> 通過本篇你講瞭解到Airtest是如何跟安卓設備交互的，以及多設備時的多機交互使用。
在之前從Touch接口分析Airtest的圖像識別中，在圖像識別獲取到目標位置以後，發起點擊的操作是通過以下這句：
`G.DEVICE.touch(pos, **kwargs)`
看一下有那麼多個類裏有touch接口，device、minitouch、adb、android、win、linux、ios
另外再翻一下airtest.core.api這個文件裏的其他接口
```
"""
Device Operations
"""
@logwrap
def shell(cmd):
"""
Start remote shell in the target device and execute the command
:param cmd: command to be run on device, e.g. "ls /data/local/tmp"
:return: the output of the shell cmd
:platforms: Android
"""
return G.DEVICE.shell(cmd)
@logwrap
def start_app(package, activity=None):
"""
Start the target application on device
:param package: name of the package to be started, e.g. "com.netease.my"
:param activity: the activity to start, default is None which means the main activity
:return: None
:platforms: Android, iOS
"""
G.DEVICE.start_app(package, activity)
```
可見，這些設備操作的接口都是通過這個**G.DEVICE**，所以這裏就是我們要找的Airtest與各類被測設備交互的實現部分了。
先來看一下這個G.DEVICE是什麼
```
class G(object):
"""Represent the globals variables"""
BASEDIR = []
LOGGER = AirtestLogger(None)
LOGGING = get_logger("airtest.core.api")
SCREEN = None
DEVICE = None
DEVICE_LIST = []
RECENT_CAPTURE = None
RECENT_CAPTURE_PATH = None
CUSTOM_DEVICES = {}
@classmethod
def add_device(cls, dev):
"""
Add device instance in G and set as current device.
Examples:
G.add_device(Android())
Args:
dev: device to init
Returns:
None
"""
cls.DEVICE = dev
cls.DEVICE_LIST.append(dev)
```
看這個add_device的註釋，傳入的dev是初始化之後的設備對象，例如安卓，ios等，然後存放在G.DEVICE和添加到G.DEVICE_LIST列表裏。既然是初始化，那麼想必就是要在腳本的最前面的執行吧，所以Airtest新建腳本時自動生成的那句auto_setup應該就跟設備初始化有關係了，一起去看看。
```
def auto_setup(basedir=None, devices=None, logdir=None, project_root=None):
"""
Auto setup running env and try connect android device if not device connected.
"""
if devices:
for dev in devices:
connect_device(dev)
elif not G.DEVICE_LIST:
try:
connect_device("Android:///")
except IndexError:
pass
if basedir:
if os.path.isfile(basedir):
basedir = os.path.dirname(basedir)
if basedir not in G.BASEDIR:
G.BASEDIR.append(basedir)
if logdir:
set_logdir(logdir)
if project_root:
ST.PROJECT_ROOT = project_root
def connect_device(uri):
"""
Initialize device with uri, and set as current device.
:param uri: an URI where to connect to device, e.g. `android://adbhost:adbport/serialno?param=value¶m2=value2`
:return: device instance
:Example:
* ``android:///`` # local adb device using default params
* ``android://adbhost:adbport/1234566?cap_method=javacap&touch_method=adb`` # remote device using custom params
* ``windows:///`` # local Windows application
* ``ios:///`` # iOS device
"""
d = urlparse(uri)
platform = d.scheme
host = d.netloc
uuid = d.path.lstrip("/")
params = dict(parse_qsl(d.query))
if host:
params["host"] = host.split(":")
dev = init_device(platform, uuid, **params)
return dev
def init_device(platform="Android", uuid=None, **kwargs):
"""
Initialize device if not yet, and set as current device.
:param platform: Android, IOS or Windows
:param uuid: uuid for target device, e.g. serialno for Android, handle for Windows, uuid for iOS
:param kwargs: Optional platform specific keyword args, e.g. `cap_method=JAVACAP` for Android
:return: device instance
"""
cls = import_device_cls(platform)
dev = cls(uuid, **kwargs)
for index, instance in enumerate(G.DEVICE_LIST):
if dev.uuid == instance.uuid:
G.LOGGING.warn("Device:%s updated %s -> %s" % (dev.uuid, instance, dev))
G.DEVICE_LIST[index] = dev
break
else:
G.add_device(dev)
return dev
def import_device_cls(platform):
"""lazy import device class"""
platform = platform.lower()
if platform in G.CUSTOM_DEVICES:
cls = G.CUSTOM_DEVICES[platform]
elif platform == "android":
from airtest.core.android.android import Android as cls
elif platform == "windows":
from airtest.core.win.win import Windows as cls
elif platform == "ios":
from airtest.core.ios.ios import IOS as cls
elif platform == "linux":
from airtest.core.linux.linux import Linux as cls
else:
raise RuntimeError("Unknown platform: %s" % platform)
return cls
```
由上到下的調用關係：auto_setup -> connect_device -> init_device -> add_device
auto_setup接口：依次連接全部設備，處理日誌，工程根目錄等事物
connect_device接口：根據傳入參數uri的解析出其平臺和序列號信息，然後初始化設備
init_device接口：調用import_device_cls導入不同的平臺，初始化設備對象，如果DEVICE_LIST列表裏沒有該設備，則添加設備
add_device接口：將新連接上的設備賦值給G.DEVICE，添加到G.DEVICE_LIST
所以在Airtest教程中的“4.3 多機協作腳本”講到：
> 在我們的腳本中，支持通過set_current接口來切換當前連接的手機，因此我們一個腳本中，是能夠調用多臺手機，編寫出一些複雜的多機交互腳本的。
> 在命令行運行腳本時，只需要將手機依次使用--device Android:///添加到命令行中即可，例如：
> >airtest run untitled.air --device Android:///serialno1 --device Android:///serialno2 --device
在之前的筆記裏分析過run_script接口解析命令行參數中的device會生成成一個設備列表，傳入到auto_setup裏就會遍歷列表逐個去連接，所以多設備交互的操作是：
1.初始化連接所有的設備——命令行或者是調用run_script傳入多個設備，當然也可以直接調用connect_device、add_device;
2.調用set_current來切換當前操作的設備。
set_current接口很簡單了，在G.DEVICE_LIST裏找出目標設備，賦值給G.DEVICE，因爲對設備的操作都是通過G.DEVICE的，所以只要換掉G.DEVICE就完成了設備的切換。看下源碼：
```
def set_current(idx):
"""
Set current active device.
:param idx: uuid or index of initialized device instance
:raise IndexError: raised when device idx is not found
:return: None
:platforms: Android, iOS, Windows
"""
dev_dict = {dev.uuid: dev for dev in G.DEVICE_LIST}
if idx in dev_dict:
current_dev = dev_dict[idx]
elif isinstance(idx, int) and idx < len(G.DEVICE_LIST):
current_dev = G.DEVICE_LIST[idx]
else:
raise IndexError("device idx not found in: %s or %s" % (
list(dev_dict.keys()), list(range(len(G.DEVICE_LIST)))))
G.DEVICE = current_dev
```
關於Airtest的設備管理的分析大概就是以上這些了，多設備的交互很簡單，不用在具體的操作方法中指定設備，而是隻用在中間調用set_current來完成切換設備，例如切換前是A設備，那麼所有的操作都會指向A設備，切換後則都指向B設備，這種設計也挺省事的。
接下來再拿android這部分來看一下airtest是怎麼跟設備交互的。
從import_device_cls接口裏找進去
'elif platform == "android": from airtest.core.android.android import Android as cls'
android平臺的設備管理在airtest.core.android.android的Android類裏
```
class Android(Device):
"""Android Device Class"""
def __init__(self, serialno=None, host=None,
cap_method=CAP_METHOD.MINICAP_STREAM,
touch_method=TOUCH_METHOD.MINITOUCH,
ime_method=IME_METHOD.YOSEMITEIME,
ori_method=ORI_METHOD.MINICAP,
):
super(Android, self).__init__()
self.serialno = serialno or self.get_default_device()
self.cap_method = cap_method.upper()
self.touch_method = touch_method.upper()
self.ime_method = ime_method.upper()
self.ori_method = ori_method.upper()
# init adb
self.adb = ADB(self.serialno, server_addr=host)
self.adb.wait_for_device()
self.sdk_version = self.adb.sdk_version
self._display_info = {}
self._current_orientation = None
# init components
self.rotation_watcher = RotationWatcher(self.adb)
self.minicap = Minicap(self.adb, ori_function=self.get_display_info)
self.javacap = Javacap(self.adb)
self.minitouch = Minitouch(self.adb, ori_function=self.get_display_info)
self.yosemite_ime = YosemiteIme(self.adb)
self.recorder = Recorder(self.adb)
self._register_rotation_watcher()
```
Android是安卓設備類，父類是Device,這是一個基類，只定義了設備通用接口。android設備初始化，初始化adb，初始化minicap、javacap、minitouch、yosemite、recorder等組件。
翻一下Android類的接口，全都是對安卓設備的操作，基本的一些操作是通過adb完成的，比如：啓動應用，卸載應用，喚醒...
```
def start_app(self, package, activity=None):
"""
Start the application and activity
Args:
package: package name
activity: activity name
Returns:
None
"""
return self.adb.start_app(package, activity)
def unlock(self):
"""
Unlock the device
Notes:
Might not work on all devices
Returns:
None
"""
return self.adb.unlock()
```
還有就是用到了其他組件的操作了，比如截圖用到minicap和javacap組件，截圖有四種方式：minicap_stream、minicap、javacap、adb_snapshot，初始化傳入參數可配置截圖的方式，默認是MINICAP_STREAM，截圖之後就是寫入，轉換成cv2的格式，處理橫豎屏的轉換。
```
def snapshot(self, filename=None, ensure_orientation=True):
"""
Take the screenshot of the display. The output is send to stdout by default.
Args:
filename: name of the file where to store the screenshot, default is None which si stdout
ensure_orientation: True or False whether to keep the orientation same as display
Returns:
screenshot output
"""
"""default not write into file."""
if self.cap_method == CAP_METHOD.MINICAP_STREAM:
self.rotation_watcher.get_ready()
screen = self.minicap.get_frame_from_stream()
elif self.cap_method == CAP_METHOD.MINICAP:
screen = self.minicap.get_frame()
elif self.cap_method == CAP_METHOD.JAVACAP:
screen = self.javacap.get_frame_from_stream()
else:
screen = self.adb.snapshot()
# output cv2 object
try:
screen = aircv.utils.string_2_img(screen)
except Exception:
# may be black/locked screen or other reason, print exc for debugging
import traceback
traceback.print_exc()
return None
# ensure the orientation is right
if ensure_orientation and self.display_info["orientation"]:
# minicap screenshots are different for various sdk_version
if self.cap_method in (CAP_METHOD.MINICAP, CAP_METHOD.MINICAP_STREAM) and self.sdk_version <= 16:
h, w = screen.shape[:2] # cvshape是高度在前面!!!!
if w < h: # 當前是橫屏，但是圖片是豎的，則旋轉，針對sdk<=16的機器
screen = aircv.rotate(screen, self.display_info["orientation"] * 90, clockwise=False)
# adb 截圖總是要根據orientation旋轉
elif self.cap_method == CAP_METHOD.ADBCAP:
screen = aircv.rotate(screen, self.display_info["orientation"] * 90, clockwise=False)
if filename:
aircv.imwrite(filename, screen)
return screen
```
輸入字符用到yosemite輸入法，在yosemite初始化時會往安卓設備中安裝一個叫yosemite的輸入法app，並通過adb命令將設備的當前輸入法切換成yosemite，yosemite輸入法app有個廣播接收器，接收到廣播後輸入字符。
`self.yosemite_ime = YosemiteIme(self.adb)`
```
class YosemiteIme(CustomIme):
"""
Yosemite Input Method Class Object
"""
def __init__(self, adb):
super(YosemiteIme, self).__init__(adb, None, YOSEMITE_IME_SERVICE)
self.yosemite = Yosemite(adb)
def start(self):
self.yosemite.get_ready()
super(YosemiteIme, self).start()
def text(self, value):
"""
Input text with Yosemite input method
Args:
value: text to be inputted
Returns:
output form `adb shell` command
"""
if not self.started:
self.start()
# 更多的輸入用法請見 https://github.com/macacajs/android-unicode#use-in-adb-shell
value = ensure_unicode(value)
self.adb.shell(u"am broadcast -a ADB_INPUT_TEXT --es msg '{}'".format(value))
```
```
def start(self):
"""
Enable input method
Returns:
None
"""
try:
self.default_ime = self.adb.shell("settings get secure default_input_method").strip()
except AdbError:
# settings cmd not found for older phones, e.g. Xiaomi 2A
# /system/bin/sh: settings: not found
self.default_ime = None
self.ime_list = self._get_ime_list()
if self.service_name not in self.ime_list:
if self.apk_path:
self.device.install_app(self.apk_path)
if self.default_ime != self.service_name:
self.adb.shell("ime enable %s" % self.service_name)
self.adb.shell("ime set %s" % self.service_name)
self.started = True
```
所以輸入字符的接口也有兩種方式：yosemite輸入法和adb命令，默認是yosemite輸入
```
def text(self, text, enter=True):
"""
Input text on the device
Args:
text: text to input
enter: True or False whether to press `Enter` key
Returns:
None
"""
if self.ime_method == IME_METHOD.YOSEMITEIME:
self.yosemite_ime.text(text)
else:
self.adb.shell(["input", "text", text])
# 遊戲輸入時，輸入有效內容後點擊Enter確認，如不需要，enter置爲False即可。
if enter:
self.adb.shell(["input", "keyevent", "ENTER"])
```
錄屏用到recorder組件，錄屏是用yosemite這個app實現的，pythod這邊只是發adb命令，簡單的看一下start_record這部分吧，
```
源碼位置：airtest/core/android/android.py
def start_recording(self, *args, **kwargs):
"""
Start recording the device display
Args:
*args: optional arguments
**kwargs: optional arguments
Returns:
None
"""
return self.recorder.start_recording(*args, **kwargs)
```
```
源碼位置：airtest/core/android/recorder.py
@on_method_ready('install_or_upgrade')
def start_recording(self, max_time=1800, bit_rate=None, vertical=None):
"""
Start screen recording
Args:
max_time: maximum rate value, default is 1800
bit_rate: bit rate value, default is None
vertical: vertical parameters, default is None
Raises:
RuntimeError: if any error occurs while setup the recording
Returns:
None if recording did not start, otherwise True
"""
if getattr(self, "recording_proc", None):
raise AirtestError("recording_proc has already started")
pkg_path = self.adb.path_app(YOSEMITE_PACKAGE)
max_time_param = "-Dduration=%d" % max_time if max_time else ""
bit_rate_param = "-Dbitrate=%d" % bit_rate if bit_rate else ""
if vertical is None:
vertical_param = ""
else:
vertical_param = "-Dvertical=true" if vertical else "-Dvertical=false"
p = self.adb.start_shell('CLASSPATH=%s exec app_process %s %s %s /system/bin %s.Recorder --start-record' %
(pkg_path, max_time_param, bit_rate_param, vertical_param, YOSEMITE_PACKAGE))
nbsp = NonBlockingStreamReader(p.stdout)
while True:
line = nbsp.readline(timeout=5)
if line is None:
raise RuntimeError("start recording error")
if six.PY3:
line = line.decode("utf-8")
m = re.match("start result: Record start success! File path:(.*\.mp4)", line.strip())
if m:
output = m.group(1)
self.recording_proc = p
self.recording_file = output
return True
```
點擊、滑動等用到minitouch組件，同樣的可選minitouch或者是adb
```
def touch(self, pos, duration=0.01):
"""
Perform touch event on the device
Args:
pos: coordinates (x, y)
duration: how long to touch the screen
Returns:
None
"""
if self.touch_method == TOUCH_METHOD.MINITOUCH:
pos = self._touch_point_by_orientation(pos)
self.minitouch.touch(pos, duration=duration)
else:
self.adb.touch(pos)
```
minitouch、minicap有啥不同呢，這是openstf的庫，大概是在安卓設備下放了一個client，pythod這邊用safesocket發消息給client，由client執行操作，詳細的先不在這裏分析了。
android設備類大致就是這樣了，再往下可以看看adb類，這個就只看看發命令的核心接口吧。
```
def start_cmd(self, cmds, device=True):
"""
Start a subprocess with adb command(s)
Args:
cmds: command(s) to be run
device: if True, the device serial number must be specified by `-s serialno` argument
Raises:
RuntimeError: if `device` is True and serialno is not specified
Returns:
a subprocess
"""
if device:
if not self.serialno:
raise RuntimeError("please set serialno first")
cmd_options = self.cmd_options + ['-s', self.serialno]
else:
cmd_options = self.cmd_options
cmds = cmd_options + split_cmd(cmds)
LOGGING.debug(" ".join(cmds))
if not PY3:
cmds = [c.encode(get_std_encoding(sys.stdin)) for c in cmds]
proc = subprocess.Popen(
cmds,
stdin=subprocess.PIPE,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE
)
return proc
```
總結，Airtest的設備管理只是用G.DEVICE指向當前設備，用G.DEVICE_LIST保存全部設備，所有的操作都通過G.DEVICE轉發，所以改變G.DEVICE即可切換設備。而安卓設備的交互則是通過adb命令，和一些別的庫:yosemete、minitouch、minicap、javacap。