我想知道是否可以确定对象属性的类或原始类型.获取所有属性名称和值非常简单.
SO answer
示例代码
@interface MyObject : NSObject
@property (nonatomic,copy) NSString *aString;
@property (nonatomic,copy) NSDate *aDate;
@property NSInteger aPrimitive;
@end
@implementation MyObject
@synthesize aString;
@synthesize aDate;
@synthesize aPrimitive;
- (void)getTheTypesOfMyProperties {
unsigned int count;
objc_property_t* props = class_copyPropertyList([self class],&count);
for (int i = 0; i < count; i++) {
objc_property_t property = props[i];
// Here I can easy get the name or value
const char * name = property_getName(property);
// But is there any magic function that can tell me the type?
// the property can be nil at this time
Class cls = magicFunction(property);
}
free(props);
}
@end
解决方法
通过
Apples Documentation about objc Runtime搜索,根据
this SO answer,我终于得到了工作.我只是想分享我的结果.
unsigned int count;
objc_property_t* props = class_copyPropertyList([MyObject class],&count);
for (int i = 0; i < count; i++) {
objc_property_t property = props[i];
const char * name = property_getName(property);
NSString *propertyName = [NSString stringWithCString:name encoding:NSUTF8StringEncoding];
const char * type = property_getAttributes(property);
NSString *attr = [NSString stringWithCString:type encoding:NSUTF8StringEncoding];
NSString * typeString = [NSString stringWithUTF8String:type];
NSArray * attributes = [typeString componentsSeparatedByString:@","];
NSString * typeAttribute = [attributes objectAtIndex:0];
NSString * propertyType = [typeAttribute substringFromIndex:1];
const char * rawPropertyType = [propertyType UTF8String];
if (strcmp(rawPropertyType,@encode(float)) == 0) {
//it's a float
} else if (strcmp(rawPropertyType,@encode(int)) == 0) {
//it's an int
} else if (strcmp(rawPropertyType,@encode(id)) == 0) {
//it's some sort of object
} else {
// According to Apples Documentation you can determine the corresponding encoding values
}
if ([typeAttribute hasPrefix:@"T@"]) {
NSString * typeClassName = [typeAttribute substringWithRange:NSMakeRange(3,[typeAttribute length]-4)]; //turns @"NSDate" into NSDate
Class typeClass = NSClassFromString(typeClassName);
if (typeClass != nil) {
// Here is the corresponding class even for nil values
}
}
}
free(props);
