frame_manager.py 文件源码

def querySelector(self, selector: str) -> Optional['ElementHandle']:
        """Get element which matches `selector` string.

        If `selector` matches multiple elements, return first-matched element.
        """
        remoteObject = await self._rawEvaluate(
            'selector => document.querySelector(selector)', selector)
        if remoteObject.get('subtype') == 'node':
            return ElementHandle(self._client, remoteObject, self._mouse,
                                 self._touchscreen)
        await helper.releaseObject(self._client, remoteObject)
        return None