ios NSAttributedString 添加文本对齐

NSAttributedString add text alignment

提问by aryaxt

How can I add text alignment attribute to an NSAttributedString to center the text?

如何将文本对齐属性添加到 NSAttributedString 以将文本居中？

Edit: Am I doing anything wrong? It doesn't seem to change the alignment.

编辑：我做错了什么吗？它似乎没有改变对齐方式。

CTParagraphStyleSetting setting;
setting.spec = kCTParagraphStyleSpecifierAlignment;
setting.valueSize = kCTCenterTextAlignment;

CTParagraphStyleSetting settings[1] = {
    {kCTParagraphStyleSpecifierAlignment, sizeof(CGFloat), &setting},           
};

CTParagraphStyleRef paragraph = CTParagraphStyleCreate(settings, sizeof(setting));

NSMutableAttributedString *mutableAttributed = [[NSMutableAttributedString alloc] initWithAttributedString:self.attributedString];
[mutableAttributed addAttributes:[NSDictionary dictionaryWithObjectsAndKeys:(NSObject*)paragraph ,(NSString*) kCTParagraphStyleAttributeName, nil] range:_selectedRange];

采纳答案by omz

As NSAttributedStringis primarily used with Core Text on iOS, you have to use CTParagraphStyleinstead of NSParagraphStyle. There is no mutable variant.

由于NSAttributedString主要是用在iOS内核中使用的，你必须使用CTParagraphStyle替代NSParagraphStyle。没有可变的变体。

For example:

例如：

CTTextAlignment alignment = kCTCenterTextAlignment;

CTParagraphStyleSetting alignmentSetting;
alignmentSetting.spec = kCTParagraphStyleSpecifierAlignment;
alignmentSetting.valueSize = sizeof(CTTextAlignment);
alignmentSetting.value = &alignment;

CTParagraphStyleSetting settings[1] = {alignmentSetting};

size_t settingsCount = 1;
CTParagraphStyleRef paragraphRef = CTParagraphStyleCreate(settings, settingsCount);
NSDictionary *attributes = @{(__bridge id)kCTParagraphStyleAttributeName : (__bridge id)paragraphRef};
NSAttributedString *attributedString = [[NSAttributedString alloc] initWithString:@"Hello World" attributes:attributes];

回答by ejkujan

 NSMutableParagraphStyle *paragraphStyle = NSMutableParagraphStyle.new;
 paragraphStyle.alignment                = NSTextAlignmentCenter;

 NSAttributedString *attributedString   = 
[NSAttributedString.alloc initWithString:@"someText" 
                              attributes:
         @{NSParagraphStyleAttributeName:paragraphStyle}];

Swift 4.2

斯威夫特 4.2

let paragraphStyle: NSMutableParagraphStyle = NSMutableParagraphStyle()
    paragraphStyle.alignment = NSTextAlignment.center

    let attributedString = NSAttributedString(string: "someText", attributes: [NSAttributedString.Key.paragraphStyle : paragraphStyle])

回答by ZeMoon

I was searching for the same issue and was able to center align the text in a NSAttributedString this way:

我正在寻找同样的问题，并且能够以这种方式将 NSAttributedString 中的文本居中对齐：

NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc]init] ;
[paragraphStyle setAlignment:NSTextAlignmentCenter];

NSMutableAttributedString *attribString = [[NSMutableAttributedString alloc]initWithString:string];
[attribString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [string length])];

回答by Tommie C.

Swift 4.0+

斯威夫特 4.0+

let titleParagraphStyle = NSMutableParagraphStyle()
titleParagraphStyle.alignment = .center

let titleFont = UIFont.preferredFont(forTextStyle: UIFontTextStyle.headline)
let title = NSMutableAttributedString(string: "You Are Registered", 
    attributes: [.font: titleFont,    
    .foregroundColor: UIColor.red, 
    .paragraphStyle: titleParagraphStyle])

Swift 3.0+

斯威夫特 3.0+

let titleParagraphStyle = NSMutableParagraphStyle()
titleParagraphStyle.alignment = .center

let titleFont = UIFont.preferredFont(forTextStyle: UIFontTextStyle.headline)
let title = NSMutableAttributedString(string: "You Are Registered", 
    attributes: [NSFontAttributeName:titleFont,    
    NSForegroundColorAttributeName:UIColor.red, 
    NSParagraphStyleAttributeName: titleParagraphStyle])

(original answer below)

（以下原答案）

Swift 2.0+

斯威夫特 2.0+

let titleParagraphStyle = NSMutableParagraphStyle()
titleParagraphStyle.alignment = .Center

let titleFont = UIFont.preferredFontForTextStyle(UIFontTextStyleHeadline)
let title = NSMutableAttributedString(string: "You Are Registered",
    attributes:[NSFontAttributeName:titleFont,   
    NSForegroundColorAttributeName:UIColor.redColor(), 
    NSParagraphStyleAttributeName: titleParagraphStyle])

回答by George Maisuradze

Swift 4answer:

斯威夫特 4回答：

// Define paragraph style - you got to pass it along to NSAttributedString constructor
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.alignment = .center

// Define attributed string attributes
let attributes = [NSAttributedStringKey.paragraphStyle: paragraphStyle]

let attributedString = NSAttributedString(string:"Test", attributes: attributes)

回答by Ashwin G

In swift 4:

在快速 4：

    let paraStyle = NSMutableParagraphStyle.init()
    paraStyle.alignment = .left

    let str = "Test Message"
    let attribute = [NSAttributedStringKey.font: UIFont.boldSystemFont(ofSize: 12)]

    let attrMessage = NSMutableAttributedString(string: str, attributes: attribute)


    attrMessage.addAttribute(kCTParagraphStyleAttributeName as NSAttributedStringKey, value: paraStyle, range: NSMakeRange(0, str.count))

回答by mahendra

[averagRatioArray addObject:[NSString stringWithFormat:@"When you respond Yes to %@ the average response to    %@ was %0.02f",QString1,QString2,M1]];
[averagRatioArray addObject:[NSString stringWithFormat:@"When you respond No  to %@ the average response to    %@ was %0.02f",QString1,QString2,M0]];

UIFont *font2 = [UIFont fontWithName:@"Helvetica-Bold" size:15];
UIFont *font = [UIFont fontWithName:@"Helvetica-Bold" size:12];

NSMutableAttributedString *str=[[NSMutableAttributedString alloc] initWithString:[NSString stringWithFormat:@"When you respond Yes to %@ the average response to %@ was",QString1,QString2]];
[str addAttribute:NSFontAttributeName value:font range:NSMakeRange(0,[@"When you respond Yes to " length])];
[str addAttribute:NSFontAttributeName value:font2 range:NSMakeRange([@"When you respond Yes to " length],[QString1 length])];
[str addAttribute:NSFontAttributeName value:font range:NSMakeRange([QString1 length],[@" the average response to " length])];
[str addAttribute:NSFontAttributeName value:font2 range:NSMakeRange([@" the average response to " length],[QString2 length])];
[str addAttribute:NSFontAttributeName value:font range:NSMakeRange([QString2 length] ,[@" was" length])];
// [str addAttribute:NSFontAttributeName value:font2 range:NSMakeRange(49+[QString1 length]+[QString2 length] ,8)];
[averagRatioArray addObject:[NSString stringWithFormat:@"%@",str]];