What methods or tools are used to handle key press or button press events?

In iOS, the following methods and tools are commonly used to handle key press or button events:

• UIButton and target-action: buttons (UIButton) can be linked to methods via the target-action mechanism. When pressed, the linked method is called.

let button = UIButton(type: .system)
button.addTarget(self, action: #selector(buttonPressed), for: .touchUpInside)

@objc func buttonPressed() {
    print("Button pressed")
}

• Handling hardware keyboard key presses (for example, on iPad): you can override UIResponder methods such as keyCommands and pressesBegan.

override var keyCommands: [UIKeyCommand]? {
    return [
        UIKeyCommand(input: "a", modifierFlags: [], action: #selector(handleAKey))
    ]
}

@objc func handleAKey() {
    print("A key pressed")
}

Thus, target-action is used for buttons, and UIResponder methods are used for hardware keys.