本篇转自博客：上海-悠悠
前言
appium1.5以后的版本才支持toast定位，并且 'automationName'得设置为'Uiautomator2'，才能捕获到。
一、 Supported Platforms
1.查看appium v1.7版本[官方文档](https://github.com/appium/appium/)
**Supported Platforms**
Appium supports app automation across a variety of platforms, like iOS, Android, and Windows. Each platform is supported by one or more "drivers", which know how to automate that particular platform. Choose a driver below for specific information about how that driver works and how to set it up:
- iOS
- The [XCUITest Driver]
- (DEPRECATED) The [UIAutomation Driver]
- Android
- (BETA) The [Espresso Driver]
- The [UiAutomator2 Driver]
- (DEPRECATED) The [UiAutomator Driver]
- (DEPRECATED) The [Selendroid Driver]
- The [Windows Driver](for Windows Desktop apps)
- The [Mac Driver] (for Mac Desktop apps)
2.从上面的信息可以看出目前1.7的android版可以支持：Espresso、UiAutomator2、UiAutomator、Selendroid四种驱动模式，后面两个不推荐用了，太老了，Espresso这个是最新支持的处于beta阶段，UiAutomator2是目前最稳的。
3.appium最新版本还能支持windows和mac的桌面app程序了，这个是否稳定，拭目以待！
二、 toast定位
1.先看下toast长什么样，如下图，像这种弹出来的消息"再按一次退出",这种就是toast了。
2.想定位toast元素，这里一定要注意automationName的参数必须是Uiautomator2才能定位到。
> 'automationName': 'Uiautomator2'
```
# coding:utf-8
from appium import webdriver
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
from time import sleep
desired_caps = {
'platformName': 'Android',
'deviceName': '127.0.0.1:62001',
'platformVersion': '4.4.2',
'appPackage': 'com.baidu.yuedu',
'appActivity': 'com.baidu.yuedu.splash.SplashActivity',
'noReset': 'true',
'automationName': 'Uiautomator2'
}
driver = webdriver.Remote('http://127.0.0.1:4723/wd/hub', desired_caps)
# 等主页面activity出现
driver.wait_activity(".base.ui.MainActivity", 10)
driver.back() # 点返回
# 定位toast元素
toast_loc = ("xpath", ".//*[contains(@text,'再按一次退出')]")
t = WebDriverWait(driver, 10, 0.1).until(EC.presence_of_element_located(toast_loc))
print t
```
3.打印出来的结果，出现如下信息，说明定位到toast了
><appium.webdriver.webelement.webelement session="02813cce-9aaf-4754-a532-07ef7aebeb88" element="339f72c4-d2e0-4d98-8db0-69be741a3d1b"></appium.webdriver.webelement.webelement>
三、 封装toast判断
1.单独写一个函数来封装判断是否存在toast消息，存在返回True,不存在返回False
```
def is_toast_exist(driver,text,timeout=30,poll_frequency=0.5):
'''is toast exist, return True or False
:Agrs:
- driver - 传driver
- text - 页面上看到的文本内容
- timeout - 最大超时时间，默认30s
- poll_frequency - 间隔查询时间，默认0.5s查询一次
:Usage:
is_toast_exist(driver, "看到的内容")
'''
try:
toast_loc = ("xpath", ".//*[contains(@text,'%s')]"%text)
WebDriverWait(driver, timeout, poll_frequency).until(EC.presence_of_element_located(toast_loc))
return True
except:
return False
```
四、 参考代码
```
# coding:utf-8
from appium import webdriver
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC
desired_caps = {
'platformName': 'Android',
'deviceName': '127.0.0.1:62001',
'platformVersion': '4.4.2',
'appPackage': 'com.baidu.yuedu',
'appActivity': 'com.baidu.yuedu.splash.SplashActivity',
'noReset': 'true',
'automationName': 'Uiautomator2'
}
def is_toast_exist(driver,text,timeout=30,poll_frequency=0.5):
'''is toast exist, return True or False
:Agrs:
- driver - 传driver
- text - 页面上看到的文本内容
- timeout - 最大超时时间，默认30s
- poll_frequency - 间隔查询时间，默认0.5s查询一次
:Usage:
is_toast_exist(driver, "看到的内容")
'''
try:
toast_loc = ("xpath", ".//*[contains(@text,'%s')]"%text)
WebDriverWait(driver, timeout, poll_frequency).until(EC.presence_of_element_located(toast_loc))
return True
except:
return False
if __name__ == "__main__":
driver = webdriver.Remote('http://127.0.0.1:4723/wd/hub', desired_caps)
# 等主页面activity出现
driver.wait_activity(".base.ui.MainActivity", 10)
driver.back() # 点返回
# 判断是否存在toast-'再按一次退出'
print is_toast_exist(driver, "再按一次退出")
```