我尝试通过直接连接使用 adb，即通过端口 5037 使用 telnet，基本命令（如“host:devices”）返回与等效 adb 命令相同的答案：
C:\adb>adb devices
List of devices attached
4d009c06c8459000 device
C:\adb>telnet localhost 5037
Connecting to localhost...
Sent: 000Chost:devices
Received: OKAY00184d009c06c8459000 device
但是当我尝试像“shell”这样的“设备”命令时，我收到错误：
C:\adb>adb shell ls
acct
cache
charger
config
...
...
C:\adb>telnet localhost 5037
Connecting to localhost...
Sent: 0008shell:ls
Received: FAIL0012device offline (x)
怎么了？