iOS 8中具有动态高度的自定义inputView

我的自定义inputView for UITextFields有些麻烦.根据用户需要在UITextField中输入的文本,inputView仅显示所需的字母.这意味着对于短文本,只有一行字母的inputView就足够了,较长的文本可能需要2行甚至3行,因此inputView的高度是变量.

由于我期望性能更好,因此每个textField只使用一个inputView实例.这样创建必须只发生一次,这使得有时需要直接访问inputView更容易. inputView设置在 – (BOOL)textFieldShouldBeginEditing：(UITextField *)textField中,设置其所需的高度并将显示.

这非常有效,但不适用于iOS8.有一些包含inputView的系统视图在更改时不会更新其框架以匹配inputView的边界(第一次工作).

我知道可以通过每个textField使用我的inputView的一个实例来修复.但我问是否有一种推荐/更好的方法来调整框架或将其更改报告给包含视图.也许这是一个iOS8错误,可以修复直到发布？

以下是重现问题的示例代码：

CustomInputView

@implementation CustomInputView

+ (CustomInputView*)sharedInputView{
    static CustomInputView *sharedInstance;
    static dispatch_once_t oncetoken;
    dispatch_once(&oncetoken,^{
        sharedInstance = [[CustomInputView alloc] init];
    });
    return sharedInstance;
}

- (id)init
{
    self = [super init];
    if (self) {
        self.backgroundColor = [UIColor greenColor];
    }
    return self;
}

- (void)setupForTextField:(UITextField*)textField{
    CGFloat height;

    if(textField.tag == 1){
        height = 100;
    }else height = 50;

    self.frame = CGRectMake(0,320,height);
}
@end

TestViewController代码

- (void)viewDidLoad
{
    [super viewDidLoad];

    UITextField *tf = [[UITextField alloc] initWithFrame:CGRectMake(15,50,290,30)];
    tf.text = @"bigKeyboard";
    tf.inputView = [CustomInputView sharedInputView];
    tf.layer.borderWidth = 1;
    tf.layer.borderColor = [UIColor lightGrayColor].CGColor;
    tf.delegate = self;
    tf.tag = 1;
    [self.view addSubview:tf];

    tf = [[UITextField alloc] initWithFrame:CGRectMake(15,100,30)];
    tf.text = @"smallKeyboard";
    tf.inputView = [CustomInputView sharedInputView];
    tf.layer.borderWidth = 1;
    tf.layer.borderColor = [UIColor lightGrayColor].CGColor;
    tf.delegate = self;
    tf.tag = 2;
    [self.view addSubview:tf];

    UIButton *button = [UIButton buttonWithType:UIButtonTypeSystem];
    [button setTitle:@"dismissKeyboard" forState:UIControlStatenormal];
    [button addTarget:self action:@selector(endEditing) forControlEvents:UIControlEventTouchUpInside];
    button.frame = CGRectMake(15,150,30);
    [self.view addSubview:button];
}

- (void)endEditing{
    [self.view endEditing:YES];
}

- (BOOL)textFieldShouldBeginEditing:(UITextField *)textField{
    [[CustomInputView sharedInputView] setupForTextField:textField];
    return YES;
}

class CustomInputView: UIInputView {
    var intrinsicHeight: CGFloat = 200 {
        didSet {
            self.invalidateIntrinsicContentSize()
        }
    }

    init() {
        super.init(frame: CGRect(),inputViewStyle: .keyboard)
        self.translatesAutoresizingMaskIntoConstraints = false
    }

    required init?(coder: NSCoder) {
        super.init(coder: coder)
        self.translatesAutoresizingMaskIntoConstraints = false
    }

    override var intrinsicContentSize: CGSize {
        return CGSize(width: UIViewNoIntrinsicmetric,height: self.intrinsicHeight)
    }
}

class ViewController: UIViewController {
    @IBOutlet weak var textView: UITextView!

    override func viewDidLoad() {
        super.viewDidLoad()

        textView.becomeFirstResponder()

        let inputView = CustomInputView()
        // To make the view's size more clear.
        inputView.backgroundColor = UIColor(red: 0.5,green: 1,blue: 0.5,alpha: 1)
        textView.inputView = inputView

        // To demonstrate a change to the view's intrinsic height.
        dispatchQueue.main.asyncAfter(deadline: dispatchTime.Now() + .seconds(2)) {
            inputView.intrinsicHeight = 400
        }
    }
}