将图像添加到子类的UIImageView

Question

I am trying to add a tap gesture from a subclassed UIImageView and then control the tap from the View Controller. I am not getting any compiling errors but "addSubview" is not displaying any image. How can make the UIImageView to be displayed?

If I try to control the tap and pan gestures from the subclassed UIImageVIew I have no problems but I would like to control these functions from the View Controller

Relevant code looks like this.

UIImageView subclass

- (id)initWithCoder:(NSCoder *)aDecoder
{
    self = [super initWithCoder:aDecoder];
    if (self)
   {
    //self.userInteractionEnabled = YES;
    previewController = [[PreviewController alloc]init];
    [previewController self];
    [self addSubview:character];
    // Tap Initialization code
    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:(PreviewController *)self.previewController action:@selector(addCharacter:)];
    [self addGestureRecognizer:tap];
    self.userInteractionEnabled = YES;

   }
    return self;
}

View Controller

- (void)addCharacter:(UITapGestureRecognizer *)t
{
    NSLog(@"add character");
    imageNSArray = [NSMutableArray array];
    uiImg = [UIImage imageNamed:@"homer.png"];
    CGPoint loc = [t locationInView:self.view];
    character = [[UIImageView alloc] initWithImage:uiImg];
    character.center = loc;
    [imageNSArray addObject:character];
    //Locate the imageNSArray on frameImageView area only.
    [self.view addSubview:character];     
    UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self    action:@selector(panCharacter:)];
    [self.character addGestureRecognizer:pan];
    character.userInteractionEnabled = YES;
}

Answer 1

put a view behind your subclassed imageView. Apply the gestureRecognition to the new View. You can control your tap gesture from new view. Let me know if i am not clear, or if more info needed.

Answer 2

I think what you want is.. .you want to show a image when user taps on screen. Do following steps: 1. drag & drop a tap gesture recognizer on default view of your view controller. 2. connect (ctrl +) gestureRecognizer with ViewController.m

Take a look at this code. (Just modified your code)

- (IBAction)onTap:(UITapGestureRecognizer *)sender {
    NSLog(@"add character");

    UIImage * uiImg = [UIImage imageNamed:@"sel.png"];
    CGPoint loc = [sender locationInView:self.view];
    UIImageView * character = [[UIImageView alloc] initWithImage:uiImg];
    character.center = loc;


    [self.view addSubview:character];
}

Let me know if this is not what you want…

Edit better go for this code… No need to do above steps.

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.

    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(onTap:)];
    [self.view addGestureRecognizer:tap];
    self.view.userInteractionEnabled = YES;
}

- (void)onTap:(UITapGestureRecognizer *)sender
{
    NSLog(@"add character");

    UIImage * uiImg = [UIImage imageNamed:@"sel.png"];
    CGPoint loc = [sender locationInView:self.view];
    UIImageView * character = [[UIImageView alloc] initWithImage:uiImg];
    character.center = loc;

    [self.view addSubview:character];
}