我是否必须使用代码执行此操作,或者检查器中是否存在我缺少的内容?
Unlike UIButton
, a UITextField
does not have a highlighted state. If you want to change the color of the textfield when it receives focus, you can use the UITextFieldDelegate
's
- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField
This will be called when the control first receives focus. From there you can change the background and/or text color. Once focus leaves the control, you can use
- (BOOL)textFieldShouldEndEditing:(UITextField *)textField
to reset the colors.
In Swift 2, you can use the delegate functions like below,
class CustomTextField: UITextField, UITextFieldDelegate{
init(){
super.init(frame: CGRectMake(0, 0, 0, 0))
self.delegate = self // SETTING DELEGATE TO SELF
}
func textFieldDidBeginEditing(textField: UITextField) {
textField.backgroundColor = UIColor.greenColor() // setting a highlight color
}
func textFieldDidEndEditing(textField: UITextField) {
textField.backgroundColor = UIColor.whiteColor() // setting a default color
}
}
If you still want to be able to use other delegate functions in you ViewController, I recommend you to add this:
override weak var delegate: UITextFieldDelegate? {
didSet {
if delegate?.isKindOfClass(YourTextField) == false {
// Checks so YourTextField (self) doesn't set the textFieldDelegate when assigning self.delegate = self
textFieldDelegate = delegate
delegate = self
}
}
}
// This delegate will actually be your public delegate to the view controller which will be called in your overwritten functions
private weak var textFieldDelegate: UITextFieldDelegate?
class YourTextField: UITextField, UITextFieldDelegate {
init(){
super.init(frame: CGRectZero)
self.delegate = self
}
func textFieldDidBeginEditing(textField: UITextField) {
textField.backgroundColor = UIColor.blackColor()
textFieldDelegate?.textFieldDidBeginEditing?(textField)
}
func textFieldDidEndEditing(textField: UITextField) {
textField.backgroundColor = UIColor.whiteColor()
textFieldDelegate?.textFieldDidBeginEditing?(textField)
}
}
This way your view controller doesn't need to know that you have overwritted the delegate and you can implement UITextFieldDelegate functions in your view controller.
let yourTextField = YourTextField()
yourTextField.delegate = self
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