iOS开发之功能模块--计算高度Demo探究手稿

本篇记录关于计算文本高度和Label高度的代码，以备后期再探究：

首先是YouXianMing老师的工具类别：

NSString+LabelWidthAndHeight.h

//
//  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)oneLineOfTextHeightWithStringAttribute:(NSDictionary <NSString *, id> *)attribute;


- (CGSize)getSizeWithFont:(UIFont *)font constrainedToSize:(CGSize)size;

@end

NSString+LabelWidthAndHeight.m

//
//  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 = 0;
    
    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 = 0;
    
    if (self.length) {
        
        CGRect rect = [self boundingRectWithSize:CGSizeMake(MAXFLOAT, 0)
                                         options:NSStringDrawingTruncatesLastVisibleLine |NSStringDrawingUsesLineFragmentOrigin |
                       NSStringDrawingUsesFontLeading
                                      attributes:attribute
                                         context:nil];
        width = rect.size.width;
    }
    
    return width;
}

+ (CGFloat)oneLineOfTextHeightWithStringAttribute:(NSDictionary <NSString *, id> *)attribute {
    
    CGFloat height = 0;
    CGRect rect    = [@"One" boundingRectWithSize:CGSizeMake(200, MAXFLOAT)
                                          options:NSStringDrawingTruncatesLastVisibleLine |NSStringDrawingUsesLineFragmentOrigin |
                      NSStringDrawingUsesFontLeading
                                       attributes:attribute
                                          context:nil];
    height = rect.size.height;
    return height;
}

- (CGSize)getSizeWithFont:(UIFont *)font constrainedToSize:(CGSize)size{
    NSParameterAssert(font);
    CGSize resultSize = CGSizeZero;
    if (self.length <= 0) {
        return resultSize;
    }
    resultSize = [self boundingRectWithSize:size
                                    options:(NSStringDrawingUsesFontLeading | NSStringDrawingUsesLineFragmentOrigin)
                                 attributes:@{NSFontAttributeName: font}
                                    context:nil].size;
    resultSize = CGSizeMake(MIN(size.width, ceilf(resultSize.width)), MIN(size.height, ceilf(resultSize.height)));
    return resultSize;
}

@end

然后是我的探究代码，见笑：

#import "ViewController.h"
#import "NSString+LabelWidthAndHeight.h"

#define Content @"字体ad大家\n好，我叫帅哥，你们\n\n\n\n\n\n字体ad大家\n好，我叫帅哥，你们都是好人你们都是好人你们都是好人你们都是好人\n都是不哦联赛结案件\n发；个；案发金额了\n国家；姐夫都\n\n\n\n\n\n是不哦联赛结案件\n发；个；案发金额了\n国家；姐夫"


#define LabelFont [UIFont systemFontOfSize:14]
@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    //    CGFloat labelHeigh = [Content heightWithStringAttribute:attDic fixedWidth:labelWidth];
//    NSDictionary *attDic = @{NSFontAttributeName : [UIFont systemFontOfSize:14]};
    CGFloat labelWidth = 200;
    CGSize maxSize = CGSizeMake(labelWidth, MAXFLOAT);
    CGFloat labelHeigh = [Content getSizeWithFont:LabelFont constrainedToSize:maxSize].height;
    CGFloat aHeigh = labelHeigh;
    
    
    
    
//    NSLog(@"计算出来的高度是：%lf",labelHeigh);
    UILabel *label = [UILabel new];
    label.font = LabelFont;
    label.frame = CGRectMake(0, 200, labelWidth , 3);
    label.numberOfLines = 0;
    label.lineBreakMode = NSLineBreakByCharWrapping;
    label.text = Content;
    label.backgroundColor = [UIColor cyanColor];
    
    [label sizeToFit];
//    NSLog(@"计算出来Label的高度是：%lf",label.frame.size.height);
//    NSLog(@"计算出来Label的宽度是：%lf",label.frame.size.width);
    
    label.frame = CGRectMake(0, 200, label.frame.size.width, label.frame.size.height);
    [self.view addSubview:label];
    
    NSLog(@"计算高度的差值：%lf",label.frame.size.height - aHeigh);
    
//    CGSize size = CGSizeMake(200, 3);
//    UILabel *label = [UILabel new];
//    label.font = [UIFont systemFontOfSize:18];
//    label.numberOfLines = 0;
//    label.lineBreakMode = NSLineBreakByCharWrapping;
//    label.text = Content;
//    CGRect labelFrame = label.frame;
//    labelFrame.size = size;
//    label.frame = labelFrame;
//    [label sizeToFit];
//    labelFrame = label.frame;
//    label.backgroundColor = [UIColor cyanColor];
////    resultSize = labelFrame.size;
//    NSLog(@"计算出来Label的高度是：%lf",label.frame.size.height);
//    NSLog(@"计算出来Label的宽度是：%lf",label.frame.size.width);
//    [self.view addSubview:label];
    
    
    UILabel *label2 = [UILabel new];
    label2.frame = CGRectMake(0, 0, labelWidth, aHeigh);
    label2.font = LabelFont;
    label2.text = Content;
    label2.lineBreakMode = NSLineBreakByCharWrapping;
    label2.numberOfLines = 0;
    label2.backgroundColor = [UIColor redColor];
    [self.view addSubview:label2];
    
    NSLog(@"屏幕的宽度%lf",[UIScreen mainScreen].bounds.size.width);
    
    
    
}


@end