从自定义 UIControl 子类转发事件

Question

我的自定义子类扩展 UIControl (EditableImageView) 基本上它包含 3 个子视图：

• UIButton (UIButtonTypeCustom)
• UIImageView
• UILabel

所有类都工作得很好，但现在我想将从此类生成的一些事件连接到另一个类。特别是当按下按钮时，我想将事件转发给所有者视图控制器，以便我可以处理该事件。问题是我不知道如何实现这种行为。 在 EditableImageView 中，我可以使用 [button addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside] 捕获触摸事件，但我不知道如何在 buttonPressed 选择器内部转发它。 我也尝试实现touchesBegan，但它似乎从未被调用过...

我想以这种方式从视图控制器捕获按钮按下事件：

- (void)viewDidLoad {
[super viewDidLoad];

self.imageButton = [[EditableImageView alloc] initWithFrame:CGRectMake(50.0f, 50.0f, 80.0f, 80.0f)];
[imageButton addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
[self.view addSubview:imageButton];
[imageButton setEditing:NO];

}

这是我的UIControl 子类初始化方法：

- (id)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        [self setBackgroundColor:[UIColor clearColor]];

        button = [UIButton buttonWithType:UIButtonTypeCustom];
        button.frame = CGRectMake(0.0f, 0.0f, frame.size.width, frame.size.height);
        [button setImage:[UIImage imageNamed:@"nene_70x70.png"] forState:UIControlStateNormal];
        [button addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];

        [self addSubview:button];

        transparentLabelBackground = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"editLabelBackground.png"]];
        transparentLabelBackground.hidden = YES;
        [self addSubview:transparentLabelBackground];

        // create edit status label
        editLabel = [[UILabel alloc] initWithFrame:CGRectZero];
        editLabel.hidden = YES;
        editLabel.userInteractionEnabled = NO;  // without this assignment the button will not be clickable
        editLabel.textColor = [UIColor whiteColor];
        editLabel.backgroundColor = [UIColor clearColor];
        editLabel.textAlignment = UITextAlignmentLeft;
        UIFont *labelFont = [UIFont systemFontOfSize:16.0];
        editLabel.font = labelFont;     
        editLabel.text = @"edit"; 
        labelSize = [@"edit" sizeWithFont:labelFont];

        [self addSubview:editLabel];
    }

    return self;
}

谢谢。

Answer 1

我用这种方式解决了：

EditableImageView.h:

@interface EditableImageView : UIControl {
UIButton *button;
UIImageView *transparentLabelBackground;
UILabel *editLabel;
CGSize labelSize;

BOOL editing;
}

@property (nonatomic, retain) UIButton *button;
@property (nonatomic, retain) UILabel *editLabel;
@property (nonatomic, retain) UIImageView *transparentLabelBackground;
@property (nonatomic, getter=isEditing) BOOL editing;

- (void)buttonPressed:(id)sender;
@end

EditableImageView.m:

 (id)initWithFrame:(CGRect)frame {
    if (self = [super initWithFrame:frame]) {
        [self setBackgroundColor:[UIColor clearColor]];

        button = [UIButton buttonWithType:UIButtonTypeCustom];
        button.frame = CGRectMake(0.0f, 0.0f, frame.size.width, frame.size.height);
        [button setImage:[UIImage imageNamed:@"nene_70x70.png"] forState:UIControlStateNormal];
        [button addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
        .......
    }
}


- (void)buttonPressed:(id)sender {
[self sendActionsForControlEvents:UIControlEventTouchUpInside];
}

MyController.m:

- (void)viewDidLoad {
    [super viewDidLoad];
    self.imageButton = [[EditableImageView alloc] initWithFrame:CGRectMake(50.0f, 50.0f, 80.0f, 80.0f)];
    [imageButton addTarget:self action:@selector(buttonPressed:) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:imageButton];
}

- (void)buttonPressed:(id)sender {
    NSLog(@"buttonPressed!");
}