Selenium提供了一个类ActionChains来处理模拟鼠标事件，如单击、双击、拖动等。
　　基本语法：
class ActionChains(object):
"""
ActionChains are a way to automate low level interactions such as
mouse movements， mouse button actions， key press， and context menu interactions.
This is useful for doing more complex actions like hover over and drag and drop.
Generate user actions.
When you call methods for actions on the ActionChains object，
the actions are stored in a queue in the ActionChains object.
When you call perform()， the events are fired in the order they
are queued up.
ActionChains can be used in a chain pattern::
menu = driver.find_element_by_css_selector(".nav")
hidden_submenu = driver.find_element_by_css_selector(".nav #submenu1")
ActionChains(driver).move_to_element(menu).click(hidden_submenu).perform()
Or actions can be queued up one by one， then performed.::
menu = driver.find_element_by_css_selector(".nav")
hidden_submenu = driver.find_element_by_css_selector(".nav #submenu1")
actions = ActionChains(driver)
actions.move_to_element(menu)
actions.click(hidden_submenu)
actions.perform()
Either way， the actions are performed in the order they are called， one after
another.
"""
def __init__(self， driver):
"""
Creates a new ActionChains.
:Args:
- driver: The WebDriver instance which performs user actions.
"""
self._driver = driver
self._actions = []
if self._driver.w3c:
self.w3c_actions = ActionBuilder(driver)
def perform(self):
"""
Performs all stored actions.
"""
if self._driver.w3c:
self.w3c_actions.perform()
else:
for action in self._actions:
action()
def reset_actions(self):
"""
Clears actions that are already stored on the remote end.
"""
if self._driver.w3c:
self._driver.execute(Command.W3C_CLEAR_ACTIONS)
else:
self._actions = []
def click(self， on_element=None):
"""
Clicks an element.
:Args:
- on_element: The element to click.
If None， clicks on current mouse position.
"""
if self._driver.w3c:
self.w3c_actions.pointer_action.click(on_element)
self.w3c_actions.key_action.pause()
self.w3c_actions.key_action.pause()
else:
if on_element:
self.move_to_element(on_element)
self._actions.append(lambda: self._driver.execute(
Command.CLICK， {'button': 0}))
return self
def click_and_hold(self， on_element=None):
"""
Holds down the left mouse button on an element.
:Args:
- on_element: The element to mouse down.
If None， clicks on current mouse position.
"""
if self._driver.w3c:
self.w3c_actions.pointer_action.click_and_hold(on_element)
self.w3c_actions.key_action.pause()
if on_element:
self.w3c_actions.key_action.pause()
else:
if on_element:
self.move_to_element(on_element)
self._actions.append(lambda: self._driver.execute(
Command.MOUSE_DOWN， {}))
return self
def context_click(self， on_element=None):
"""
Performs a context-click (right click) on an element.
:Args:
- on_element: The element to context-click.
If None， clicks on current mouse position.
"""
if self._driver.w3c:
self.w3c_actions.pointer_action.context_click(on_element)
self.w3c_actions.key_action.pause()
else:
if on_element:
self.move_to_element(on_element)
self._actions.append(lambda: self._driver.execute(
Command.CLICK， {'button': 2}))
return self
def double_click(self， on_element=None):
"""
Double-clicks an element.
:Args:
- on_element: The element to double-click.
If None， clicks on current mouse position.
"""
if self._driver.w3c:
self.w3c_actions.pointer_action.double_click(on_element)
for _ in range(4):
self.w3c_actions.key_action.pause()
else:
if on_element:
self.move_to_element(on_element)
self._actions.append(lambda: self._driver.execute(
Command.DOUBLE_CLICK， {}))
return self
def drag_and_drop(self， source， target):
"""
Holds down the left mouse button on the source element，
then moves to the target element and releases the mouse button.
:Args:
- source: The element to mouse down.
- target: The element to mouse up.
"""
if self._driver.w3c:
self.w3c_actions.pointer_action.click_and_hold(source)
.move_to(target)
.release()
for _ in range(3):
self.w3c_actions.key_action.pause()
else:
self.click_and_hold(source)
self.release(target)
return self
def drag_and_drop_by_offset(self， source， xoffset， yoffset):
"""
Holds down the left mouse button on the source element，
then moves to the target offset and releases the mouse button.
:Args:
- source: The element to mouse down.
- xoffset: X offset to move to.
- yoffset: Y offset to move to.
"""
if self._driver.w3c:
self.w3c_actions.pointer_action.click_and_hold(source)
.move_to_location(xoffset， yoffset)
.release()
for _ in range(3):
self.w3c_actions.key_action.pause()
else:
self.click_and_hold(source)
self.move_by_offset(xoffset， yoffset)
self.release()
return self
def key_down(self， value， element=None):
"""
Sends a key press only， without releasing it.
Should only be used with modifier keys (Control， Alt and Shift).
:Args:
- value: 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.
Example， pressing ctrl+c::
ActionChains(driver).key_down(Keys.CONTROL).send_keys('c').key_up(Keys.CONTROL).perform()
"""
if element:
self.click(element)
if self._driver.w3c:
self.w3c_actions.key_action.key_down(value)
self.w3c_actions.pointer_action.pause()
else:
self._actions.append(lambda: self._driver.execute(
Command.SEND_KEYS_TO_ACTIVE_ELEMENT，
{"value": keys_to_typing(value)}))
return self
def key_up(self， value， element=None):
"""
Releases a modifier key.
:Args:
- value: 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.
Example， pressing ctrl+c::
ActionChains(driver).key_down(Keys.CONTROL).send_keys('c').key_up(Keys.CONTROL).perform()
"""
if element:
self.click(element)
if self._driver.w3c:
self.w3c_actions.key_action.key_up(value)
self.w3c_actions.pointer_action.pause()
else:
self._actions.append(lambda: self._driver.execute(
Command.SEND_KEYS_TO_ACTIVE_ELEMENT，
{"value": keys_to_typing(value)}))
return self
def move_by_offset(self， xoffset， yoffset):
"""
Moving the mouse to an offset from current mouse position.
:Args:
- xoffset: X offset to move to， as a positive or negative integer.
- yoffset: Y offset to move to， as a positive or negative integer.
"""
self._actions.append(lambda: self._driver.execute(
Command.MOVE_TO， {
'xoffset': int(xoffset)，
'yoffset': int(yoffset)}))
return self
def move_to_element(self， to_element):
"""
Moving the mouse to the middle of an element.
:Args:
- to_element: The WebElement to move to.
"""
if self._driver.w3c:
self.w3c_actions.pointer_action.move_to(to_element)
self.w3c_actions.key_action.pause()
else:
self._actions.append(lambda: self._driver.execute(
Command.MOVE_TO， {'element': to_element.id}))
return self
def move_to_element_with_offset(self， to_element， xoffset， yoffset):
"""
Move the mouse by an offset of the specified element.
Offsets are relative to the top-left corner of the element.
:Args:
- to_element: The WebElement to move to.
- xoffset: X offset to move to.
- yoffset: Y offset to move to.
"""
if self._driver.w3c:
self.w3c_actions.pointer_action.move_to(to_element， xoffset， yoffset)
self.w3c_actions.key_action.pause()
else:
self._actions.append(
lambda: self._driver.execute(Command.MOVE_TO， {
'element': to_element.id，
'xoffset': int(xoffset)，
'yoffset': int(yoffset)}))
return self
def release(self， on_element=None):
"""