在iOS 8中动态调整inputAccessoryView的大小

Question

基本上我试图在inputAccessoryView属性中创建一个调整大小的UITextView.

我有一个viewController,方法canBecomeFirstResponder返回true,一个视图我通过自定义类(从XIB获取)实例化.在这个视图中是一个UITextView.

我尝试从该类的内部调整完整的inputAccessoryView.我尝试了几个方面:直接设置框架,尝试使用高度约束.它似乎只调整了一半:

这基本上就是我想要的(有或没有自动布局,但在iOS 7/8 +中工作):

class MessageInputAccessory: UIView, UITextViewDelegate
{
    @IBOutlet weak var textView: UITextView!

    func textViewDidChange(textView: UITextView)
    {
        var contentSize = textView.sizeThatFits(CGSizeMake(textView.frame.size.width, CGFloat.max))

        self.frame.size.height = contentSize.height + 20

        self.textView.reloadInputViews()
    }
}

我发现这篇文章:在iOS 8中更改inputAccessoryView的框架.声明正在创建自动创建的约束.问题是,它不会为我创造约束.禁止或启用autolayout(也通过setTranslatesAutoresizingMaskIntoConstraints()).

Answer 1

它适用于iOS7/iOS8:

class MessageInputAccessory: UIView, UITextViewDelegate {
    private var textView: UITextView!
    private var heightConstraint: NSLayoutConstraint?

    override init(frame: CGRect) {
        super.init(frame: frame)

        commonInit()
    }

    required init(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)

        commonInit()
    }

    func commonInit() {
        self.userInteractionEnabled = true

        textView = UITextView()
        textView.delegate = self
        textView.bounces = false
        textView.scrollEnabled = false
        textView.layer.cornerRadius = 5
        textView.layer.borderWidth = 1
        textView.layer.borderColor = UIColor.blueColor().CGColor

        self.addSubview(textView)
    }

    override func layoutSubviews() {
        super.layoutSubviews()

        textView.frame = self.bounds
    }

    override func addConstraint(constraint: NSLayoutConstraint) {
        self.heightConstraint = constraint

        super.addConstraint(constraint)
    }

    func textViewDidChange(textView: UITextView) {
        var contentSize = textView.sizeThatFits(CGSizeMake(textView.frame.size.width, CGFloat.max))
        self.frame.size.height = contentSize.height

        if let heightConstraint = self.heightConstraint {
            heightConstraint.constant = self.frame.size.height
        }

        self.textView.reloadInputViews()
    }
}

编辑:这也适用于xib(iOS7/iOS8):

class MessageInputAccessory: UIView, UITextViewDelegate {
    @IBOutlet var textView: UITextView!
    @IBOutlet var textViewHeightConstraint: NSLayoutConstraint!
    private var heightConstraint: NSLayoutConstraint?

    override func awakeFromNib() {
        textView.layer.cornerRadius = 5
        textView.layer.borderWidth = 1
        textView.layer.borderColor = UIColor.blueColor().CGColor
    }

    override func layoutSubviews() {
        textViewHeightConstraint.constant = self.bounds.size.height

        super.layoutSubviews()
    }

    override func addConstraint(constraint: NSLayoutConstraint) {
        if constraint.firstItem === self {
            self.heightConstraint = constraint
        }

        super.addConstraint(constraint)
    }

    override func addConstraints(constraints: [AnyObject]) {
        super.addConstraints(constraints)
    }

    func textViewDidChange(textView: UITextView) {
        var contentSize = textView.sizeThatFits(CGSizeMake(textView.frame.size.width, CGFloat.max))
        self.frame.size.height = contentSize.height

        if let heightConstraint = self.heightConstraint {
            heightConstraint.constant = self.frame.size.height
        }

        self.textView.reloadInputViews()
    }

    override func intrinsicContentSize() -> CGSize {
        return self.bounds.size;
    }
}

有我的xib:

这不是一个很好的解决方案,但它的工作原理..请告诉我你是否知道更好的方法.