how to set UIButton type in UIButton Subclass

问题

I am subclassing the UIButton, what i want is to set the button type to Round Rect.

Button.h

@interface Button : UIButton {}
    - (void)initialize;
@end

Button.m

@implementation Button

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        [self initialize];
    }
    return self;
}


-(id)initWithCoder:(NSCoder *)aDecoder {
    self = [super initWithCoder:aDecoder];
    if(self){
        [self initialize];
    }
    return self;
}

- (void)initialize
{
    self.titleLabel.font = [UIFont systemFontOfSize:20];
    self.titleLabel.textColor = [UIColor redColor];
    self.titleLabel.textAlignment = UITextAlignmentCenter;
   //[UIButton buttonWithType:UIButtonTypeRoundedRect];
}

@end

Here i tried [UIButton buttonWithType:UIButtonTypeRoundedRect] but it doesn't work. Can anyone suggest how to make it work?

I know in many previous post it has been said that Subclassing UIButton is not recommended, but the fact that in Developer's Docs there is no mention about NOT subclassing it.

回答1:

You may find the discussion at CocoaBuilder's thread How to subclass UIButton? helpful, particularly Jack Nutting's suggestion to ignore the buttonType:

Note that this way the buttonType isn't explicitly set to anything, which probably means that it's UIButtonTypeCustom. The Docs don't seem to actually specify that, but since that's the 0 value in the enum, that's likely what happens (and that seems to be the observable behavior as well)

回答2:

not quite what you're looking for, but remember that your subclass still has the buttonWithType method, and it works fine.

buttonWithType calls your subclasses initWithFrame, and sets the type appropriately.

SubclassButton *myButton=[SubclassButton buttonWithType:UIButtonTypeRoundedRect];

回答3:

UIButton subclass in Swift

*The following code works in Swift 3 and above.

You cannot set the buttonType of a UIButton subclass by design. It is automatically set to custom which means you get a plain appearance and behavior as a starting point.

If you want to reuse code that sets the button's appearance, you can do this without subclassing. One approach is by providing factory methods that create a UIButton and set visual properties.

Example factory method to avoid subclassing

extension UIButton {
    static func createStandardButton() -> UIButton {
        let button = UIButton(type: UIButtonType.system)
        button.titleLabel?.font = UIFont.boldSystemFont(ofSize: 16)
        button.setTitleColor(UIColor.black, for: .normal)
        button.setTitleColor(UIColor.gray, for: .highlighted)
        return button
    }
}

let button = UIButton.createStandardButton()

I avoid subclassing UIButton when other customization techniques suffice. The factory method example is one option. There are other options including the UIAppearance API, etc.

Sometimes there are customization needs that require subclassing. For example, I've created UIButton subclasses to take fine control over how the button animates in response to touch events or to have the button call a predefined delegate or closure when tapped (as opposed to assigning a #selector to each instance).

The following is a basic UIButton subclass example as a starting point.

Example UIButton Subclass

internal class CustomButton: UIButton {

    init() {
        // The frame can be set outside of the initializer. Default to zero.
        super.init(frame: CGRect.zero)
        initialize()
    }

    required init?(coder aDecoder: NSCoder) {
        // Called when instantiating from storyboard or nib
        super.init(coder: aDecoder)
        initialize()
    }

    func initialize() {
        print("Execute common initialization code")
    }
}

let button = CustomButton()
print(button.buttonType == .custom)  // true

 

A note about UIButtonType

Since the question was asked in 2012, UIButtonType.roundedRect has been deprecated. The header file comments say to use UIButtonType.system instead.

The following is from UIButton.h converted to Swift in Xcode

public enum UIButtonType : Int {

    case custom // no button type

    @available(iOS 7.0, *)
    case system // standard system button

    case detailDisclosure
    case infoLight
    case infoDark
    case contactAdd

    public static var roundedRect: UIButtonType { get } // Deprecated, use UIButtonTypeSystem instead
}

回答4:

With iOS7, this is more relevant than before, as sometimes you need to use UIButtonTypeSystem, and you can't simply override init and do [MyButton alloc] init], because then it's a UIButtonTypeCustom, which doesn't reflect tintColor nor have nice highlight fade effects.

To subclass, make a static constructor like so:

+ (instancetype)myButtonWithTitle:(NSString *)title imageNamed:(NSString *)imageName target:(id)target action:(SEL)action {
    MyButton *button = [self buttonWithType:UIButtonTypeSystem];
    ... my custom setup for title, image, target, etc ...
    return button;
}

回答5:

You can definitely subclass UIButton. I have successfully created a DateButton which looks like a UITextField but when the user touches it it displays a DatePicker in a Popover. Has a property for storing the Date, etc. Let me know if the above never solved your problem and I'll post details more.

回答6:

What about this?

- (id)initWithFrame:(CGRect)frame 
{
    self = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 
    if (self) {
        self.frame = frame;
    }

    return self;
}

来源：https://stackoverflow.com/questions/10277863/how-to-set-uibutton-type-in-uibutton-subclass