// 要计算的文本内容

    NSString *testString = @"刘成利，软件工程专业毕业，iOS开发者，目前工作于北京，在证券金融领域从事iOS App开发，由于工作有闲暇时间，所以开始写博客，分享自己浅薄的iOS相关开发经验，希望任何人士多多指正指点或者批评教育。";

    UILabel *labeliOS7        = [[UILabel alloc]init];

    labeliOS7.text            = testString;

    labeliOS7.font            = [UIFont systemFontOfSize:];

    labeliOS7.backgroundColor = [UIColor lightGrayColor];

    labeliOS7.numberOfLines   = ;

    // 计算高度

    /*

     参数说明：boundingRectWithSize:后面跟随宽度和高度

     */

    CGSize titleSize = [testString boundingRectWithSize:CGSizeMake(, MAXFLOAT) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName:[UIFont systemFontOfSize:]} context:nil].size;

    labeliOS7.frame  = CGRectMake(, , , titleSize.height);

    [self.view addSubview:labeliOS7];

//

//  NSString+LabelWidthAndHeight.h

//  ZiPeiYi

//

//  Created by YouXianMing on 15/12/9.

//  Copyright © 2015年 YouXianMing. All rights reserved.

//

#import <Foundation/Foundation.h>

#import <UIKit/UIKit.h>

@interface NSString (LabelWidthAndHeight)

/**

 *  Get the string's height with the fixed width.

 *

 *  @param attribute String's attribute, eg. attribute = @{NSFontAttributeName: [UIFont systemFontOfSize:18.f]}

 *  @param width     Fixed width.

 *

 *  @return String's height.

 */

- (CGFloat)heightWithStringAttribute:(NSDictionary <NSString *, id> *)attribute fixedWidth:(CGFloat)width;

/**

 *  Get the string's width.

 *

 *  @param attribute String's attribute, eg. attribute = @{NSFontAttributeName: [UIFont systemFontOfSize:18.f]}

 *

 *  @return String's width.

 */

- (CGFloat)widthWithStringAttribute:(NSDictionary <NSString *, id> *)attribute;

/**

 *  Get a line of text height.

 *

 *  @param attribute String's attribute, eg. attribute = @{NSFontAttributeName: [UIFont systemFontOfSize:18.f]}

 *

 *  @return String's width.

 */

+ (CGFloat)aLineOfTextHeightWithStringAttribute:(NSDictionary <NSString *, id> *)attribute;

@end

//

//  NSString+LabelWidthAndHeight.m

//  ZiPeiYi

//

//  Created by YouXianMing on 15/12/9.

//  Copyright © 2015年 YouXianMing. All rights reserved.

//

#import "NSString+LabelWidthAndHeight.h"

@implementation NSString (LabelWidthAndHeight)

- (CGFloat)heightWithStringAttribute:(NSDictionary <NSString *, id> *)attribute fixedWidth:(CGFloat)width {

    NSParameterAssert(attribute);

    CGFloat height = ;

    if (self.length) {

        CGRect rect = [self boundingRectWithSize:CGSizeMake(width, MAXFLOAT)

                                         options:NSStringDrawingTruncatesLastVisibleLine |NSStringDrawingUsesLineFragmentOrigin |

                       NSStringDrawingUsesFontLeading

                                      attributes:attribute

                                         context:nil];

        height = rect.size.height;

    }

    return height;

}

- (CGFloat)widthWithStringAttribute:(NSDictionary <NSString *, id> *)attribute {

    NSParameterAssert(attribute);

    CGFloat width = ;

    if (self.length) {

        CGRect rect = [self boundingRectWithSize:CGSizeMake(MAXFLOAT, )

                                         options:NSStringDrawingTruncatesLastVisibleLine |NSStringDrawingUsesLineFragmentOrigin |

                       NSStringDrawingUsesFontLeading

                                      attributes:attribute

                                         context:nil];

        width = rect.size.width;

    }

    return width;

}

+ (CGFloat)aLineOfTextHeightWithStringAttribute:(NSDictionary <NSString *, id> *)attribute {

    CGFloat height = ;

    CGRect rect    = [@"One" boundingRectWithSize:CGSizeMake(, MAXFLOAT)

                                          options:NSStringDrawingTruncatesLastVisibleLine |NSStringDrawingUsesLineFragmentOrigin |

                      NSStringDrawingUsesFontLeading

                                       attributes:attribute

                                          context:nil];

    height = rect.size.height;

    return height;

}

@end