设置UITextView的大小和对齐方式

Question

我在设置包含单个数字的UITextView时遇到问题。我希望视图很小，文本在水平和垂直方向都在中心。

实例化视图：

let setNumberView: UITextView = {
        let view = UITextView(frame: CGRect(x: 0, y: 0, width: heightForView(text: "8", font: UIFont.systemFont(ofSize: 12), width: 25), height: heightForView(text: "8", font: UIFont.systemFont(ofSize: 12), width: 25)))
        view.text = "1"
        view.backgroundColor = .white
        view.translatesAutoresizingMaskIntoConstraints = false
        print("FONT SIZE: \(view.font?.pointSize)")
        return view
    }()

设置约束：

/* setNumberView */

        let setDiameter = heightForView(text: "8", font: UIFont.systemFont(ofSize: 12), width: 25)

        addConstraintsWithFormat("H:|-4-[v0]", views: setNumberView)
        addConstraint(NSLayoutConstraint(item: setNumberView, attribute: .centerY, relatedBy: .equal, toItem: self, attribute: .centerY, multiplier: 1, constant: 0))
        //height
        addConstraint(NSLayoutConstraint(item: setNumberView, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: setDiameter))
        //width
        addConstraint(NSLayoutConstraint(item: setNumberView, attribute: .width, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: setDiameter))

但我留下了这个：

我的目标是让白色框中的“1”水平和垂直居中。

以下是我获得高度/宽度的方法：

func heightForView(text:String, font:UIFont, width:CGFloat) -> CGFloat{
    let label:UILabel = UILabel(frame: CGRect(x: 0, y: 0, width: width, height: CGFloat.greatestFiniteMagnitude))
    label.numberOfLines = 0
    label.lineBreakMode = NSLineBreakMode.byWordWrapping
    label.font = font
    label.text = text
    label.sizeToFit()

    return label.frame.height
}

Answer 1

试试这个：

textView.textContainerInset = UIEdgeInsets.zero
textView.textContainer.lineFragmentPadding = 0