用两行更改此自定义导航栏中的文本颜色？

Question

我目前有一个启用了大标题的导航栏，它还支持两行，在 viewdidLoad 中使用以下代码：

navigationController?.navigationBar.prefersLargeTitles = true
        self.navigationController?.navigationItem.largeTitleDisplayMode = .automatic

        let date = Date()
        let formatter = DateFormatter()
        formatter.dateFormat = "MMMM dd"
        let result = formatter.string(from: date)




        self.title = “This is a Test\n\(result)"



        var count = 0
        for item in(self.navigationController?.navigationBar.subviews)! {
            for sub in item.subviews{
                if sub is UILabel{
                    if count == 1 {
                        break;
                    }
                    let titleLab :UILabel = sub as! UILabel
                    titleLab.numberOfLines = 0
                    titleLab.text = self.title
                    titleLab.lineBreakMode = .byWordWrapping
                    count = count + 1
                }
            }

        }
        self.navigationController?.navigationBar.layoutSubviews()
        self.navigationController?.navigationBar.layoutIfNeeded()

如何改变每行文字的字体和颜色 self.title = “This is a Test\n\(result)"

例如，使 "This is a Test" 黑色和 "(result)" 灰色。

Answer 1

首先从 string 创建一个 attributedString 并添加所需的 attributes，即

let result = "13 June 2019"
let text = "This is a Test\n\(result)"
let arr = text.components(separatedBy: .newlines)

let attributedString = NSMutableAttributedString()
for (index, str) in arr.enumerated() {
    let attrStr = NSMutableAttributedString(string: str)
    if index == 0 {
        attrStr.addAttribute(.foregroundColor, value: UIColor.red, range: NSRange(location: 0, length: str.count))
        attrStr.addAttribute(.font, value: UIFont.systemFont(ofSize: 12.0, weight: .bold), range: NSRange(location: 0, length: str.count))
    } else {
        attrStr.addAttribute(.foregroundColor, value: UIColor.blue, range: NSRange(location: 0, length: str.count))
        attrStr.addAttribute(.font, value: UIFont.systemFont(ofSize: 12.0), range: NSRange(location: 0, length: str.count))
    }
    if index < arr.count {
        attributedString.append(NSAttributedString(string: "\n"))
    }
    attributedString.append(attrStr)
}

创建一个 UILabel 并将此 attributedString 添加为 label 的 attributedText。

let label = UILabel()
label.textAlignment = .center
label.numberOfLines = 0
label.attributedText = attributedString

将此 label 添加为 navigationItem 的 titleView，即

self.navigationItem.titleView = label

用两行更改此自定义导航栏中的文本颜色？

Change the color of text in this custom navigation bar with two rows?

uinavigationbar

swift