埋點可以解決兩大類問題: 一是了解用戶使用App的行為, 二是降低分析線上問題的難度

常見的埋點方式: 代碼埋點、可視化埋點、無埋點

代碼埋點: 通過手寫代碼, 精確的在需要埋點的代碼處加上埋點的代碼, 存在開發(fā)工作量大, 后期難以維護的問題
可視化埋點: 增加修改的工作可視化了, 提升體驗
無埋點: 埋點代碼不會出現(xiàn)在業(yè)務代碼中, 容易管理和維護, 缺點在于, 埋點成本高, 后期解析復雜, 優(yōu)點是節(jié)省大量的開發(fā)和維護成本

運行時方法替換方式進行埋點

常見三種埋點: 頁面進入次數(shù)、頁面停留時間、點擊事件
利用運行時method_exchangeImplementations接口將方法的實現(xiàn)進行了交換, 原方法調用時就會被hook住, 從而去執(zhí)行指定的方法

 #import "SMHook.h"
 #import <objc/runtime.h>

 @implementation SMHook
 + (void)hookClass:(Class)classObject fromSelector:(SEL)fromSelector toSelector:(SEL)toSe
 Class class = classObject;
 // 得到被替換類的實例方法
 Method fromMethod = class_getInstanceMethod(class, fromSelector);
 // 得到替換類的實例方法
 Method toMethod = class_getInstanceMethod(class, toSelector);
 // class_addMethod 返回成功表示被替換的方法沒實現(xiàn)，然后會通過 class_addMethod 方法先實現(xiàn)
 if(class_addMethod(class, fromSelector, method_getImplementation(toMethod), method_g
 // 進行方法的替換
 class_replaceMethod(class, toSelector, method_getImplementation(fromMethod), met
 } else {
 // 交換 IMP 指針
 method_exchangeImplementations(fromMethod, toMethod);
 }
 }
 @end

頁面進入次數(shù)、頁面停留時間都需要對UIViewController生命周期進行埋點, 可以創(chuàng)建一個UIViewController的Catagory

@implementation UIViewController (logger)
+ (void)load {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        // 通過 @selector 獲得被替換和替換方法的 SEL，作為 SMHook:hookClass:fromeSelector:toSelector 的參數(shù)傳入 
        SEL fromSelectorAppear = @selector(viewWillAppear:);
        SEL toSelectorAppear = @selector(hook_viewWillAppear:);
        [SMHook hookClass:self fromSelector:fromSelectorAppear toSelector:toSelectorAppear];
        
        SEL fromSelectorDisappear = @selector(viewWillDisappear:);
        SEL toSelectorDisappear = @selector(hook_viewWillDisappear:);
        
        [SMHook hookClass:self fromSelector:fromSelectorDisappear toSelector:toSelectorDisappear];
    });
}

- (void)hook_viewWillAppear:(BOOL)animated {
    // 先執(zhí)行插入代碼，再執(zhí)行原 viewWillAppear 方法
    [self insertToViewWillAppear];
    [self hook_viewWillAppear:animated];
}
- (void)hook_viewWillDisappear:(BOOL)animated {
    // 執(zhí)行插入代碼，再執(zhí)行原 viewWillDisappear 方法
    [self insertToViewWillDisappear];
    [self hook_viewWillDisappear:animated];
}

- (void)insertToViewWillAppear {
    // 在 ViewWillAppear 時進行日志的埋點
    [[[[SMLogger create]
       message:[NSString stringWithFormat:@"%@ Appear",NSStringFromClass([self class])]]
      classify:ProjectClassifyOperation]
     save];
}
- (void)insertToViewWillDisappear {
    // 在 ViewWillDisappear 時進行日志的埋點
    [[[[SMLogger create]
       message:[NSString stringWithFormat:@"%@ Disappear",NSStringFromClass([self class])]]
      classify:ProjectClassifyOperation]
     save];
}
@end

對于點擊事件, 可以通過運行時方法替換的方式進行無侵入埋點, 找到點擊事件的方法sendAction:to:forEvent:, 然后在+load()方法使用SMHook替換
UIButton在一個視圖類中可能有多個不同的繼承類, 相同UIButton的子類在不同視圖類的埋點也要區(qū)別開, 需要通過“action選擇器名 NSStringFromSelector(action)”+“視圖類名NSStringFromClass([target class])”組合成一個唯一的標識, 進行埋點

+ (void)load {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        // 通過 @selector 獲得被替換和替換方法的 SEL，作為 SMHook:hookClass:fromeSelector:toSelector 的參數(shù)傳入
        SEL fromSelector = @selector(sendAction:to:forEvent:);
        SEL toSelector = @selector(hook_sendAction:to:forEvent:);
        [SMHook hookClass:self fromSelector:fromSelector toSelector:toSelector];
    });
}

- (void)hook_sendAction:(SEL)action to:(id)target forEvent:(UIEvent *)event {
    [self insertToSendAction:action to:target forEvent:event];
    [self hook_sendAction:action to:target forEvent:event];
}
- (void)insertToSendAction:(SEL)action to:(id)target forEvent:(UIEvent *)event {
    // 日志記錄
    if ([[[event allTouches] anyObject] phase] == UITouchPhaseEnded) {
        NSString *actionString = NSStringFromSelector(action);
        NSString *targetName = NSStringFromClass([target class]);
        [[[SMLogger create] message:[NSString stringWithFormat:@"%@ %@",targetName,actionString]] save];
    }
}