根据Text动态获取UILabel的高度为iOS 7.0和iOS 6.1返回不同的值

Question

我正在使用此方法动态获取UILabel的高度:

+(CGSize) GetSizeOfLabelForGivenText:(UILabel*)label Font:(UIFont*)fontForLabel Size:  (CGSize)LabelSize{
    label.numberOfLines = 0;
    CGSize labelSize = [label.text sizeWithFont:fontForLabel constrainedToSize:LabelSize lineBreakMode:NSLineBreakByCharWrapping];
    return (labelSize);
}

使用此解决方案,如果我的代码在iOS 8下运行,我将获得UILabel的确切大小,但如果我在iOS7上运行我的应用程序,则返回不同的值.

Answer 1

您必须动态设置框架,如下所示:

let constrainedSize = CGSize(width: self.titleLable.frame.size.width, height:9999)

let attributesDictionary = [NSAttributedString.Key.font: UIFont.init(name: "HelveticaNeue", size: 11.0)]

let string = NSAttributedString.init(string: "textToShow", attributes: attributesDictionary as [NSAttributedString.Key : Any])

var requiredHeight = string.boundingRect(with: constrainedSize, options: .usesLineFragmentOrigin, context: nil)


if (requiredHeight.size.width > self.titleLable.frame.size.width) {
    requiredHeight = CGRect(x: 0, y: 0, width: self.titleLable.frame.size.width, height: requiredHeight.size.height)
}
var newFrame = self.titleLable.frame
newFrame.size.height = requiredHeight.size.height
self.titleLable.frame = newFrame

Answer 2

这是宽度和高度的完整解决方案.把它们放在AppDelegate中:

+(void)fixHeightOfThisLabel:(UILabel *)aLabel
{
    aLabel.frame = CGRectMake(aLabel.frame.origin.x,
                              aLabel.frame.origin.y,
                              aLabel.frame.size.width,
                              [AppDelegate heightOfTextForString:aLabel.text
                                                         andFont:aLabel.font
                                                         maxSize:CGSizeMake(aLabel.frame.size.width, MAXFLOAT)]);
}

+(CGFloat)heightOfTextForString:(NSString *)aString andFont:(UIFont *)aFont maxSize:(CGSize)aSize
{
    // iOS7
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7.0)
    {
        CGSize sizeOfText = [aString boundingRectWithSize: aSize
                                                  options: (NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading)
                                               attributes: [NSDictionary dictionaryWithObject:aFont
                                                                                       forKey:NSFontAttributeName]
                                                  context: nil].size;

        return ceilf(sizeOfText.height);
    }

    // iOS6
    CGSize textSize = [aString sizeWithFont:aFont
                          constrainedToSize:aSize
                              lineBreakMode:NSLineBreakByWordWrapping];
    return ceilf(textSize.height;
}

+(void)fixWidthOfThisLabel:(UILabel *)aLabel
{
    aLabel.frame = CGRectMake(aLabel.frame.origin.x,
                              aLabel.frame.origin.y,
                                [AppDelegate widthOfTextForString:aLabel.text
                                                          andFont:aLabel.font
                                                          maxSize:CGSizeMake(MAXFLOAT, aLabel.frame.size.height)],
                              aLabel.frame.size.height);
}

+(CGFloat)widthOfTextForString:(NSString *)aString andFont:(UIFont *)aFont maxSize:(CGSize)aSize
{
    // iOS7
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 7.0)
    {
        CGSize sizeOfText = [aString boundingRectWithSize: aSize
                                                  options: (NSStringDrawingUsesLineFragmentOrigin|NSStringDrawingUsesFontLeading)
                                               attributes: [NSDictionary dictionaryWithObject:aFont
                                                                                       forKey:NSFontAttributeName]
                                                  context: nil].size;

        return ceilf(sizeOfText.width);
    }

    // iOS6
    CGSize textSize = [aString sizeWithFont:aFont
                          constrainedToSize:aSize
                              lineBreakMode:NSLineBreakByWordWrapping];
    return ceilf(textSize.width);
}

然后使用它,设置标签的文本:

label.numberOfLines = 0;
label.text = @"Everyone loves Stack OverFlow";

并致电:

[AppDelegate fixHeightOfThisLabel:label];

注意:标签的numberOfLines必须设置为0.希望有所帮助.