Selenium Chrome移动端模拟触摸功能失效，如何启用该功能？

用Selenium模拟Chrome移动端时，我配置了如下设备参数来启用触摸功能：

"deviceMetrics" => { "width" => 360, "height" => 640, "pixelRatio" => 3.0, touch: true }

代码能正常运行，但触摸功能完全失效——没法进行触摸、滑动操作，也触发不了任何触摸事件。感觉原来的触摸配置方式可能被弃用了，求正确启用触摸功能的方法。

我用Ruby和Python编写代码，Python环境信息：

• Python 3.7.7
• selenium 4.11.2
• selenium-wire 5.1.0
• Chrome 116.0.5845.187
• ChromeDriver 116.0.5845.96

Python代码示例：

mobile_emulation = {
    "deviceMetrics": { "width": 360, "height": 640, "pixelRatio": 3.0, "touch": True, "mobile": True },
    "userAgent": "Mozilla/5.0 (Linux; Android 11; SM-G977U Build/RP1A.200720.012; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/83.0.4103.106 Mobile Safari/537.36",
    "clientHints": {"platform": "Android", "mobile": True} }

chrome_options = Options()
chrome_options.add_experimental_option("mobileEmulation", mobile_emulation)
chrome_options.add_experimental_option("detach",True)

driver = webdriver.Chrome(chrome_options = chrome_options)

1. 直接用Chrome预设的移动设备名称 #

Chrome内置了大量成熟的移动设备配置，直接指定设备名就能自动启用触摸功能，比手动配置参数更可靠：

from selenium import webdriver
from selenium.webdriver.chrome.options import Options

chrome_options = Options()
# 这里以Galaxy S20为例，也可替换为"iPhone 13"等其他预设设备名
chrome_options.add_experimental_option("mobileEmulation", {"deviceName": "Galaxy S20"})
chrome_options.add_experimental_option("detach", True)

driver = webdriver.Chrome(options=chrome_options)

2. 用CDP命令强制开启触摸模拟 #

如果必须手动配置设备参数，新版本Chrome仅在deviceMetrics里设置touch: true已经不生效，需要额外通过Chrome DevTools协议命令开启触摸：

from selenium import webdriver
from selenium.webdriver.chrome.options import Options

mobile_emulation = {
    "deviceMetrics": { "width": 360, "height": 640, "pixelRatio": 3.0 },
    "userAgent": "Mozilla/5.0 (Linux; Android 11; SM-G977U Build/RP1A.200720.012; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/83.0.4103.106 Mobile Safari/537.36",
    "clientHints": {"platform": "Android", "mobile": True}
}

chrome_options = Options()
chrome_options.add_experimental_option("mobileEmulation", mobile_emulation)
chrome_options.add_experimental_option("detach", True)

driver = webdriver.Chrome(options=chrome_options)
# 执行CDP命令启用触摸，maxTouchPoints设为5模拟真实手机的多点触摸
driver.execute_cdp_cmd("Emulation.setTouchEmulationEnabled", {"enabled": True, "maxTouchPoints": 5})

3. 排查selenium-wire的影响 #

你使用了selenium-wire代理工具，它有可能干扰Chrome的触摸配置。可以先移除selenium-wire，用原生webdriver测试，确认是否是代理导致的触摸功能失效。

Ruby版本对应的解决代码 #

如果是用Ruby编写的代码，同样可以通过CDP命令开启触摸：

require 'selenium-webdriver'

mobile_emulation = {
  "deviceMetrics" => { "width" => 360, "height" => 640, "pixelRatio" => 3.0 },
  "userAgent" => "Mozilla/5.0 (Linux; Android 11; SM-G977U Build/RP1A.200720.012; wv) AppleWebKit/537.36 (KHTML, like Gecko) Version/4.0 Chrome/83.0.4103.106 Mobile Safari/537.36",
  "clientHints" => {"platform" => "Android", "mobile" => true}
}

options = Selenium::WebDriver::Chrome::Options.new
options.add_experimental_option("mobileEmulation", mobile_emulation)
options.add_experimental_option("detach", true)

driver = Selenium::WebDriver.for :chrome, options: options
# 启用触摸模拟
driver.execute_cdp('Emulation.setTouchEmulationEnabled', enabled: true, maxTouchPoints: 5)

内容的提问来源于stack exchange，提问作者GokuSleepy