NSAttributedString add text alignment

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

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

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];
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最佳答案

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

For example:

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


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

Swift 4.2

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


let attributedString = NSAttributedString(string: "someText", attributes: [NSAttributedString.Key.paragraphStyle : paragraphStyle])
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I was searching for the same issue and was able to center align the text in a NSAttributedString this way:

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


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

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)

Swift 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])
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Swift 4 answer:

// 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)
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In swift 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))
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Xamarin.iOS

NSMutableParagraphStyle paragraphStyle = new NSMutableParagraphStyle();
paragraphStyle.HyphenationFactor = 1.0f;
var hyphenAttribute = new UIStringAttributes();
hyphenAttribute.ParagraphStyle = paragraphStyle;
var attributedString = new NSAttributedString(str: name, attributes: hyphenAttribute);
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If you use UILabel, just use label.textAlignment = .center instead


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