iOS 7 sizeWithAttributes：替换sizeWithFont：constrainedToSize

如何从新的iOS 7方法sizeWithAttributes返回多行文本CGSize？

我希望这产生与sizeWithFont：constrainedToSize相同的结果。

NSString *text = @"Lorem ipsum dolor sit amet, consectetur adipiscing elit. Phasellus eu urna quis lacus imperdiet scelerisque a nec neque. Mauris eget feugiat augue, vitae porttitor mi. Curabitur vitae sollicitudin augue. Donec id sapien eros. Proin consequat tellus in vehicula sagittis. Morbi sed felis a nibh hendrerit hendrerit. Lorem ipsum dolor sit."

CGSize textSize = [text sizeWithAttributes:@{ NSFontAttributeName : [UIFont fontWithName:@"HelveticaNeue-Light" size:16.0] }];

此方法仅产生一行文本的高度。

好吧，你可以试试这个：

NSDictionary *attributes = @{NSFontAttributeName: [UIFont fontWithName:@"HelveticaNeue" size:14]};
// NSString class method: boundingRectWithSize:options:attributes:context is
// available only on ios7.0 sdk.
CGRect rect = [textToMeasure boundingRectWithSize:CGSizeMake(width, CGFLOAT_MAX)
                                          options:NSStringDrawingUsesLineFragmentOrigin
                                       attributes:attributes
                                          context:nil];

这是我的方法：

    // Get a font to draw it in
UIFont *font = [UIFont boldSystemFontOfSize: 28];

CGRect textRect;
NSDictionary *attributes = @{NSFontAttributeName: font};

// How big is this string when drawn in this font?
textRect.size = [text sizeWithAttributes:attributes];

// Draw the string
[text drawInRect:textRect withAttributes:attributes];

Swift 2.3：

let attributes = [NSFontAttributeName:UIFont(name: "HelveticaNeue", size: 14)]
let rect = NSString(string: textToMeasure).boundingRectWithSize(
        CGSizeMake(width, CGFLOAT_MAX), 
        options: NSStringDrawingOptions.UsesLineFragmentOrigin, 
        attributes: attributes, context: nil)

斯威夫特4：

let attributes = [NSFontAttributeName:UIFont(name: "HelveticaNeue", size: 14)]
let rect = NSString(string: textToMeasure).boundingRect(
                    with: CGSize(width: width, height: CGFloat.greatestFiniteMagnitude),
                    options: NSStringDrawingOptions.usesLineFragmentOrigin,
                    attributes: attributes as [NSAttributedString.Key : Any], context: nil)

这是我处理这两种情况的方法，属于一个NSString类别。

- (CGSize) sizeWithFontOrAttributes:(UIFont *) font {
    if (IS_IOS7) {
        NSDictionary *fontWithAttributes = @{NSFontAttributeName:font};
        return [self sizeWithAttributes:fontWithAttributes];
    } else {
        return [self sizeWithFont:font];
    }
}

对于Xamarin.iOS：

UIFont descriptionLabelFont =  UIFont.SystemFontOfSize (11);
NSString textToMeasure = (NSString)DescriptionLabel.Text;

CGRect labelRect = textToMeasure.GetBoundingRect (
    new CGSize(this.Frame.Width, nfloat.MaxValue), 
    NSStringDrawingOptions.UsesLineFragmentOrigin, 
    new UIStringAttributes () { Font = descriptionLabelFont }, 
    new NSStringDrawingContext ()
);

如果您具有标签集的文本，字体，numberOfLines和宽度，则此方法将返回标签的大小：

myLabel.numberOfLines = 0;

CGSize size = [myLabel sizeThatFits:CGSizeMake(myLabel.frame.size.width, CGFLOAT_MAX)];`

或者，如果您正在查看UITextView，则始终可以使用以下NSLayoutManager方法：

CGSize textSize = [textView.layoutManager usedRectForTextContainer:textView.textContainer].size;

您还可以通过以下方式找到给定字体的行高：

UIFont *font;
CGFloat lineHeight = font.lineHeight;

[作为新用户，我不能在@testing的答案上发表评论，而是使他的答案（对于xamarin.ios）更加有用]

我们可以返回一个CGRect，并且只将height参数用于目标UIButton等的gui项。

    public CGRect GetRectForString(String strMeasure, int fontSize, nfloat guiItemWidth)
    {
        UIFont descriptionLabelFont =  UIFont.SystemFontOfSize (fontSize);
        NSString textToMeasure = (NSString)strMeasure;

        CGRect labelRect = textToMeasure.GetBoundingRect (
            new CGSize(guiItemWidth, nfloat.MaxValue), 
            NSStringDrawingOptions.UsesLineFragmentOrigin, 
            new UIStringAttributes () { Font = descriptionLabelFont }, 
            new NSStringDrawingContext ()
        );

        return labelRect;
    }

        header_Revision.Frame = new CGRect (5
                                            , verticalAdjust
                                            , View.Frame.Width-10
                                            , GetRectForString( header_Revision.Title(UIControlState.Normal)
                                                              , 18
                                                              , View.Frame.Width-10 ).Height
                                            );

CGSize stringsize = [lbl.text sizeWithAttributes:
                         @{NSFontAttributeName:[UIFont fontWithName:FontProximaNovaRegular size:12.0]}];


CGSize adjustedSize = CGSizeMake(ceilf(stringsize.width), ceilf(stringsize.height));

使用ceilf方法妥善管理