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UITextView我希望在包含一些文本的内部绘制一条可自定义的线（使用NSAttributedString）

这是我尝试过的

NSString *unicodeStr = [NSString stringWithFormat:@"%C%C%C", 0x00A0, 0x0009, 0x00A0]; //nbsp, tab, nbsp
NSMutableAttributedString *str = [[NSMutableAttributedString alloc] initWithString:unicodeStr];
NSRange strRange = NSMakeRange(0, str.length);

NSMutableParagraphStyle *const tabStyle = [[NSMutableParagraphStyle alloc] init];
tabStyle.headIndent = 16; //padding on left and right edges
tabStyle.firstLineHeadIndent = 16;
tabStyle.tailIndent = -16;
NSTextTab *listTab = [[NSTextTab alloc] initWithTextAlignment:NSTextAlignmentCenter location:40 options:@{}]; //this is how long I want the line to be
tabStyle.tabStops = @[listTab];
[str  addAttribute:NSParagraphStyleAttributeName value:tabStyle range:strRange];
[str addAttribute:NSStrikethroughStyleAttributeName value:[NSNumber numberWithInt:2] range:strRange];

但是，无论我为制表位位置（在本例中为 40）和 tailIndent（此处为 -16）提供什么值，该行仅尊重 headIndent 并跨越整个 UITextView 宽度（当然减去 headIndent）。

编辑- 我很确定问题是因为我没有使用正确的 unicode 字符（尽管它们似乎是合乎逻辑的选择）。万一这给了某人一个提示，如果我在第二个 nbsp 之后添加一个空格，即接近尾声，则标签限制为单个标签长度

4

3 回答 3

2

是你预期的结果吗？

在此处输入图像描述 在此处输入图像描述

你可以试试这个：

NSTextTab *listTab = [[NSTextTab alloc] initWithTextAlignment:NSTextAlignmentCenter location:self.textView.frame.size.width - tabStyle.firstLineHeadIndent + tabStyle.tailIndent options:@{}];

这是完整的代码：

- (void) viewDidAppear:(BOOL)animated {
  [super viewDidAppear:animated];
  NSString *unicodeStr = @"\n\u00a0\t\t\n";
  NSMutableAttributedString *str = [[NSMutableAttributedString alloc] initWithString:unicodeStr];
  NSRange strRange = NSMakeRange(0, str.length);

  NSMutableParagraphStyle *const tabStyle = [[NSMutableParagraphStyle alloc] init];
  tabStyle.headIndent = 16; //padding on left and right edges
  tabStyle.firstLineHeadIndent = 16;
  tabStyle.tailIndent = -70;
  NSTextTab *listTab = [[NSTextTab alloc] initWithTextAlignment:NSTextAlignmentCenter location:self.textView.frame.size.width - tabStyle.headIndent + tabStyle.tailIndent options:@{}]; //this is how long I want the line to be
  tabStyle.tabStops = @[listTab];
  [str  addAttribute:NSParagraphStyleAttributeName value:tabStyle range:strRange];
  [str addAttribute:NSStrikethroughStyleAttributeName value:[NSNumber numberWithInt:2] range:strRange];

  NSAttributedString *htmlStr = [[NSAttributedString alloc] initWithData:[@"<h1>Lorem ipsum dolor sit er elit lamet</h1>" dataUsingEncoding:NSUnicodeStringEncoding] options:@{ NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType } documentAttributes:nil error:nil];

  [str insertAttributedString:htmlStr atIndex:0];
  [str appendAttributedString:htmlStr];

  self.textView.attributedText = str;
}
于 2016-03-18T07:39:26.127 回答
1

这是我为解决相同问题所做的工作。它使用一个子类NSTextTab：

import UIKit

class RightAnchoredTextTab : NSTextTab {
    weak var textContainer : NSTextContainer!

    required init(textAlignment alignment: NSTextAlignment, location loc: CGFloat, options: [String : AnyObject], textContainer aTextContainer : NSTextContainer) {
        super.init(textAlignment: alignment, location: loc, options: options)
        textContainer = aTextContainer
    }

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

    override var location: CGFloat {
        get {
           return textContainer.size.width-textContainer.lineFragmentPadding*2-super.location
        }
    }
}

以及与其他解决方案类似的位：

func horizontalLine(indent : CGFloat = 30, width : CGFloat = 1) -> NSAttributedString
{
    let paragraphStyle = NSMutableParagraphStyle()

    paragraphStyle.tabStops = []
    paragraphStyle.addTabStop(NSTextTab(textAlignment: .Left, location: indent, options: [:]))
    paragraphStyle.addTabStop(RightAnchoredTextTab(textAlignment: .Right, location: indent, options: [:], textContainer : textView.textContainer))
    paragraphStyle.alignment = .Left

    let attributes = [NSParagraphStyleAttributeName : paragraphStyle, NSStrikethroughStyleAttributeName : width]

    textView.backgroundColor = UIColor.yellowColor()
    let ZeroWidthNonBreakingSpace = "\u{FEFF}"
    return  NSAttributedString(string: "\t\(ZeroWidthNonBreakingSpace)\t\(ZeroWidthNonBreakingSpace)\n", attributes:  attributes)
}

几点注意事项：

  • 它可能只适用于单个方形文本容器。
  • NSTextContainer有一个lineFragmentPadding。如果您都想知道为什么必须将右对齐制表符缩进 10，那就是它：默认值为 5。
  • 在文本前面加上前缀\n意味着没有删除线。不知道为什么。
  • 当边界发生变化时，此解决方案与旋转等一起再次UITextView调用。NSTextTab.location
于 2016-04-30T15:36:08.113 回答
0

对于斯威夫特 5，

    let unicodeStr = "\n\u{00a0}\t\t\n"
    let str = NSMutableAttributedString(string: unicodeStr)
    let strRange = NSRange(location: 0, length: str.length)

    let tabStyle = NSMutableParagraphStyle()
    tabStyle.headIndent = 0 //padding on left and right edges
    tabStyle.firstLineHeadIndent = 0
    //tabStyle.tailIndent = -16
    let listTab = NSTextTab(textAlignment: .center, location: textView.frame.size.width-10, options: [:]) //this is how long I want the line to be
    tabStyle.tabStops = [listTab]
    str.addAttribute(.paragraphStyle, value: tabStyle, range: strRange)
    str.addAttribute(.strikethroughStyle, value: NSNumber(value: 2), range: strRange)
    str.addAttribute(.strikethroughColor, value: UIColor.label, range: strRange)
    str.addAttribute(NSAttributedString.Key.font, value: self.currentFont, range: strRange)
    str.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.label, range: strRange)


    textView.textStorage.append(str)

    //To set cursor end of document
    let endPosition = self.textView.endOfDocument
    self.textView.selectedTextRange = self.textView.textRange(from: endPosition, to: endPosition)
于 2020-10-26T12:52:27.627 回答