我以编程方式创建了一个UIView并添加了一个UIButton作为它的子视图.
我希望UIViewController成为该按钮操作的目标.
我该怎么办?
如果它是由Interface Builder创建的,那么使用IBAction很容易.
我希望UIViewController成为该按钮操作的目标.
我该怎么办?
如果它是由Interface Builder创建的,那么使用IBAction很容易.
解决方法
如果您以编程方式将按钮添加到UIView的子类,那么您可以通过以下两种方式之一执行此操作:
>您可以使按钮成为视图的属性,然后在实例化视图的viewController中,您可以按如下方式设置按钮的目标:
[viewSubclass.buttonName addTarget:self action:@selector(buttonTapped:) forControlEvents:UIControlEventTouchUpInside];
这会将按钮的目标设置为viewController.m中buttonTapped的方法
>您可以在子视图中创建协议,父视图控件将遵循该协议.在您的视图中,当您添加按钮时,将其设置为在视图中调用方法.然后从该视图中调用委托方法,以便viewController可以响应它:
在顶部您的视图子类.h创建协议:
@protocol ButtonProtocolName - (void)buttonWasPressed; @end
为委托创建属性:
@property (nonatomic,assign) id <ButtonProtocolName> delegate;
在子类.m中设置按钮选择器:
[button addTarget:self action:@selector(buttonTapped:) forControlEvents:UIControlEventTouchUpInside];
- (void)buttonTapped:(id)sender { [self.delegate buttonWasPressed]; }
在viewController.h中,您需要确保它符合协议:
@interface someViewController : UIViewController <SomeButtonProtocolName>
在初始化子视图时,在viewController.m中,您必须设置委托:
SomeView *view = ... // Init your view // Set the delegate view.delegate = self;
最后,将delegate方法buttonWasPressed添加到viewController.m:
- (void)buttonWasPressed { // Put code here for button's intended action. }
更新以提供Swift示例
// Simple delegate protocol. protocol SomeViewDelegate: class { // Method used to tell the delegate that the button was pressed in the subview. // You can add parameters here as you like. func buttonWasPressed() } class SomeView: UIView { // Define the view's delegate. weak var delegate: SomeViewDelegate? // Assuming you already have a button. var button: UIButton! // Once your view & button has been initialized,configure the button's target. func configureButton() { // Set your target self.button.addTarget(self,action: #selector(someButtonPressed(_:)),for: .touchUpInside) } @objc func someButtonPressed(_ sender: UIButton) { delegate?.buttonWasPressed() } } // Conform to the delegate protocol class SomeViewController: UIViewController,SomeViewDelegate { var someView: SomeView! func buttonWasPressed() { // UIViewController can handle SomeView's button press. } }
另外,这是一个使用闭包而不是委托的快速示例. (这也可以使用块在ObjC中实现.)
// Use typeAlias to define closure typealias ButtonPressedHandler = () -> Void class SomeView: UIView { // Define the view's delegate. var pressedHandler: ButtonPressedHandler? // Assuming you already have a button. var button: UIButton! // Once your view & button has been initialized,for: .touchUpInside) } @objc func someButtonPressed(_ sender: UIButton) { pressedHandler?() } } class SomeViewController: UIViewController { var someView: SomeView! // Set the closure in the ViewController func configureButtonHandling() { someView.pressedHandler = { // UIViewController can handle SomeView's button press. } } }