ios - iOS7 TextKit：项目符号对齐

Question

我正在编写一个仅适用于 iOS 7 的应用程序，并且我正在尝试在不可编辑的 UITextView 中对项目符号点进行适当的格式化。

只需插入一个项目符号字符就很容易了，但当然不会出现左缩进。在 iOS 7 上，在项目符号点后设置左缩进的最简单方法是什么？

提前致谢，

坦率

Answer 1

所以我环顾四周，这是从 Duncan 的答案中提取的最小代码，以使其工作：

NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:yourLabel.text];

NSMutableParagraphStyle *paragrahStyle = [[NSMutableParagraphStyle alloc] init];
[paragrahStyle setParagraphSpacing:4];
[paragrahStyle setParagraphSpacingBefore:3];
[paragrahStyle setFirstLineHeadIndent:0.0f];  // First line is the one with bullet point
[paragrahStyle setHeadIndent:10.5f];    // Set the indent for given bullet character and size font

[attributedString addAttribute:NSParagraphStyleAttributeName value:paragrahStyle
                         range:NSMakeRange(0, [self.descriptionLabel.text length])];

yourLabel.attributedText = attributedString;

这是我的应用程序中的结果：

Answer 2

下面是我用来设置项目符号段落的代码。这直接来自工作应用程序，用于将样式应用于整个段落，以响应用户单击格式按钮。我试图放入所有依赖的方法，但可能错过了一些。

请注意，我以厘米为单位设置了大多数缩进，因此在列表末尾使用了转换函数。

我还在检查是否存在制表符（iOS 上没有制表键！）并自动插入破折号和制表符。

如果您只需要段落样式，那么请查看下面设置 firstLineIndent 等的最后几个方法。

请注意，这些调用都包含在[textStorage beginEditing/endEditing]. 尽管下面的 (IBAction) 方法没有被 UI 对象直接调用。

        - (IBAction) styleBullet1:(id)sender
        {
            NSRange charRange = [self rangeForUserParagraphAttributeChange];
            NSTextStorage *myTextStorage = [self textStorage];

            // Check for "-\t" at beginning of string and add if not found
            NSAttributedString *attrString = [myTextStorage attributedSubstringFromRange:charRange];
            NSString *string = [attrString string];

            if ([string rangeOfString:@"\t"].location == NSNotFound) {
                NSLog(@"string does not contain tab so insert one");
                NSAttributedString * aStr = [[NSAttributedString alloc] initWithString:@"-\t"];
                // Insert a bullet and tab
                [[self textStorage] insertAttributedString:aStr atIndex:charRange.location];

            } else {
                NSLog(@"string contains tab");
            }

            if ([self isEditable] && charRange.location != NSNotFound)
            {
                [myTextStorage setAttributes:[self bullet1Style] range:charRange];
            }
        }

        - (NSDictionary*)bullet1Style
        {
            return [self createStyle:[self getBullet1ParagraphStyle] font:[self normalFont] fontColor:[UIColor blackColor] underlineStyle:NSUnderlineStyleNone];

        }

        - (NSDictionary*)createStyle:(NSParagraphStyle*)paraStyle font:(UIFont*)font fontColor:(UIColor*)color underlineStyle:(int)underlineStyle
        {
            NSMutableDictionary *style = [[NSMutableDictionary alloc] init];
            [style setValue:paraStyle forKey:NSParagraphStyleAttributeName];
            [style setValue:font forKey:NSFontAttributeName];
            [style setValue:color forKey:NSForegroundColorAttributeName];
            [style setValue:[NSNumber numberWithInt: underlineStyle] forKey:NSUnderlineStyleAttributeName];

            FLOG(@" font is %@", font);

            return style;
        }

        - (NSParagraphStyle*)getBullet1ParagraphStyle
        {
            NSMutableParagraphStyle *para;
            para = [self getDefaultParagraphStyle];
            NSMutableArray *tabs = [[NSMutableArray alloc] init];
            [tabs addObject:[[NSTextTab alloc] initWithTextAlignment:NSTextAlignmentLeft location:[self ptsFromCMF:1.0] options:nil]];
            //[tabs addObject:[[NSTextTab alloc] initWithType:NSLeftTabStopType location:[self ptsFromCMF:1.0]]];
            [para setTabStops:tabs];
            [para setDefaultTabInterval:[self ptsFromCMF:2.0]];
            [para setFirstLineHeadIndent:[self ptsFromCMF:0.0]];
            //[para setHeaderLevel:0];
            [para setHeadIndent:[self ptsFromCMF:1.0]];
            [para setParagraphSpacing:3];
            [para setParagraphSpacingBefore:3];
            return para;
        }
    - (NSMutableParagraphStyle*)getDefaultParagraphStyle
    {
        NSMutableParagraphStyle *para;
        para = [[NSParagraphStyle defaultParagraphStyle]mutableCopy];
        [para setTabStops:nil];
        [para setAlignment:NSTextAlignmentLeft];
        [para setBaseWritingDirection:NSWritingDirectionLeftToRight];
        [para setDefaultTabInterval:[self ptsFromCMF:3.0]];
        [para setFirstLineHeadIndent:0];
        //[para setHeaderLevel:0];
        [para setHeadIndent:0.0];
        [para setHyphenationFactor:0.0];
        [para setLineBreakMode:NSLineBreakByWordWrapping];
        [para setLineHeightMultiple:1.0];
        [para setLineSpacing:0.0];
        [para setMaximumLineHeight:0];
        [para setMinimumLineHeight:0];
        [para setParagraphSpacing:6];
        [para setParagraphSpacingBefore:3];
        //[para setTabStops:<#(NSArray *)#>];
        [para setTailIndent:0.0];
        return para;
    }
-(NSNumber*)ptsFromCMN:(float)cm
{
    return [NSNumber numberWithFloat:[self ptsFromCMF:cm]];
}
-(float)ptsFromCMF:(float)cm
{
    return cm * 28.3464567;
}

Answer 3

这是我找到的最简单的解决方案：

let bulletList = UILabel()
let bulletListArray = ["line 1 - enter a bunch of lorem ipsum here so it wraps to the next line", "line 2", "line 3"]
let joiner = "\n"

var paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.headIndent = 10
paragraphStyle.firstLineHeadIndent = 0

let attributes = [NSParagraphStyleAttributeName: paragraphStyle]
let bulletListString = joiner.join(bulletListArray.map { "• \($0)" })

bulletList.attributedText = NSAttributedString(string: bulletListString, attributes: attributes)

理论是数组中的每个字符串都像“段落”一样，段落样式在第一行缩进 0，使用 map 方法添加一个项目符号。然后对于每行缩进 10 px（调整间距用于您的字体指标）

Answer 4

其他答案依赖于使用恒定值设置缩进大小。这意味着如果您要更改字体，则必须手动更新它，如果您使用的是动态类型，则无法正常工作。幸运的是，测量文本很容易。

假设您有一些文本和一些属性：

NSString *text = @"• Some bulleted paragraph";
UIFont *font = [UIFont preferredFontForTextStyle:UIFontTextStyleBody];
NSDictionary *attributes = @{NSFontAttributeName: font};

以下是如何测量项目符号并相应地创建段落样式：

NSString *bulletPrefix = @"• ";
CGSize size = [bulletPrefix sizeWithAttributes:attributes];
NSMutableParagraphStyle *paragraphStyle = [NSMutableParagraphStyle new];
paragraphStyle.headIndent = size.width;

我们将其插入到我们的属性中并创建属性字符串：

NSMutableDictionary *indentedAttributes = [attributes mutableCopy];
indentedAttributes[NSParagraphStyleAttributeName] = [paragraphStyle copy];
NSAttributedString *attributedString = [[NSAttributedString alloc] initWithString:text attributes:indentedAttributes];

Answer 5

斯威夫特 4

我做了一个扩展NSAttributedString，添加了一个方便的初始化器，它可以正确缩进不同类型的列表。

extension NSAttributedString {

    convenience init(listString string: String, withFont font: UIFont) {
        self.init(attributedListString: NSAttributedString(string: string), withFont: font)
    }

    convenience init(attributedListString attributedString: NSAttributedString, withFont font: UIFont) {
        guard let regex = try? NSRegularExpression(pattern: "^(\\d+\\.|[•\\-\\*])(\\s+).+$",
                                                   options: [.anchorsMatchLines]) else { fatalError() }
        let matches = regex.matches(in: attributedString.string, options: [],
                                    range: NSRange(location: 0, length: attributedString.string.utf16.count))
        let nsString = attributedString.string as NSString
        let mutableAttributedString = NSMutableAttributedString(attributedString: attributedString)

        for match in matches {
            let size = NSAttributedString(
                string: nsString.substring(with: match.range(at: 1)) + nsString.substring(with: match.range(at: 2)),
                attributes: [.font: font]).size()
            let indentation = ceil(size.width)
            let range = match.range(at: 0)

            let paragraphStyle = NSMutableParagraphStyle()

            if let style = attributedString.attribute(.paragraphStyle, at: 0, longestEffectiveRange: nil, in: range)
                as? NSParagraphStyle {
                paragraphStyle.setParagraphStyle(style)
            }

            paragraphStyle.tabStops = [NSTextTab(textAlignment: .left, location: indentation, options: [:])]
            paragraphStyle.defaultTabInterval = indentation
            paragraphStyle.firstLineHeadIndent = 0
            paragraphStyle.headIndent = indentation

            mutableAttributedString.addAttribute(.font, value: font, range: range)
            mutableAttributedString.addAttribute(.paragraphStyle, value: paragraphStyle, range: range)
        }

        self.init(attributedString: mutableAttributedString)
    }
}

示例用法：

每个项目符号后的空格数等无关紧要。该代码将根据您决定在项目符号后使用的制表符或空格数动态计算适当的缩进宽度。

如果属性字符串已经具有段落样式，则便利初始化程序将保留该段落样式的选项并应用它自己的一些选项。

支持的符号： •、-、*、后跟句点的数字（例如 8。）

Answer 6

你们都可以使用属性检查器来做这个简单的事情，选择缩进字段并做任何你想做的改变:)

Answer 7

基于thisispete的解决方案，更新到 Swift 4.2。

斯威夫特 4.2

let array = ["1st", "2nd", "3rd"]
let textView = UITextView()
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.firstLineHeadIndent = 0
paragraphStyle.headIndent = 12
let bulletListText = array.map { "• \($0)" }.joined(separator: "\n")
let attributes = [
    NSAttributedString.Key.paragraphStyle: paragraphStyle,
    NSAttributedString.Key.font: UIFont.systemFont(ofSize: 17.0)
]
textView.attributedText = NSAttributedString(string: bulletListText, attributes: attributes)

Answer 8

我基于 Lukas 实现做了一个快速的解决方案（目前是 Swift 2.3）。我对没有项目符号的行有一点问题，所以我做了扩展，所以你可以选择传递一个范围来应用段落样式。

extension String{

    func getAllignedBulletPointsMutableString(bulletPointsRange: NSRange = NSMakeRange(0, 0)) -> NSMutableAttributedString{

        let attributedString: NSMutableAttributedString = NSMutableAttributedString(string: self)
        let paragraphStyle = NSMutableParagraphStyle()
        paragraphStyle.paragraphSpacing = 0
        paragraphStyle.paragraphSpacingBefore = 0
        paragraphStyle.firstLineHeadIndent = 0
        paragraphStyle.headIndent = 7.5

        attributedString.addAttributes([NSParagraphStyleAttributeName: paragraphStyle], range: bulletPointsRange)
        return attributedString
    }

}