Method Swizzling is used to extract repeated operations. methodswizzling

Method Swizzling is used to extract repeated operations. methodswizzling
Use Method Swizzling to extract repeated operations

By Wu xueying

Repeated operations, such as data reporting and public features.

1. Create a Category for UIViewController

2. Code:

#import "UIViewController+Analytics.h"#import <objc/runtime.h>@implementation UIViewController (Analytics)+ (void)load {    static dispatch_once_t onceToken;    dispatch_once(&onceToken, ^{        Class class = [self class];        SEL originalSelector = @selector(viewWillAppear:);        SEL swizzledSelector = @selector(ana_viewWillAppear:);        Method originalMethod = class_getInstanceMethod(class, originalSelector);        Method swizzledMethod = class_getInstanceMethod(class, swizzledSelector);        BOOL success = class_addMethod(class, originalSelector, method_getImplementation(swizzledMethod), method_getTypeEncoding(swizzledMethod));        if (success) {            class_replaceMethod(class, swizzledSelector, method_getImplementation(originalMethod), method_getTypeEncoding(originalMethod));        } else {            method_exchangeImplementations(originalMethod, swizzledMethod);        }    });}- (void)ana_viewWillAppear:(BOOL)animated {    [self ana_viewWillAppear:animated];    NSLog(@"ana_viewWillAppear");    NSLog(@"%@",self);    MTA_Report();    [self hideNavigationShadowLine];}@end

3. Output
09:17:59. 838 Test [37292: 2748514] ana_viewWillAppear
09:17:59. 838 Test [37292: 2748514] ViewController: 0x7fb7515291c0>