iphone UITextView设置行间距

时间：2010-11-25 13:26:52

标签： ios iphone uitextview

如何在UITextView中增加行空间，使其在iPhone中看起来像“Notes”应用程序？

8 个答案:

答案 0 :(得分：25)

现在在iOS6上，有可能使用NSParagraphStyle，但它的记录非常糟糕，似乎很少工作。

我目前正在这样做：

UITextView *lab = [LocalTexts objectAtIndex:j];

NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineHeightMultiple = 50.0f;
paragraphStyle.maximumLineHeight = 50.0f;
paragraphStyle.minimumLineHeight = 50.0f;

NSString *string = lab.text;
NSDictionary *ats = @{
    NSFontAttributeName: [UIFont fontWithName:@"DIN Medium" size:16.0f],
    NSParagraphStyleAttributeName: paragraphStyle, 
};

lab.attributedText = [[NSAttributedString alloc] initWithString:string attributes:ats];

问题是，当您设置字体时，行高会停止工作。很奇怪。我还没有找到解决办法。

此外，您可以创建自定义的Attributed CoreText视图...但它更具技术性，您可以找到它是如何完成的演示here

我希望有所帮助。

答案 1 :(得分：14)

使用Swift 4和iOS 11，根据您的需要，您可以选择以下 3个实施中的一个来解决您的问题。

＃1。使用String和UIFontDescriptorSymbolicTraits traitLooseLeading属性

traitLooseLeading有以下声明：

  

字体使用更宽松的前导值。

static var traitLooseLeading: UIFontDescriptorSymbolicTraits { get }

以下代码显示了如何实现traitLooseLeading，以便为UItextView提供更宽松的字体。

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        let textView = UITextView()
        view.addSubview(textView)

        textView.text = """
        Lorem ipsum
        Dolor sit amet,
        consectetur adipiscing elit
        """

        if let fontDescriptor = UIFontDescriptor
            .preferredFontDescriptor(withTextStyle: UIFontTextStyle.body)
            .withSymbolicTraits(UIFontDescriptorSymbolicTraits.traitLooseLeading) {
            let looseLeadingFont = UIFont(descriptor: fontDescriptor, size: 0)
            textView.font = looseLeadingFont
        }

        // Layout textView
        textView.translatesAutoresizingMaskIntoConstraints = false
        textView.topAnchor.constraint(equalTo: view.readableContentGuide.topAnchor).isActive = true
        textView.bottomAnchor.constraint(equalTo: view.readableContentGuide.bottomAnchor).isActive = true
        textView.leadingAnchor.constraint(equalTo: view.readableContentGuide.leadingAnchor).isActive = true
        textView.trailingAnchor.constraint(equalTo: view.readableContentGuide.trailingAnchor).isActive = true
    }

}

＃2。使用NSAttributedString和NSMutableParagraphStyle lineSpacing属性

lineSpacing有以下声明：

  

一行片段底部与下一行片段顶部之间的距离。

var lineSpacing: CGFloat { get set }

以下代码显示了如何实现lineSpacing，以便为UItextView中的某些属性文本设置特定的行间距。

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        let string = """
        Lorem ipsum
        Dolor sit amet,
        consectetur adipiscing elit
        """

        let paragraphStyle = NSMutableParagraphStyle()
        paragraphStyle.lineSpacing = 15

        let attributes: [NSAttributedStringKey: Any] = [NSAttributedStringKey.paragraphStyle: paragraphStyle]
        let attributedString = NSAttributedString(string: string, attributes: attributes)

        let textView = UITextView()
        textView.attributedText = attributedString
        view.addSubview(textView)

        // Layout textView
        textView.translatesAutoresizingMaskIntoConstraints = false
        textView.topAnchor.constraint(equalTo: view.readableContentGuide.topAnchor).isActive = true
        textView.bottomAnchor.constraint(equalTo: view.readableContentGuide.bottomAnchor).isActive = true
        textView.leadingAnchor.constraint(equalTo: view.readableContentGuide.leadingAnchor).isActive = true
        textView.trailingAnchor.constraint(equalTo: view.readableContentGuide.trailingAnchor).isActive = true
    }

}

＃3。使用String和NSLayoutManagerDelegate协议layoutManager(_:lineSpacingAfterGlyphAt:withProposedLineFragmentRect:)方法

layoutManager(_:lineSpacingAfterGlyphAt:withProposedLineFragmentRect:)有以下声明：

  

返回以给定的字形索引结束的行之后的间距。 [...]在布置每一行时发送此消息，以使布局管理器委托能够自定义行的形状。

optional func layoutManager(_ layoutManager: NSLayoutManager, lineSpacingAfterGlyphAt glyphIndex: Int, withProposedLineFragmentRect rect: CGRect) -> CGFloat

以下代码显示了如何实现layoutManager(_:lineSpacingAfterGlyphAt:withProposedLineFragmentRect:) 为了使UItextView具有特定的行间距。

import UIKit

class ViewController: UIViewController, NSLayoutManagerDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()

        let textView = UITextView()
        textView.layoutManager.delegate = self
        view.addSubview(textView)

        textView.text = """
        Lorem ipsum
        Dolor sit amet,
        consectetur adipiscing elit
        """

        // Layout textView
        textView.translatesAutoresizingMaskIntoConstraints = false
        textView.topAnchor.constraint(equalTo: view.readableContentGuide.topAnchor).isActive = true
        textView.bottomAnchor.constraint(equalTo: view.readableContentGuide.bottomAnchor).isActive = true
        textView.leadingAnchor.constraint(equalTo: view.readableContentGuide.leadingAnchor).isActive = true
        textView.trailingAnchor.constraint(equalTo: view.readableContentGuide.trailingAnchor).isActive = true
    }

    // MARK: - NSLayoutManagerDelegate

    func layoutManager(_ layoutManager: NSLayoutManager, lineSpacingAfterGlyphAt glyphIndex: Int, withProposedLineFragmentRect rect: CGRect) -> CGFloat {
        return 15
    }

}

作为上一代码的替代方法，以下代码显示了如何实现layoutManager(_:lineSpacingAfterGlyphAt:withProposedLineFragmentRect:) 在UITextView子类中。

import UIKit

class LineSpacingTextView: UITextView, NSLayoutManagerDelegate {

    override init(frame: CGRect, textContainer: NSTextContainer?) {
        super.init(frame: frame, textContainer: textContainer)
        layoutManager.delegate = self
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    // MARK: - NSLayoutManagerDelegate

    func layoutManager(_ layoutManager: NSLayoutManager, lineSpacingAfterGlyphAt glyphIndex: Int, withProposedLineFragmentRect rect: CGRect) -> CGFloat {
        return 15
    }

}

import UIKit

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()

        let textView = LineSpacingTextView()
        view.addSubview(textView)

        textView.text = """
        Lorem ipsum
        Dolor sit amet,
        consectetur adipiscing elit
        """

        // Layout textView
        textView.translatesAutoresizingMaskIntoConstraints = false
        textView.topAnchor.constraint(equalTo: view.readableContentGuide.topAnchor).isActive = true
        textView.bottomAnchor.constraint(equalTo: view.readableContentGuide.bottomAnchor).isActive = true
        textView.leadingAnchor.constraint(equalTo: view.readableContentGuide.leadingAnchor).isActive = true
        textView.trailingAnchor.constraint(equalTo: view.readableContentGuide.trailingAnchor).isActive = true
    }

}

答案 2 :(得分：11)

要更改行间距：

NSString *textViewText =self.myTextView.text;

NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:textViewText];
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineSpacing = 30;
NSDictionary *dict = @{NSParagraphStyleAttributeName : paragraphStyle };
[attributedString addAttributes:dict range:NSMakeRange(0, [textViewText length])];

self.myTextView.attributedText = attributedString;

答案 3 :(得分：9)

查看UITextView的文档就足以确定该控件不支持更改行间距。

适用于iOS 6及以上版本：

有可能使用NSParagraphStyle 

NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineHeightMultiple = 50.0f;
paragraphStyle.maximumLineHeight = 50.0f;
paragraphStyle.minimumLineHeight = 50.0f;
NSString *string = @"your paragraph here";
NSDictionary *attribute = @{
   NSParagraphStyleAttributeName : paragraphStyle, 
   };
[textview setFont:[uifont fontwithname:@"Arial" size:20.0f]];
textview.attributedText = [[NSAttributedString alloc] initWithString:string attributes:attribute];

答案 4 :(得分：5)

Swift 2.2 

let paragraphStyle: NSMutableParagraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineHeightMultiple = 20.0
paragraphStyle.maximumLineHeight = 20.0
paragraphStyle.minimumLineHeight = 20.0
let ats = [NSFontAttributeName: UIFont(name: "Helvetica Neue", size: 11.0)!, NSParagraphStyleAttributeName: paragraphStyle]
cell.textView.attributedText = NSAttributedString(string: "you string here", attributes: ats)

答案 5 :(得分：4)

如果最终结果是增加行间距，则可以直接在界面构建器中执行此操作。将Text属性设置为“Attributed”，然后单击右侧的....设置间距属性应该正确更新行间距。

答案 6 :(得分：1)

在以上几个答案中，属性lineHeightMultiple被滥用：

paragraphStyle.lineHeightMultiple = 50.0f;

官方文档lineHeightMultiple之后是乘数，而不是字符串的绝对高度：

  

接收器的自然线高度乘以   这个因素（如果是正面的）在被最小值和最小值约束之前   最大线高。此属性的默认值为0.0。   https://developer.apple.com/library/prerelease/ios/documentation/Cocoa/Reference/ApplicationKit/Classes/NSParagraphStyle_Class/index.html#//apple_ref/occ/instp/NSParagraphStyle/maximumLineHeight

因此，下面的代码：

paragraphStyle.lineHeightMultiple = 50.0f;
paragraphStyle.maximumLineHeight = 50.0f;
paragraphStyle.minimumLineHeight = 50.0f;

相当于

paragraphStyle.lineHeight = 50.0f

答案 7 :(得分：0)

 NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
   paragraphStyle.lineHeightMultiple = 50.0f;
   paragraphStyle.maximumLineHeight = 50.0f;
   paragraphStyle.minimumLineHeight = 50.0f;
     NSString *string = @"if you want reduce or increase space between lines in uitextview ,you can do this with this,but donot set font on this paragraph , set this on uitextveiw.";

    NSDictionary *ats = @{
   NSParagraphStyleAttributeName : paragraphStyle, 
     };

    [textview setFont:[uifont fontwithname:@"Arial" size:20.0f]];
    textview.attributedText = [[NSAttributedString alloc] initWithString:string attributes:ats];
相关问题
最新问题