美文网首页
iOS - Runtime之消息处理

iOS - Runtime之消息处理

作者: AKyS佐毅 | 来源:发表于2019-02-15 12:37 被阅读14次

    年后归来，温故知新。

    1、类方法和实例方法之间的区别

    /*
 *1.实例方法和类方法的调用
 */
CFPerson *person = [[CFPerson alloc]init];
[person eating];        //实例方法调用
[CFPerson sleeping];    //类方法调用

((void (*)(id,SEL))(void *)objc_msgSend)((id)person,sel_registerName("eating"));
((void (*)(id,SEL))(void *)objc_msgSend)(objc_getClass("CFPerson"),sel_registerName("sleeping"));

//        [person performSelector:@selector(sleeping)];
//        [CFPerson performSelector:@selector(eating)];

/*
 *实例->类->元类
 获取isa，在isa对象的方法列表中查找指定方法
 传入实例对象，在类的方法列表中查找
 传入类对象，在元类的方法列表中查找
 */

/*
 *2.验证
 class_getMethodImplementation
 从指定的类方法列表中查找指定的方法，返回此方法的地址
 */
IMP eatIMP = class_getMethodImplementation([CFPerson class], @selector(eating));
eatIMP();
Class metaCls = objc_getMetaClass(class_getName([CFPerson class]));
IMP sleepIMP = class_getMethodImplementation(metaCls, @selector(sleeping));
sleepIMP();

    2、objc_msgSend介绍

    int main(int argc, const char * argv[]) {
    @autoreleasepool {
        /*
         *1.正常调用方法
         */
        CFPerson *person  =  [CFPerson new];
        CFStudent *student  = [CFStudent new];
        [person eatingWithFood:@"apple" inPlace:@"kitchen"];
        [person playing];
        [CFPerson sleeping];
        
        /*
         *2.使用objc_msgSend
         */
        SEL eatSel = @selector(eatingWithFood:inPlace:);
        SEL playSel = @selector(playing);
        SEL sleepSel = NSSelectorFromString(@"sleeping");
        objc_msgSend(person,playSel);
        objc_msgSend(person,eatSel,@"apple",@"kitchen");
        objc_msgSend([CFPerson class],sleepSel);
        
        /*
         objc_msgSend_stret：消息返回的是结构体
         objc_msgSend_fpret：消息返回的是浮点数
         objc_msgSendSuper：给父类发消息
         */
        struct objc_super objSuper;
        objSuper.receiver = student;
        objSuper.super_class = [CFPerson class];
        objc_msgSendSuper(&objSuper,playSel);
    }
    return 0;
}

    3、消息发送流程

    int main(int argc, const char * argv[]) {
    @autoreleasepool {
        CFPerson *person = [[CFPerson alloc]init];
        SEL eatSel = @selector(eatingWithFood:inPlace:);
        IMP eatIMP = [person methodForSelector:eatSel];
        
        
        /*
         消息发送流程部分是通过汇编实现的，所以实际上差距也不大
         */
        NSDate *begin = [NSDate date];
        for (int i =0; i<100000000; i++) {
            eatIMP(person,eatSel,@"apple",@"kitchen");
        }
        NSDate *end = [NSDate date];
        NSLog(@"跳过消息发送流程，时间花费为：%.5f",[end timeIntervalSinceDate:begin]);
        
        begin = [NSDate date];
        for (int i =0; i<100000000; i++) {
            [person eatingWithFood:@"apple" inPlace:@"kitchen"];
        }
        end = [NSDate date];
        NSLog(@"正常消息发送流程，时间花费为：%.5f",[end timeIntervalSinceDate:begin]);
    }
    return 0;
}

    执行结果：

    直接跳过消息发送流程[1658:85755] 跳过消息发送流程，时间花费为：2.82438
直接跳过消息发送流程[1658:85755] 正常消息发送流程，时间花费为：3.01274
    image image

    4、直接跳过消息发送流程

    int main(int argc, const char * argv[]) {
    @autoreleasepool {
        CFPerson *person = [[CFPerson alloc]init];
        SEL eatSel = @selector(eatingWithFood:inPlace:);
        IMP eatIMP = [person methodForSelector:eatSel];
        
        /*
         消息发送流程部分是通过汇编实现的，所以实际上差距也不大
         */
        NSDate *begin = [NSDate date];
        for (int i =0; i<100000000; i++) {
            eatIMP(person,eatSel,@"apple",@"kitchen");
        }
        NSDate *end = [NSDate date];
        NSLog(@"跳过消息发送流程，时间花费为：%.5f",[end timeIntervalSinceDate:begin]);
        
        begin = [NSDate date];
        for (int i =0; i<100000000; i++) {
            [person eatingWithFood:@"apple" inPlace:@"kitchen"];
        }
        end = [NSDate date];
        NSLog(@"正常消息发送流程，时间花费为：%.5f",[end timeIntervalSinceDate:begin]);
    }
    return 0;
}
    image

    5、消息转发流程

    image 
    @implementation RuntimeObject

void testIMP (void){
    NSLog(@"testIMP invoke");
}

+ (BOOL)resolveInstanceMethod:(SEL)sel
{
    if (sel == @selector(test)) {
        
        NSLog(@"resolveInstanceMethod:");
        return NO;
    }
    return [super resolveInstanceMethod:sel];
}

- (id)forwardingTargetForSelector:(SEL)aSelector{
    if (aSelector == @selector(test)) {
        NSLog(@"forwardingTargetForSelector:");
        return nil;
    }
    
    return [super forwardingTargetForSelector:aSelector];
}

- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector{
    
    if (aSelector == @selector(test)) {
        NSLog(@"methodSignatureForSelector:");
        return [NSMethodSignature signatureWithObjCTypes:"v@:"];
    }
    
    return [super methodSignatureForSelector:aSelector];
}

- (void)forwardInvocation:(NSInvocation *)anInvocation
{
    NSLog(@"forwardInvocation:");
}

@end

    @interface CFPerson : NSObject
- (void)eating;
@end

@implementation CFPerson
- (void)eating
{
    NSLog(@"Person eating!");
}
@end
-------------------------------------------------------------------
@interface CFStudent : NSObject

@end

@implementation CFStudent
- (id)forwardingTargetForSelector:(SEL)aSelector {
    if (aSelector == @selector(eating)) {
        return [CFPerson new];
    }
    return [super forwardingTargetForSelector:aSelector];
}
@end

-------------------------------------------------------------------
int main(int argc, const char * argv[]) {
    @autoreleasepool {
        /*
         打印runtime信息
         开启：call (void)instrumentObjcMessageSends(YES)
         关闭：call (void)instrumentObjcMessageSends(NO)
         /private/tmp/ 文件夹，找到最新的 msgSends-xxxx文件
         */
        CFStudent *student  = [CFStudent new];
        [student performSelector:@selector(eating)];
        [student performSelector:@selector(eating)];
    }
    return 0;
}

    6、类方法和实例方法的动态消息解析

    @interface CFPerson : NSObject
//姓名
@property(nonatomic,copy)NSString *name;
//年龄
@property(nonatomic,copy)NSString *age;
@end
  
-------------------------------------------------------------------

NSString *_name;
@implementation CFPerson
@dynamic name;
@synthesize age;

void playIMP(id cls,SEL cmd){
    NSLog(@"Person playing!");
}

void eatIMP(id cls,SEL cmd){
    NSLog(@"Person eating!");
}

- (void)sleeping
{
    NSLog(@"Person sleeping！");
}

 + (BOOL)resolveClassMethod:(SEL)sel
{
    //动态添加类方法
    /*
     *v：返回void @：表示对象 ：表示_cmd
     */
    if (sel == NSSelectorFromString(@"playing")) {
//        class_addMethod(object_getClass([CFPerson class]), sel, (IMP)playIMP, "v@:");
        class_addMethod(objc_getMetaClass("CFPerson"), sel, (IMP)playIMP, "v@:");
        return YES;
    }
    //methodForSelector
    if(sel == @selector(sleeping)){
        class_addMethod(objc_getMetaClass("CFPerson"), sel, [[CFPerson new] methodForSelector:@selector(sleeping)], "v@:");
        return YES;
    }
    return  [super resolveClassMethod:sel];
}

+ (BOOL)resolveInstanceMethod:(SEL)sel
{
    if (sel == NSSelectorFromString(@"eating")) {
        class_addMethod([CFPerson class], sel, (IMP)eatIMP, "v@:");
        return YES;
    }
    if (sel == @selector(setName:)) {
        class_addMethod(self, sel, (IMP)setName, "v@:@");
        return YES;
    }
    if (sel == @selector(name)) {
        class_addMethod(self, sel, (IMP)getName, "@@:");
        return YES;
    }
    return  [super resolveInstanceMethod:sel];
}

void setName(id cls,SEL cmd, NSString *name)
{
    _name = name;
}

id getName(id cls,SEL cmd)
{
    return _name;
}
@end

-------------------------------------------------------------------

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        //1.类方法
        [CFPerson performSelector:NSSelectorFromString(@"playing")];
        [CFPerson performSelector:NSSelectorFromString(@"sleeping")];
        //2.实例方法
        CFPerson *person = [[CFPerson alloc]init];
        [person performSelector:NSSelectorFromString(@"eating")];
        [person performSelector:NSSelectorFromString(@"sleeping")];     //可以执行成功
        
        /*
         *3.@dynamic
         */
        person.name = @"lilei";
        NSLog(@"person.name：%@",person.name);
        
        person.age = @"20";
        NSLog(@"person.age：%@",person.age);
    }
    return 0;
}

    7、重定向

    @interface CFPerson : NSObject

@end

-------------------------------------------------------------------
  
@implementation CFPerson
- (id)forwardingTargetForSelector:(SEL)aSelector
{
    if (aSelector == NSSelectorFromString(@"studying")) {
        return [CFStudent new] ;
    }
    return [super forwardingTargetForSelector:aSelector];
}
@end

-------------------------------------------------------------------

@interface CFStudent : NSObject
//学习
- (void)studying;
@end
  
-------------------------------------------------------------------
  
@implementation CFStudent
//学习
- (void)studying
{
    NSLog(@"Student studying！");
}
@end
-------------------------------------------------------------------

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        CFPerson *person = [[CFPerson alloc]init];
        [person performSelector:NSSelectorFromString(@"studying")];
    }
    return 0;
}

    8、转发

    image 
    @interface CFPerson : NSObject
//吃东西
- (void)eating;
@end

-------------------------------------------------------------------

@implementation CFPerson
//吃东西
- (void)eating;
{
    NSLog(@"Person eating！");
}

//生成对应的方法签名
- (NSMethodSignature *)methodSignatureForSelector:(SEL)aSelector
{
    if (aSelector == NSSelectorFromString(@"playing")) {
//        return [self methodSignatureForSelector:@selector(eating)];
        return [NSMethodSignature signatureWithObjCTypes:"v@:"];
    }
    if (aSelector == NSSelectorFromString(@"studying")) {
        return [[CFStudent new] methodSignatureForSelector:@selector(studying)];
    }
    return [super methodSignatureForSelector:aSelector];
}

- (void)forwardInvocation:(NSInvocation *)anInvocation
{
    if (anInvocation.selector == NSSelectorFromString(@"playing")) {
        //1.改变执行的函数
        anInvocation.selector = @selector(eating);
        [anInvocation invokeWithTarget:self];
    }
    if (anInvocation.selector == NSSelectorFromString(@"studying")) {
        //2.改变执行的目标
        [anInvocation invokeWithTarget:[CFStudent new]];
    }
    //3.同时改变执行函数和执行目标....
}

@end

-------------------------------------------------------------------

@interface CFStudent : NSObject
//学习
- (void)studying;
@end

-------------------------------------------------------------------

@implementation CFStudent
//学习
- (void)studying
{
    NSLog(@"Student studying！");
}
@end
  
-------------------------------------------------------------------

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        CFPerson *person = [[CFPerson alloc]init];
        //把执行playing方法，变成执行person里的eating
        [person performSelector:NSSelectorFromString(@"playing")];
        //把执行studying方法，交给student类
        [person performSelector:NSSelectorFromString(@"studying")];
    }
    return 0;
}

    相关文章

      网友评论

          本文标题：iOS - Runtime之消息处理

          本文链接：https://www.haomeiwen.com/subject/soupeqtx.html

          延伸阅读

          深度阅读

          • 您也可以注册成为美文阅读网的作者，发表您的原创作品、分享您的心情！

          栏目导航

          热点阅读

          关于我们|服务条款|联系我们|iOS - Runtime之消息处理|投稿指南|网站地图|RSS订阅|排版工具|手机版

          提供经典美文摘抄,优美散文欣赏,现代诗歌精选,短篇小说,心情随笔,表白情书范文,故事会在线阅读欣赏

          Copyright © 2014-2023 Haomeiwen.com All Rights Reserved. 好美文阅读网 版权所有

          备案信息：桂公网安备 45052102000051号 · 桂ICP备13007215号-3

          本站所收录作品、热点评论等信息部分来源互联网，目的只是为了系统归纳学习和传递资讯

          所有作品版权归原创作者所有，与本站立场无关，如不慎侵犯了你的权益，请联系我们告知，我们将做删除处理！