Makes the execution of a method dependent on a preprocessing identifier 根据预处理标识符执行方法。
2.
A string that specifies the case - sensitive conditional compilation symbol associated with the attribute 一个包含预处理标识符的字符串,该字符串使当前实例的目标方法可以被调用。
3.
Indicates to compilers that a method call or attribute should be ignored unless a specified conditional compilation symbol is defined 向编译器指示,如果将指定预处理标识符应用到一个方法,则该方法是可调用的。