• 重載類的“+(void)load”方法释簿，在程序加載到內(nèi)存時利用Runtime的

method_exchangeImplementations

等接口將方法的實現(xiàn)互相交換匹涮。當(dāng)方法被調(diào)用時就會被勾住(Hook)孵户，執(zhí)行我們的方法宵距。

@interface HookUtility : NSObject

+ (void)swizzlingInClass:(Class)cls originalSelector:(SEL)originalSelector swizzledSelector:(SEL)swizzledSelector;

@end

@implementation HookUtility

+ (void)swizzlingInClass:(Class)cls originalSelector:(SEL)originalSelector swizzledSelector:(SEL)swizzledSelector {
    Class class = cls;
    Method originalMethod = class_getInstanceMethod(class, originalSelector);
    Method swizzledMethod = class_getInstanceMethod(class, swizzledSelector);
    BOOL didAddMethod = class_addMethod(class, originalSelector, method_getImplementation(swizzledMethod), method_getTypeEncoding(swizzledMethod));
    if (didAddMethod) {
        class_replaceMethod(class, swizzledSelector, method_getImplementation(originalMethod), method_getTypeEncoding(originalMethod));
        
    } else {
        method_exchangeImplementations(originalMethod, swizzledMethod);
    }
}

@end

• 頁面進(jìn)入的埋點統(tǒng)計，交換ViewController的DidAppear方法的實現(xiàn)以ViewController的類名為識別符進(jìn)行埋點統(tǒng)計略荡。

@implementation UIViewController (userStastistics)

+ (void)load {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        SEL originalSelector = @selector(viewWillAppear:);
        SEL swizzledSelector = @selector(swiz_viewWillAppear:);
        [HookUtility swizzlingInClass:[self class] originalSelector:originalSelector swizzledSelector:swizzledSelector];
    });
}

- (void)swiz_viewWillAppear:(BOOL)animated {
    // 埋點上報
    NSString *targetName = NSStringFromClass([self class]);
    NSLog(@"上報到數(shù)據(jù)統(tǒng)計中心的targetName=%@", targetName);
    // 執(zhí)行被交換的實現(xiàn)
    [self swiz_viewWillAppear:animated];
}

@end

• 控件交互事件(點擊庵佣、拖動、雙擊...)的埋點統(tǒng)計汛兜，交換

sendAction:to:forEvent:

方法實現(xiàn)巴粪，以按鈕的“類名+target名+action名”作為識別符上報數(shù)據(jù)統(tǒng)計中心

@implementation UIControl (userStastistics)

+ (void)load {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        SEL originalSelector = @selector(sendAction:to:forEvent:);
        SEL swizzledSelector = @selector(swiz_sendAction:to:forEvent:);
        [HookUtility swizzlingInClass:[self class] originalSelector:originalSelector swizzledSelector:swizzledSelector];
    });
}

- (void)swiz_sendAction:(SEL)action to:(id)target forEvent:(UIEvent *)event {
    //插入埋點代碼
    [self performUserStastisticsAction:action to:target forEvent:event];
    // 執(zhí)行被交換的實現(xiàn)
    [self swiz_sendAction:action to:target forEvent:event];
}

- (void)performUserStastisticsAction:(SEL)action to:(id)target forEvent:(UIEvent *)event; {
    
    NSString *className = NSStringFromClass([self class]);
    NSString *targetName = NSStringFromClass([target class]);
    NSString *actionString = NSStringFromSelector(action);
    
    NSLog(@"上報到數(shù)據(jù)統(tǒng)計中心=%@_%@_%@", className, targetName, actionString);
}

@end

• 擴展-頁面停留時長統(tǒng)計：可通過以上ViewController的擴展類去擴展屬性，在DidAppear方法里給該屬性賦值粥谬，在DidDisappear方法里計算時間差并且交換方法實現(xiàn)達(dá)到頁面停留時長埋點需求
• 擴展-批量上報/實時上報：通過本地plist配置文件去自定義一些特殊行為肛根。