Objective- C - 循环遍历类中的所有属性? [英] Objective- C - Looping through all properties in a class?

问题描述

有没有办法遍历对象中的所有属性并获取它们的名称"和值".

Is there a way to loop through all properties in an object and get their "name" and "value".

我正在尝试编写一个类别，根据对象的属性名称和值将对象序列化为字符串.我试图阻止为每个类编写编码方法，而是编写一个通用的方法.

I am trying to write a category to serialize objects to a string, based on their property name and values. I'm trying to prevent writing encoding methods for each class, and instead write a generic one.

这可能吗?

推荐答案

您可以使用此代码枚举类中声明的所有属性，以及这些属性的所有属性.我猜你对解析 type 属性更感兴趣.它们在此处有详细说明.

You can use this code to enumerate all properties declared in a class, and all attributes of the properties. I guess you're more interested in parsing the type attribute. They are detailed here.

unsigned int numOfProperties;
objc_property_t *properties = class_copyPropertyList([self class], &numOfProperties);
for ( unsigned int pi = 0; pi < numOfProperties; pi++ ) {
    // Examine the property attributes
    unsigned int numOfAttributes;
    objc_property_attribute_t *propertyAttributes = property_copyAttributeList(properties[pi], &numOfAttributes);
    for ( unsigned int ai = 0; ai < numOfAttributes; ai++ ) {
        switch (propertyAttributes[ai].name[0]) {
            case 'T': // type
                break;
            case 'R': // readonly
                break;
            case 'C': // copy 
                break;
            case '&': // retain
                break;
            case 'N': // nonatomic 
                break;
            case 'G': // custom getter
                break;
            case 'S': // custom setter
                break;
            case 'D': // dynamic 
                break;
            default: 
                break;
        }
    }
    free(propertyAttributes);
}
free(properties);

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