它的目的是避免使用空子符串调用Web服务而出现空指针异常。

This code is included in the code which handles the click event for the Invoke Service button and its purpose is to avoid a null pointer exception when the web service is invoked with an empty string.

youdao

它的目的是避免使用空子符串调用Web服务而出现空指针异常。

This code is included in the code which handles the click event for the Invoke Service button and its purpose is to avoid a null pointer exception when the web service is invoked with an empty string.

youdao