iOS runtime (一)

参考连接 https://www.jianshu.com/p/88d11bb12ba1

获取类的属性

• 新建一个 Person 类

@interface Person : NSObject

@property(nonatomic,copy)NSString *name;
@property(nonatomic,assign)NSInteger age;
@property(nonatomic,assign)NSInteger weight;

@end

然后在需要使用runtime的地方导入 #import <objc/runtime.h>

Person *person = [[Person alloc] init];
NSLog(@" %p ",person);
NSLog(@" %p ",[person class]);
NSLog(@" %p ",[person class]);
NSLog(@" %p ",object_getClass(person));
NSLog(@" %p ",object_getClass([Person class]));
NSLog(@" %p ",object_getClass([person class]));

打印:

0x10064d940
0x100002428
0x100002428
0x100002428
0x100002400
0x100002400

• class_copyPropertyList 获取类的属性集合
• property_getName 获取属性的名称
• property_getAttributes 获取属性的真实名字和类型

unsigned int count = 0;
// class_copyPropertyList 获取类的属性集合
objc_property_t *properties = class_copyPropertyList([Person class], &count);
NSLog(@" 属性的个数 - %u ",count);

for (int i = 0; i < count; i++) {
    NSString *name = [NSString stringWithFormat:@"%s",property_getName(properties[i])]; // property_getName 获取属性的名称
    NSString *attribute = [NSString stringWithFormat:@"%s",property_getAttributes(properties[i])]; // property_getAttributes 获取属性的真实名字和类型
    NSLog(@" 属性名字 - %@ ",name);
    NSLog(@" %@ ",attribute);
}

打印结果:

2019-05-30 19:07:19.250977+0800 RunTime[1016:47491]  属性的个数 - 3 
2019-05-30 19:07:19.251527+0800 RunTime[1016:47491]  属性名字 - name 
2019-05-30 19:07:19.251641+0800 RunTime[1016:47491]  T@"NSString",C,N,V_name
2019-05-30 19:07:19.251716+0800 RunTime[1016:47491]  属性名字 - age 
2019-05-30 19:07:19.251769+0800 RunTime[1016:47491]  Tq,N,V_age
2019-05-30 19:07:19.251822+0800 RunTime[1016:47491]  属性名字 - weight 
2019-05-30 19:07:19.251841+0800 RunTime[1016:47491]  Tq,N,V_weight

调用类的一些不公开的方法

• .m 文件中实现如下方法

#import "Person.h"

@implementation Person

// 吃饭的实例方法
-(void)eat
{
    NSLog(@"person eat");
}

// 吃饭的类方法
+(void)eat
{
    NSLog(@"Person Class eat");
}

// 睡觉实例方法
-(void)sleepOfHour:(NSNumber *)hour
{
    NSLog(@"person sleep hour is %@",hour);
}

// 睡觉的实例方法
+(void)sleepOfHour:(NSNumber *)hour
{
    NSLog(@"Person Class sleep hour is %@",hour);
}

// 是否吃饱
-(NSNumber *)eatEnough:(NSNumber *)breadCount
{
    NSLog(@"person eat breadCount is %@",breadCount);
    return breadCount;
}

+(NSNumber *)eatEnough:(NSNumber *)breadCount
{
    NSLog(@"Person Class eat breadCount is %@",breadCount);
    return breadCount;
}

• 导入 #import <objc/runtime.h> 和 #import <objc/message.h>

Person *person = [[Person alloc] init];

((void (*)(id,SEL)) objc_msgSend)(person,NSSelectorFromString(@"eat"));
((void (*)(id,SEL)) objc_msgSend)([Person class],NSSelectorFromString(@"eat"));

((void (*)(id,SEL,NSNumber *)) objc_msgSend)(person,NSSelectorFromString(@"sleepOfHour:"),@2);
((void (*)(id,SEL,NSNumber *)) objc_msgSend)([Person class],NSSelectorFromString(@"sleepOfHour:"),@3);

NSNumber *personBreadCount = ((NSNumber * (*)(id,SEL,NSNumber *)) objc_msgSend)(person,NSSelectorFromString(@"eatEnough:"),@4);
NSLog(@"personBreadCount - %@",personBreadCount);

NSNumber *PersonBreadCount = ((NSNumber * (*)(id,SEL,NSNumber *)) objc_msgSend)([Person class],NSSelectorFromString(@"eatEnough:"),@5);
NSLog(@"PersonBreadCount - %@",PersonBreadCount);

打印:

2019-05-30 19:11:40.644604+0800 RunTime[1035:48715] person eat
2019-05-30 19:11:40.644860+0800 RunTime[1035:48715] Person Class eat
2019-05-30 19:11:40.644950+0800 RunTime[1035:48715] person sleep hour is 2
2019-05-30 19:11:40.645014+0800 RunTime[1035:48715] Person Class sleep hour is 3
2019-05-30 19:11:40.645051+0800 RunTime[1035:48715] person eat breadCount is 4
2019-05-30 19:11:40.645073+0800 RunTime[1035:48715] personBreadCount - 4
2019-05-30 19:11:40.645092+0800 RunTime[1035:48715] Person Class eat breadCount is 5
2019-05-30 19:11:40.645139+0800 RunTime[1035:48715] PersonBreadCount - 5