根据文字调整UILabel高度

Question

考虑我在UILabel(动态文本的长行)中有以下文本:

由于外星军队的数量远远超过了团队,因此玩家必须利用后世界末日的世界,例如在垃圾箱,支柱,汽车,瓦砾和其他物体后面寻找掩护.

我想调整UILabel's高度,以便文本可以适应.我正在使用以下属性UILabel来使文本包装.

myUILabel.lineBreakMode = UILineBreakModeWordWrap;
myUILabel.numberOfLines = 0;

如果我没有朝着正确的方向前进,请告诉我.谢谢.

Answer 1

sizeWithFont constrainedToSize:lineBreakMode:是使用的方法.以下是如何使用它的示例:

//Calculate the expected size based on the font and linebreak mode of your label
// FLT_MAX here simply means no constraint in height
CGSize maximumLabelSize = CGSizeMake(296, FLT_MAX);

CGSize expectedLabelSize = [yourString sizeWithFont:yourLabel.font constrainedToSize:maximumLabelSize lineBreakMode:yourLabel.lineBreakMode];   

//adjust the label the the new height.
CGRect newFrame = yourLabel.frame;
newFrame.size.height = expectedLabelSize.height;
yourLabel.frame = newFrame;

Answer 2

你正朝着正确的方向前进.你需要做的就是:

myUILabel.numberOfLines = 0;
myUILabel.text = @"Enter large amount of text here";
[myUILabel sizeToFit];

Answer 3

在iOS 6中,Apple为UILabel添加了一个属性,极大地简化了标签的动态垂直大小调整:preferredMaxLayoutWidth.

将此属性与lineBreakMode = NSLineBreakByWordWrapping和sizeToFit方法结合使用,可以轻松地将UILabel实例的大小调整为适应整个文本的高度.

来自iOS文档的引用:

preferredMaxLayoutWidth 多行标签的首选最大宽度(以磅为单位).

讨论 当应用布局约束时,此属性会影响标签的大小.在布局期间,如果文本超出此属性指定的宽度,则附加文本将流向一个或多个新行,从而增加标签的高度.

一个样品:

...
UILabel *status = [[UILabel alloc] init];
status.lineBreakMode = NSLineBreakByWordWrapping;
status.numberOfLines = 5; // limits to 5 lines; use 0 for unlimited.

[self addSubview:status]; // self here is the parent view

status.preferredMaxLayoutWidth = self.frame.size.width; // assumes the parent view has its frame already set.

status.text = @"Some quite lengthy message may go here…";
[status sizeToFit];
[status setNeedsDisplay];
...

Answer 4

而是以编程方式执行此操作,您可以在设计时在Storyboard/XIB中执行此操作.

• 在属性检查器中将UIlabel的行数属性设置为0.
• 然后根据要求设置宽度约束/(或)前导和尾随约束.
• 然后用最小值设置高度约束.最后选择您添加的高度约束,并在尺寸检查器中选择属性检查器旁边的高度约束,将高度约束的关系从等于 - 大于.更改.

Answer 5

无需添加单行代码即可完美检查此工作.(使用Autolayout)

我根据你的要求为你做了一个演示.从以下链接下载,

自动化UIView和UILabel

分步指南: -

第1步: -将约束设置为UIView

1)领先2)Top 3)尾随(来自主视图)

第2步: -将约束设置为标签1

1)领先2)前3)尾随(从它的超级视图)

第3步: -将约束设置为标签2

1)领先2)尾随(从它的超级视图)

第4步: - 最棘手的是从UIView向UILabel提供帮助.

步骤5: -(可选)将约束设置为UIButton

1)领先2)底部3)尾随4)固定高度(来自主视图)

输出: -

注意: -确保在Label属性中设置了Number of lines = 0.

我希望这个信息足以理解Autoresize UIView根据UILabel的高度和Autoresize UILabel根据文字.

Answer 6

谢谢大家的帮助,这是我尝试的代码,这对我有用

   UILabel *instructions = [[UILabel alloc]initWithFrame:CGRectMake(10, 225, 300, 180)];
   NSString *text = @"First take clear picture and then try to zoom in to fit the ";
   instructions.text = text;
   instructions.textAlignment = UITextAlignmentCenter;
   instructions.lineBreakMode = NSLineBreakByWordWrapping;
   [instructions setTextColor:[UIColor grayColor]];

   CGSize expectedLabelSize = [text sizeWithFont:instructions.font 
                                constrainedToSize:instructions.frame.size
                                    lineBreakMode:UILineBreakModeWordWrap];

    CGRect newFrame = instructions.frame;
    newFrame.size.height = expectedLabelSize.height;
    instructions.frame = newFrame;
    instructions.numberOfLines = 0;
    [instructions sizeToFit];
    [self addSubview:instructions];

Answer 7

解决iOS7之前和iOS7以上的问题

//
//  UILabel+DynamicHeight.m
//  For StackOverFlow
//
//  Created by Vijay on 24/02/14.
//  Copyright (c) 2014 http://Vijay-Apple-Dev.blogspot.com. All rights reserved.
//

#import <UIKit/UIKit.h>

#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(v)  ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] != NSOrderedAscending)

#define SYSTEM_VERSION_LESS_THAN(v)                 ([[[UIDevice currentDevice] systemVersion] compare:v options:NSNumericSearch] == NSOrderedAscending)

#define iOS7_0 @"7.0"

@interface UILabel (DynamicHeight)

/*====================================================================*/

/* Calculate the size,bounds,frame of the Multi line Label */

/*====================================================================*/
/**
 *  Returns the size of the Label
 *
 *  @param aLabel To be used to calculte the height
 *
 *  @return size of the Label
 */

-(CGSize)sizeOfMultiLineLabel;

@end


//
//  UILabel+DynamicHeight.m
//  For StackOverFlow
//
//  Created by Vijay on 24/02/14.
//  Copyright (c) 2014 http://Vijay-Apple-Dev.blogspot.com. All rights reserved.
//

#import "UILabel+DynamicHeight.h"

@implementation UILabel (DynamicHeight)
/*====================================================================*/

/* Calculate the size,bounds,frame of the Multi line Label */

/*====================================================================*/
/**
 *  Returns the size of the Label
 *
 *  @param aLabel To be used to calculte the height
 *
 *  @return size of the Label
 */
-(CGSize)sizeOfMultiLineLabel{

    NSAssert(self, @"UILabel was nil");

    //Label text
    NSString *aLabelTextString = [self text];

    //Label font
    UIFont *aLabelFont = [self font];

    //Width of the Label
    CGFloat aLabelSizeWidth = self.frame.size.width;


    if (SYSTEM_VERSION_LESS_THAN(iOS7_0)) {
        //version < 7.0

        return [aLabelTextString sizeWithFont:aLabelFont
                            constrainedToSize:CGSizeMake(aLabelSizeWidth, MAXFLOAT)
                                lineBreakMode:NSLineBreakByWordWrapping];
    }
    else if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(iOS7_0)) {
        //version >= 7.0

        //Return the calculated size of the Label
        return [aLabelTextString boundingRectWithSize:CGSizeMake(aLabelSizeWidth, MAXFLOAT)
                                              options:NSStringDrawingUsesLineFragmentOrigin
                                           attributes:@{
                                                        NSFontAttributeName : aLabelFont
                                                        }
                                              context:nil].size;

    }

    return [self bounds].size;

}

@end

Answer 8

由于不推荐使用sizeWithFont,我使用这个.

这个获得标签特定的属性.

-(CGFloat)heightForLabel:(UILabel *)label withText:(NSString *)text{

    NSAttributedString *attributedText = [[NSAttributedString alloc] initWithString:text attributes:@{NSFontAttributeName:label.font}];
    CGRect rect = [attributedText boundingRectWithSize:(CGSize){label.frame.size.width, CGFLOAT_MAX}
                                           options:NSStringDrawingUsesLineFragmentOrigin
                                           context:nil];

    return ceil(rect.size.height);
}

Answer 9

您可以TableViewController's (UITableViewCell *)tableView:cellForRowAtIndexPath 通过以下方式实现方法(例如):

#define CELL_LABEL_TAG 1

- (UITableViewCell *)tableView:(UITableView *)tableView  cellForRowAtIndexPath:(NSIndexPath *)indexPath {
    NSString *text = @"my long text";

    static NSString *MyIdentifier = @"MyIdentifier";
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:MyIdentifier];
    if (cell == nil) {
        cell = [[[UITableViewCell alloc] initWithFrame:CGRectZero  reuseIdentifier:identifier] autorelease];
    }

    CGFloat width = [UIScreen mainScreen].bounds.size.width - 50;
    CGFloat height = [self textHeight:text] + 10;
    CGRect frame = CGRectMake(10.0f, 10.0f, width, height);

    UILabel *cellLabel = [[UILabel alloc] initWithFrame:frame];
    cellLabel.tag = CELL_LABEL_TAG;
    cellLabel.textColor = [UIColor blackColor];
    cellLabel.backgroundColor = [UIColor clearColor];
    cellLabel.textAlignment = UITextAlignmentLeft;
    cellLabel.font = [UIFont systemFontOfSize:12.0f];
    [cell.contentView addSubview:cellLabel];
    [cellLabel release];

    return cell;
}

UILabel *label = (UILabel *)[cell viewWithTag:CELL_LABEL_TAG];
label.text = text;
label.numberOfLines = 0;
[label sizeToFit];
return cell;

还可以使用NSString的sizeWithFont:constrainedToSize:lineBreakMode:方法来计算文本的高度.

Answer 10

这是一个类别版本:

UILabel + AutoSize.h #import

@interface UILabel (AutoSize)

- (void) autosizeForWidth: (int) width;

@end

的UILabel + AutoSize.m

#import "UILabel+AutoSize.h"

@implementation UILabel (AutoSize)

- (void) autosizeForWidth: (int) width {
    self.lineBreakMode = UILineBreakModeWordWrap;
    self.numberOfLines = 0;
    CGSize maximumLabelSize = CGSizeMake(width, FLT_MAX);
    CGSize expectedLabelSize = [self.text sizeWithFont:self.font constrainedToSize:maximumLabelSize lineBreakMode:self.lineBreakMode];
    CGRect newFrame = self.frame;
    newFrame.size.height = expectedLabelSize.height;
    self.frame = newFrame;
}

@end

Answer 11

基于扩展的UILabel这个答案对于斯威夫特4及以上

extension UILabel {

    func retrieveTextHeight () -> CGFloat {
        let attributedText = NSAttributedString(string: self.text!, attributes: [NSFontAttributeName:self.font])

        let rect = attributedText.boundingRect(with: CGSize(width: self.frame.size.width, height: CGFloat.greatestFiniteMagnitude), options: .usesLineFragmentOrigin, context: nil)

        return ceil(rect.size.height)
    }

}

可以像这样使用：

self.labelHeightConstraint.constant = self.label.retrieveTextHeight()

Answer 12

我计算 UILabel 动态高度的方法。

    let width = ... //< width of this label 
    let text = ... //< display content

    label.numberOfLines = 0
    label.lineBreakMode = .byWordWrapping
    label.preferredMaxLayoutWidth = width

    // Font of this label.
    //label.font = UIFont.systemFont(ofSize: 17.0)
    // Compute intrinsicContentSize based on font, and preferredMaxLayoutWidth
    label.invalidateIntrinsicContentSize() 
    // Destination height
    let height = label.intrinsicContentSize.height

包装功能：

func computeHeight(text: String, width: CGFloat) -> CGFloat {
    // A dummy label in order to compute dynamic height.
    let label = UILabel()

    label.numberOfLines = 0
    label.lineBreakMode = .byWordWrapping
    label.font = UIFont.systemFont(ofSize: 17.0)

    label.preferredMaxLayoutWidth = width
    label.text = text
    label.invalidateIntrinsicContentSize()

    let height = label.intrinsicContentSize.height
    return height
}