.vtype
    if (vtype & (VType.Composite | VType.Stateless)) {
      domNode = (vnode as CompositeComponent).init(parentContext, parentComponent)
      options.afterMount(vnode as CompositeComponent)
    } else if (vtype & VType.Text) {
      domNode = doc.createTextNode((vnode as any).text);
      (vnode as any).dom = domNode
    } else if (vtype & VType.Node) {
      domNode = mountVNode(vnode as any, isSvg, parentContext, parentComponent)
    } else if (vtype & VType.Void) {
      domNode = (vnode as any).dom
    }
  } else if (isString(vnode) || isNumber(vnode)) {
    domNode = doc.createTextNode(vnode as string)
  } else if (isNullOrUndef(vnode) || (vnode as any) === false) {
    domNode = doc.createTextNode('')
  } else if (isArray(vnode)) {
    domNode = doc.createDocumentFragment()
    vnode.forEach((child) => {
      if (!isInvalid(child)) {
        const childNode = createElement(child, isSvg, parentContext, parentComponent)
        if (childNode) {
          domNode.appendChild(childNode)
        }
      }
    })
  } else {
    throw new Error('Unsupported VNode.')
  }
  return domNode
}

function isVChild (vnode): vnode is string | number | VNode {
  return isVNode(vnode) || isString(vnode) || isNumber(vnode)
}

function renderVNodeToString (vnode, parent, context, isSvg?: boolean) {
  if (isInvalid(vnode)) {
    return ''
  }
  const { type, props, children } = vnode
  if (isVText(vnode)) {
    return encodeEntities(vnode.text)
  } else if (isVNode(vnode)) {
    let renderedString = `<${type}`
    let html
    if (!isNullOrUndef(props)) {
      for (let prop in props) {
        const value = props[prop]
        if (skipAttributes[prop]) {
          continue
        }
        if (prop === 'dangerouslySetInnerHTML') {
          html = value.__html
        } else if (prop === 'style') {
          const styleStr = renderStylesToString(value)
          renderedString += styleStr ? ` style="${renderStylesToString(value)}"` : ''
        } else if (prop === 'class' || prop === 'className') {
          renderedString += ` class="${isString(value)
            ? value
            : hashToClassName(value)}"`
        } else if (prop === 'defaultValue') {
          if (!props.value) {
            renderedString += ` value="${encodeEntities(value)}"`
          }
        } else if (prop === 'defaultChecked') {
          if (!props.checked) {
            renderedString += ` checked="${value}"`
          }
        } else if (isSvg && prop.match(/^xlink\:?(.+)/)) {
          prop = prop.toLowerCase().replace(/^xlink\:?(.+)/, 'xlink:$1')
          renderedString += ` ${prop}="${encodeEntities(value)}"`
        } else {
          if (isString(value)) {
            renderedString += ` ${prop}="${encodeEntities(value)}"`
          } else if (isNumber(value)) {
            renderedString += ` ${prop}="${value}"`
          } else if (value === true) {
            renderedString += ` ${prop}`
          }
        }
      }
    }
    if (isVoidElements[type]) {
      renderedString += `/>`
    } else {
      renderedString += `>`
      if (html) {
        renderedString += html
      } else if (!isInvalid(children)) {
        if (isString(children)) {
          renderedString += children === '' ? ' ' : encodeEntities(children)
        } else if (isNumber(children)) {
          renderedString += children + ''
        } else if (isArray(children)) {
          for (let i = 0, len = children.length; i < len; i++) {
            const child = children[i]
            if (isString(child)) {
              renderedString += child === '' ? ' ' : encodeEntities(child)
            } else if (isNumber(child)) {
              renderedString += child
            } else if (!isInvalid(child)) {
              isSvg = type === 'svg' ? true : type === 'foreignObject' ? false : isSvg
              renderedString += renderVNodeToString(
                child,
                vnode,
                context,
                isSvg
              )
            }
          }
        } else {
          isSvg = type === 'svg' ? true : type === 'foreignObject' ? false : isSvg
          renderedString += renderVNodeToString(children, vnode, context, isSvg)
        }
      }
      if (!isVoidElements[type]) {
        renderedString += `</${type}>`
      }
    }
    return renderedString
  } else if (isComposite(vnode)) {
    const instance = new type(props, context)
    instance._disable = true
    instance.props = props
    instance.context = context
    if (isFunction(instance.componentWillMount)) {
      instance.componentWillMount()
    }
    const rendered = instance.render()
    if (isFunction(instance.getChildContext)) {
      context = extend(clone(context), instance.getChildContext())
    }
    return renderVNodeToString(rendered, vnode, context, isSvg)
  } else if (isStateless(vnode)) {
    const rendered = type(props, context)
//.........这里部分代码省略.........