【Appium_python】启动app,出现多次打开关闭导致失败问题，driver用单例模式（_new_）进行解决。

运用多设备，启动app多次出现打开又关闭问题，查看后是多次对driver进行实例化，就用单例的模式进行解决。

单例模式（Singleton Pattern）目的就是保证一个类仅有一个实例，每一次执行类名返回的对象，内存地址是相同的。

根据编写的代码特点就使用_new_方法实现

from appium import webdriver
from util.write_user_command import WriteUserCommand

class Singleton(object):
    driver = None

    def __new__(cls, i, *args, **kwargs):
        if not hasattr(cls, '_instance'):
            orig = super(Singleton, cls)
            write_file = WriteUserCommand()
            devices = write_file.get_value('user_info_' + str(i), 'deviceName')
            port = write_file.get_value('user_info_' + str(i), 'port')
            desired_caps = dict()
            desired_caps['platformName'] = 'Android'
            desired_caps['automationName'] = 'UiAutomator2'
            # 接受中文输入
            # desired_caps['unicodeKeyboard'] = True
            # desired_caps['resetKeyboard'] = True
            desired_caps['noReset'] = True
            desired_caps['deviceName'] = devices
            desired_caps['app'] = 'D:\\Projects\\PycharmProjects\\plum\\apk\\xxxtV5.2.7.4_release.apk'
            desired_caps['appPackage'] = 'xx_package_name'
            # desired_caps['appWaitActivity'] = ''等到某个activity才去执行
            desired_caps['appActivity'] = '.xxxappActivity.WelcomeActivity'
            cls._instance = orig.__new__(cls, *args, **kwargs)
            cls._instance.driver = webdriver.Remote("http://127.0.0.1:" + str(port) + "/wd/hub", desired_caps)

        return cls._instance

    def __init__(self, i, *args, **kwargs):
        self.i = i

class BaseDriver(Singleton):
    def get_driver(self):
        return self.driver

if __name__ == '__main__':
    # driver = BaseDriver().get_driver()
    # appium -p 4725 -bp 4701 -U 127.0.0.1:21503(devices_name)
    pass

大致就是这样，涉及到别的从别的配置文件读取多设备的配置信息就不介绍了。