performSelector may cause a leak because its selector is unknown

代码如下:

当target不清晰的情况下会出现 “PerformSelector may cause a leak because its selector is unknown” 警告

NSObject *target = parameters[@"target"];
NSString *selectorString = parameters[@"selector"];
[target performSelector:NSSelectorFromString(selectorString) withObject:nil];      

可以用以下代码代替，消除警告

SEL selector = NSSelectorFromString(selectorString);
IMP imp = [target methodForSelector:selector];
void (*func)(id, SEL ,NSDictionary *json) = (void *)imp;
func(target ,selector ,@{});