按下键盘中的返回键时,UITextView 不记得字体样式
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【中文标题】按下键盘中的返回键时,UITextView 不记得字体样式【英文标题】:UITextView not remembering the font styles when return key in keyboard is pressed 【发布时间】:2017-10-14 14:21:47 【问题描述】:我在情节提要中有一个 UITextView (文本属性已属性化,并选中允许编辑属性,选中,可编辑)。当用户按下按钮时,我想“激活”粗体字体。因此,无论用户从那里输入什么,都必须以粗体显示。当按下返回键时,我想转到下一行,UITextView 应该记住所有文本的属性。问题是按回车键后,所有字符都变为粗体。
这是我的代码。
var isBoldTyping: Bool = false
func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool
print("text: \(text)", range)
if text == "\n"
textView.text.append("\n")
if isBoldTyping
//textView.typingAttributes = [NSAttributedStringKey.font.rawValue: regularText]
isBoldTyping = false
if isBoldTyping
textView.textStorage.beginEditing()
textView.textStorage.addAttributes([NSAttributedStringKey.font: boldText], range: range)
print("Atttributed adding")
textView.textStorage.endEditing()
else
textView.textStorage.beginEditing()
textView.textStorage.addAttributes([NSAttributedStringKey.font: regularText], range: range)
print("Atttributed adding")
textView.textStorage.endEditing()
return true
我想要实现的另一个示例是 *** 编辑效果。当我按下“”图标时,我处于“可编码模式”。当在键盘中按下 enter 时,它会恢复正常。
regularText和boldText属性就是14号的系统字体。
【问题讨论】:
【参考方案1】:如果我清楚地了解您想要实现的目标,您只需要typingAttributes
。当\n
出现在replacementText
到typingAttributes
中时,您需要禁用粗体。我给你写一个小例子
class ViewController: UIViewController, UITextViewDelegate
let textView = UITextView()
let boldButton = UIButton(type: .system)
override func viewDidLoad()
super.viewDidLoad()
textView.translatesAutoresizingMaskIntoConstraints = false
textView.delegate = self
textView.typingAttributes = [NSAttributedStringKey.font.rawValue: UIFont.systemFont(ofSize: 14.0)]
view.addSubview(textView)
view.addConstraint(NSLayoutConstraint(item: view, attribute: .leading, relatedBy: .equal, toItem: textView, attribute: .leading, multiplier: 1.0, constant: 0.0))
view.addConstraint(NSLayoutConstraint(item: view, attribute: .top, relatedBy: .equal, toItem: textView, attribute: .top, multiplier: 1.0, constant: 0.0))
view.addConstraint(NSLayoutConstraint(item: view, attribute: .bottom, relatedBy: .equal, toItem: textView, attribute: .bottom, multiplier: 1.0, constant: 0.0))
view.addConstraint(NSLayoutConstraint(item: view, attribute: .trailing, relatedBy: .equal, toItem: textView, attribute: .trailing, multiplier: 1.0, constant: 0.0))
boldButton.setTitle("BOLD", for: .normal)
boldButton.addTarget(self, action: #selector(toggleBold), for: .touchUpInside)
boldButton.translatesAutoresizingMaskIntoConstraints = false
view.addSubview(boldButton)
view.addConstraint(NSLayoutConstraint(item: view, attribute: .leading, relatedBy: .equal, toItem: boldButton, attribute: .leading, multiplier: 1.0, constant: 0.0))
view.addConstraint(NSLayoutConstraint(item: boldButton, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1.0, constant: 64.0))
view.addConstraint(NSLayoutConstraint(item: view, attribute: .bottom, relatedBy: .equal, toItem: boldButton, attribute: .bottom, multiplier: 1.0, constant: 0.0))
view.addConstraint(NSLayoutConstraint(item: view, attribute: .trailing, relatedBy: .equal, toItem: boldButton, attribute: .trailing, multiplier: 1.0, constant: 0.0))
@objc func toggleBold()
boldButton.isSelected = !boldButton.isSelected
if boldButton.isSelected
textView.typingAttributes = [NSAttributedStringKey.font.rawValue: UIFont.boldSystemFont(ofSize: 14.0)]
else
textView.typingAttributes = [NSAttributedStringKey.font.rawValue: UIFont.systemFont(ofSize: 14.0)]
override func didReceiveMemoryWarning()
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool
if text.contains("\n") && boldButton.isSelected
toggleBold()
return true
【讨论】:
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