I set the event to a view containing UIImageView, but it doesn't handle it in the UIImageView part.

Change the UILabel instance and UIImageView instance property userInteractionEnabled to Enabled (YES).You can do this either on a program or on a storyboard.
userInteractionEnabled is a property of UIView, and the default is YES.In other words, responding to user interaction is the default.However, only UILabel and UIImageView have a default of NO.This is probably because most of them use UIImageView and UILabel to display "just" images and text that they don't want to respond to user interaction.

Oh, it was a little late... I'm not going to answer the question because I'm half done like this, but I'm going to put the relevant tips on it and put a little more shape on it.

Tap UILabel, UIImageView, which is not a subclass of UIControl, to show how to run the action method.This eliminates the need to place UIControl subclasses behind it.

We use the UIGestureRecognizer for that.In this subclass UITapGestureRecognizer, create a UIImageView instance that responds to the tap

#import "ViewController.h"

@ interface ViewController()

// Image View Responding to Tap
@property(weak, nonatomic) IBOutlet UIImageView* imageView;

@end

@implementation ViewController

- (void) viewDidLoad{
    superviewDidLoad;

    // Create a UItapGestureRecognizer instance and incorporate it into the Image view. 
    UITapGestureRecognizer*tapGestureRecognizer=[[UITapGestureRecognizer alloc] initWithTarget:selfaction:@selector(imageTap:)];
    self.imageView addGestureRecognizer:tapGestureRecognizer;
}

// Action method called when you tap Image View.
- (void) imageTap: (UITapGestureRecognizer*)recognizer{
    NSLog(@"Image View was pasted.");
}

@end

You can do the same with UILabel.