方法替换

#import "NSURL+url.h"

#import <objc/message.h>

@implementation NSURL (url)

//方法互换

+(void)load

{

    

Method zl_url =  class_getClassMethod([NSURLclass], @selector(ZL_urlwithstr:));

Method  url = class_getClassMethod([NSURLclass], @selector(URLWithString:));

    method_exchangeImplementations(zl_url, url);

}

//方法的互换方法注意

+(instancetype)ZL_urlwithstr:(NSString *)str

{

    NSURL *url = [NSURLZL_urlwithstr:str];

    if (!url) {

        NSLog(@"唯恐");

    }

    return url;

}

@end