对于那些迁移到iOS 8的人，这里有一个Swift的类扩展:

extension UILabel {

    func autoresize() {
        if let textNSString: NSString = self.text {
            let rect = textNSString.boundingRectWithSize(CGSizeMake(self.frame.size.width, CGFloat.max),
                options: NSStringDrawingOptions.UsesLineFragmentOrigin,
                attributes: [NSFontAttributeName: self.font],
                context: nil)
            self.frame = CGRectMake(self.frame.origin.x, self.frame.origin.y, self.frame.size.width, rect.height)
        }
    }

}

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    cellIdentifier = @"myCell";
    cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
    cell.myUILabel.lineBreakMode = UILineBreakModeWordWrap;        
    cell.myUILabel.numberOfLines = 0;
    cell.myUILabel.text = @"Some very very very very long text....."
    [cell.myUILabel.criterionDescriptionLabel sizeToFit];    
}

- (CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    UITableViewCell *cell = [self tableView:tableView cellForRowAtIndexPath:indexPath];
    CGFloat rowHeight = cell.myUILabel.frame.size.height + 10;

    return rowHeight;    
}

检查这个工作完美，没有添加单行代码。使用自动布局()

我根据你的要求做了一个demo给你从下面的链接下载，

自动调整UIView和UILabel的大小

循序渐进指南:-

步骤1:-设置约束为UIView

1)领先2)领先3)落后(主视图)

步骤2:—将constraint设置为Label 1

1)领先2)顶部3)尾随(从它的父视图)

步骤3:-将constraint设置为Label 2

1)领先2)尾随(从它的父视图)

第4步:-最棘手的给按钮的UILabel从UIView。

步骤5:-(可选)将constraint设置为UIButton

1)领先2)底部3)后拖4)固定高度(从主视图开始)

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根据文本。

以下是分类版本:

UILabel + AutoSize.h #进口

@interface UILabel (AutoSize)

- (void) autosizeForWidth: (int) width;

@end

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

要在Swift3中做到这一点，以下是代码:

 let labelSizeWithFixedWith = CGSize(width: 300, height: CGFloat.greatestFiniteMagnitude)
            let exactLabelsize = self.label.sizeThatFits(labelSizeWithFixedWith)
            self.label.frame = CGRect(origin: CGPoint(x: 20, y: 20), size: exactLabelsize)

UILabel *itemTitle = [[UILabel alloc] initWithFrame:CGRectMake(10.0f, 10,100, 200.0f)];
itemTitle.text = @"aseruy56uiytitfesh";
itemTitle.adjustsFontSizeToFitWidth = NO;
itemTitle.autoresizingMask = UIViewAutoresizingFlexibleWidth;
itemTitle.font = [UIFont boldSystemFontOfSize:18.0];
itemTitle.textColor = [UIColor blackColor];
itemTitle.shadowColor = [UIColor whiteColor];
itemTitle.shadowOffset = CGSizeMake(0, 1);
itemTitle.backgroundColor = [UIColor blueColor];
itemTitle.lineBreakMode = UILineBreakModeWordWrap;
itemTitle.numberOfLines = 0;
[itemTitle sizeToFit];
[self.view addSubview:itemTitle];

使用这里所有的属性都使用在标签上，并通过增加itemTitle中的文本来测试它。文本

itemTitle.text = @"diofgorigjveghnhkvjteinughntivugenvitugnvkejrfgnvkhv";

它会根据你的需要给出完美的答案