#import

@interface UILabel (BoundingRect)

//初始化的size,，size中高度或者寬度為0

-(CGRect)boundingRectWithInitSize:(CGSize)size;

@end

UILabel+BoundingRect.m

#import "UILabel+BoundingRect.h"

@implementation UILabel (BoundingRect)

-(CGRect)boundingRectWithInitSize:(CGSize)size

{

    self.lineBreakMode=NSLineBreakByWordWrapping;

    CGRect rect=[self.text boundingRectWithSize:size options:NSStringDrawingUsesLineFragmentOrigin attributes:[NSDictionary dictionaryWithObjectsAndKeys:self.font,NSFontAttributeName, nil] context:nil];

    return rect;

}

@end

- (CGSize)sizeWithAttributes:(NSDictionary *)attrs;

替代過(guò)時(shí)的iOS6中的- (CGSize)sizeWithFont:(UIFont *)font 方法

    // iOS7_API_根據(jù)文字 字?jǐn)?shù)動(dòng)態(tài)確定Label寬高

    
    // 設(shè)置Label的字體 HelveticaNeue  Courier
    UIFont *fnt = [UIFont fontWithName:@"HelveticaNeue" size:24.0f];
    _nameLabel.font = fnt;
    // 根據(jù)字體得到NSString的尺寸
    CGSize size = [_nameLabel.text sizeWithAttributes:[NSDictionary dictionaryWithObjectsAndKeys:fnt,NSFontAttributeName, nil]];
    // 名字的H
    CGFloat nameH = size.height;
    // 名字的W
    CGFloat nameW = size.width;
    _nameLabel.frame = CGRectMake(0, 0, nameW,nameH);

// 4,根據(jù)正文內(nèi)容多少,動(dòng)態(tài)確定正文content的frame
    
    // 寬度W
    CGFloat contentW = self.bounds.size.width - _content.frame.origin.x - kMargin;
    // label的字體 HelveticaNeue  Courier
    UIFont *fnt = [UIFont fontWithName:@"HelveticaNeue" size:18.0f];
    _content.font = fnt;
    _content.numberOfLines = 0;
    _content.lineBreakMode = NSLineBreakByWordWrapping;
    // iOS7中用以下方法替代過(guò)時(shí)的iOS6中的sizeWithFont:constrainedToSize:lineBreakMode:方法
    CGRect tmpRect = [_content.text boundingRectWithSize:CGSizeMake(contentW, 1000) options:NSStringDrawingUsesLineFragmentOrigin attributes:[NSDictionary dictionaryWithObjectsAndKeys:fnt,NSFontAttributeName, nil] context:nil];
    
    // 高度H
    CGFloat contentH = tmpRect.size.height;
    NSLog(@"調(diào)整后的顯示寬度:%f,顯示高度:%f"contentW,contentH);
    _content.frame = CGRectMake(0, 0, contentW,contentH);