如何定义和在Objective-C使用ENUM？ [英] How do I define and use an ENUM in Objective-C?

问题描述

我宣布我实现文件的枚举，如下图所示，并宣称该类型在我的界面PlayerState thePlayerState的变量;和所用的变量在我的方法。但我得到的错误，指出它是未申报。我该如何正确申报，并在我的方法使用类型PlayerState的变量：

在.m文件

  @implementation View1Controller    的typedef枚举playerStateTypes
        {
            PLAYER_OFF，
            PLAYER_PLAYING，
            PLAYER_PAUSED
        } PlayerState;
 

在.h文件中：

  @interface View1Controller：{的UIViewController    PlayerState thePlayerState;
 

在.m文件的一些方法：

   - （无效）{doSomethinthePlayerState = PLAYER_OFF;}
 

解决方案

您的typedef 需要在头文件（或其他文件中的＃进口编入你的头），否则编译器将不知道做什么尺寸 PlayerState 伊娃。除此之外，它看起来不错我。

I declared an enum in my implementation file as shown below, and declared a variable of that type in my interface as PlayerState thePlayerState; and used the variable in my methods. But I am getting errors stating that it is undeclared. How do I correctly declare and use a variable of type PlayerState in my methods?:

In the .m file

@implementation View1Controller

    typedef enum playerStateTypes
        {
            PLAYER_OFF,
            PLAYER_PLAYING,
            PLAYER_PAUSED
        } PlayerState;

in the .h file:

@interface View1Controller : UIViewController {

    PlayerState thePlayerState;

in some method in .m file:

-(void)doSomethin{

thePlayerState = PLAYER_OFF;

}

解决方案

Your typedef needs to be in the header file (or some other file that's #imported into your header), because otherwise the compiler won't know what size to make the PlayerState ivar. Other than that, it looks ok to me.

这篇关于如何定义和在Objective-C使用ENUM？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！