ActionChains 类不仅仅是只包含了上面的三个方法，下面将方法列出：

　　class ActionChains(driver)

driver:The WebDriver instance which performs user actions.
Generate user actions. All actions are stored in the ActionChains object. Call perform() to fire stored actions.
– perform()
Performs all stored actions.
– click(on_element=None)
Clicks an element.
on_element:The element to click. If None， clicks on current mouse position.
– click_and_hold(on_element)
Holds down the left mouse button on an element.
on_element:The element to mouse down. If None， clicks on current mouse position.
– context_click(on_element)
Performs a context-click (right click) on an element.
on_element:The element to context-click. If None， clicks on current mouse position.
– double_click(on_element)
Double-clicks an element.
on_element:The element to double-click. If None， clicks on current mouse position.
– drag_and_drop(source， target)
Holds down the left mouse button on the source element， then moves to the target element and releases the mouse button.
source:The element to mouse down.
target: The element to mouse up.
– key_down(key， element=None)
Sends a key press only， without releasing it. Should only be used with modifier keys (Control， Alt andShift).
key:The modifier key to send. Values are defined in Keys class.
element:The element to send keys. If None， sends a key to current focused element.
– key_up(key， element=None)
Releases a modifier key.
key:The modifier key to send. Values are defined in Keys class.
element:The element to send keys. If None， sends a key to current focused element.
– move_by_offset(xoffset， yoffset)
Moving the mouse to an offset from current mouse position.
xoffset:X offset to move to.yoffset:Y offset to move to.
– move_to_element(to_element)
Moving the mouse to the middle of an element.
to_element: The element to move to.
– move_to_element_with_offset(to_element， xoffset， yoffset)
Move the mouse by an offset of the specificed element. Offsets are relative to the top-left corner of the
element.
to_element: The element to move to.xoffset:X offset to move to.yoffset:Y offset to move to.
– release(on_element)
Releasing a held mouse button.
on_element:The element to mouse up.
– send_keys(*keys_to_send)
Sends keys to current focused element.
keys_to_send:The keys to send.
– send_keys_to_element(self， element，*keys_to_send):
Sends keys to an element.
element:The element to send keys.keys_to_send:The keys to send.