UILabel垂直居中,自动收缩

时间:2013-07-31 13:40:15

标签: ios uilabel

这与其他所有内容略有不同“我如何将问题置于UILabel个问题中心......

我有UILabel,其中包含一些文字,我希望将文字垂直居中于UILabel。有什么大不了的,对吧?这是默认值。问题来了,因为我的文字是动态的,我打开了自动收缩。随着文本变大,字体大小缩小。你得到这种行为。

enter image description here

请注意,字体基线没有移动,我希望它移动,以便数字在UILabel's框架中垂直居中。

简单,对吗?我只记得viewDidLoad

中框架的原始中心
    self.workoutTimeCenter = _workoutTimeLabel.center;

然后我在更改文本后调用sizeToFit,对吗?

    [_workoutTimeLabel sizeToFit];
    _workoutTimeLabel.center = _workoutTimeCenter;

嗯,我想,sizeToFit完全应该做的事情,调整框架的大小,使文字合适而不缩小!

enter image description here

如何在尊重基线和自动收缩的同时将文本垂直居中UILabel? (注意, iOS5 以及后来的解决方案很好,我甚至可以处理 iOS6 及以后的解决方案。)

5 个答案:

答案 0 :(得分:93)

根据我的经验,您只需将-[UILabel baselineAdjustment]属性设置为UIBaselineAdjustmentAlignCenters即可达到您所描述的效果。

来自docs

  

baselineAdjustment

     

控制文本时如何调整文本基线   需要缩小以适应标签。

@property(nonatomic) UIBaselineAdjustment baselineAdjustment
     

讨论

     

如果adjustsFontSizeToFitWidth属性设置为YES,   此属性控制文本基线的行为   需要调整字体大小的情况。默认   此属性的值为UIBaselineAdjustment AlignBaselines 。这个   仅当numberOfLines属性设置为时,属性才有效   1

  

UIBaselineAdjustmentAlignCenters
  相对于其边界框的中心调整文本。

编辑:添加一个完整的视图控制器来演示:

@interface TSViewController : UIViewController
@end

@implementation TSViewController

- (void) addLabelWithFrame: (CGRect) f baselineAdjustment: (UIBaselineAdjustment) bla
{
    UILabel* label = [[UILabel alloc] initWithFrame: f];
    label.baselineAdjustment = bla;
    label.adjustsFontSizeToFitWidth = YES;
    label.font = [UIFont fontWithName: @"Courier" size: 200];
    label.text = @"00";
    label.textAlignment = NSTextAlignmentCenter;
    label.backgroundColor = [UIColor lightGrayColor];
    label.userInteractionEnabled = YES;
    [self.view addSubview: label];

    UIView* centerline = [[UIView alloc] initWithFrame: CGRectMake(f.origin.x, f.origin.y+(f.size.height/2.0), f.size.width, 1)];
    centerline.backgroundColor = [UIColor redColor];
    [self.view addSubview: centerline];

    UITapGestureRecognizer* tgr = [[UITapGestureRecognizer alloc] initWithTarget: self action: @selector(onTap:)];
    [label addGestureRecognizer: tgr];
}

- (void) viewDidLoad
{
    [super viewDidLoad];

    [self addLabelWithFrame: CGRectMake(0, 0, 320, 200)
         baselineAdjustment: UIBaselineAdjustmentAlignCenters];

    [self addLabelWithFrame: CGRectMake(0, 220, 320, 200)
         baselineAdjustment: UIBaselineAdjustmentAlignBaselines];
}

- (void) onTap: (UITapGestureRecognizer*) tgr
{
    UILabel* label = (UILabel*)tgr.view;
    NSString* t = [label.text stringByAppendingString: @":00"];
    label.text = t;
}

@end

答案 1 :(得分:2)

-(void)fitVerticallyToLabel:(UILabel *)lbl
{
    CGFloat fontSize = lbl.frame.size.width / lbl.text.length;
    [lbl setFont:[UIFont fontWithName:@"Helvetica-Bold" size:fontSize]];

    CGRect rect = lbl.frame;
    rect.origin.y += rect.size.height - fontSize;
    rect.size.height = fontSize;
    [lbl setFrame:rect];
}

使用方法:将文字设置为标签后调用此方法。

    label.text = @"text";
    [self fitVerticallyToLabel:label];

enter image description here enter image description here

注意:我从xib获取了UILabel。您也可以通过编程方式进行,在这种情况下,您必须设置其文本对齐方式NSTextAlignMentCenter

答案 2 :(得分:2)

在IB工作时,请务必将对齐基线设置为居中

enter image description here

注意:换行不能自动换行,所以它不能工作多行(很好将换行设置为截断尾部)

答案 3 :(得分:1)

尝试实现此逻辑:

-(void)adjustLabel1Text1:(NSString *)text1 
{
    UILabel *lbl_first = [UIFont fontWithName:@"Helvetica" size:12];



    text1 = [text1 stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];


    float hedingLblHeight = [self calculateHeightOfTextFromWidth:text1 : [UIFont fontWithName:@"Helvetica" size:12] :118 :UILineBreakModeWordWrap];

    lbl_first.text=text1;


    [lbl_first setFrame:CGRectMake(lbl_first.frame.origin.x, lbl_first.frame.origin.y, 118, hedingLblHeight)];
    lbl_first.lineBreakMode = UILineBreakModeWordWrap;
    lbl_first.numberOfLines = 0;
    [lbl_first sizeToFit];




//////////Adjust the lable or any UIControl below this label accordingly.

    float endResultHeight=[self calculateHeightOfTextFromWidth:text2 : [UIFont fontWithName:@"Helvetica" size:15] :299 :UILineBreakModeWordWrap];

    if(hedingLblHeight>secondImgTitleHeight)
    {
    [lbl_endResult setFrame:CGRectMake(lbl_endResult.frame.origin.x, lbl_first.frame.origin.y+lbl_first.frame.size.height+5, 299, endResultHeight)];
    }
    else
    {
        [lbl_endResult setFrame:CGRectMake(lbl_endResult.frame.origin.x, lbl_first.frame.origin.y+lbl_first.frame.size.height+5, 299, endResultHeight)];

    }

    lbl_endResult.lineBreakMode=UILineBreakModeWordWrap;
    lbl_endResult.numberOfLines = 0;
    [lbl_endResult sizeToFit];



}

-(float) calculateHeightOfTextFromWidth:(NSString*)text : (UIFont*) withFont:(float)width :(UILineBreakMode)lineBreakMode
{

    CGSize suggestedSize = [text sizeWithFont:withFont constrainedToSize:CGSizeMake(width, FLT_MAX) lineBreakMode:lineBreakMode];

    return suggestedSize.height;
}

它给了我很多帮助。希望它适合你。

答案 4 :(得分:-4)

尝试

yourLabel.textAlignment = UITextAlignmentCenter;