最新消息:20210816 当前crifan.com域名已被污染,为防止失联,请关注(页面右下角的)公众号

[已解决]Swift代码出错:Use of unresolved identifier NSAssert

Swift crifan 6052浏览

[背景]

想要把OC代码:

1
NSAssert(newViewControllers.count >= 2, "MHTabBarController requires at least two view controllers")

转换为swift代码,结果出错:

Use of unresolved identifier ‘NSAssert’

如图:

Use of unresolved identifier NSAssert

[解决过程]

1.搜:

swift Use of unresolved identifier NSAssert

swift  NSAssert

参考:

Transitioning from Objective-C to Swift | b2cloud

去改为:

1
assert(newViewControllers.count >= 2, "MHTabBarController requires at least two view controllers")

即可通过编译。

[总结]

OC中,加了断言,当条件不满足时,编译期间会出错。但是当实际运行时,断言是没用的;

-》换言之:当编译为实际运行的app时,NSAssert都被去掉了。

而Swift中,其实也是类似的:

NSAssert被换为assert,也只是编译期间有用,运行时也已经被去掉了;

而OC中的NSAssert,Swift中改为了assert

并且,字符串之前加的@符号,也不需要了。

转载请注明:在路上 » [已解决]Swift代码出错:Use of unresolved identifier NSAssert

84 queries in 0.191 seconds, using 19.13MB memory