Objective-C：检查是否使用枚举选项 [英] Objective-C: Check if using enum option

问题描述

我有一个使用typedef枚举的自定义对象。如果我为我的对象设置了一些枚举选项，我该如何检查它们是否被使用？

I have a custom object that is using a typedef enum. If I set a few of the enum options for my object, how can I check to see if those are being used?

typedef enum {
    Option1,
    Option2,
    Option3
} Options;

创建我的对象时我可能会使用：

When creating my object I might use:

myobject.options = Option1 | Option2;

我如何稍后检查哪些枚举选项已设置？如：

How can I then later check which enum options were set? Such as:

if (myobject.options == Option1) {
  // Do something
}

if (myobject.options == Option2) {
  // Do something
}

推荐答案

如果要为options参数执行按位逻辑，则应定义枚举，以便每个选项只设置一个位：

If you want to do bitwise logic for your options parameter, then you should define your enum so that each option only has a single bit set:

typedef enum {
    Option1 = 1,       // 00000001
    Option2 = 1 << 1,  // 00000010
    Option3 = 1 << 2   // 00000100
} Options;

然后使用按位OR运算符设置选项：

Then you set your options using the bitwise OR operator:

myObject.options = Option1 | Option2;

并检查使用按位AND运算符设置的选项：

and check which options have been set using the bitwise AND operator:

if(myObject.options & Option1) {
    // Do something
}

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