Ray's playground

摘要： To generate one of the so-called selectors listed in Table 9.1, you apply the @selectordirective to a method name. For example, the following produces a value of type SEL forthe method named alloc, wh... 阅读全文

摘要： Using the @class directive is more efficient because the compiler doesn’t need toprocess the entire XYPoint.h file (even though it is quite small); it just needs to know thatXYPoint is the name ... 阅读全文