IOS7 根据字符串求尺寸

来源：互联网发布：js prop checked 编辑：程序博客网时间：2024/05/17 23:42

原文：http://blog.csdn.net/itpeng523/article/details/23700385

一、先用xcode创建一个单视图工程

主界面为

为NSString写个求size的分类

#import "NSString+Size.h"

@implementation NSString (Size)

- (CGSize)textSizeWithFont:(UIFont *)font constrainedToSize:(CGSize)size lineBreakMode:(NSLineBreakMode)lineBreakMode

{

CGSize textSize;

if (CGSizeEqualToSize(size, CGSizeZero))

{

// NSDictionary *attributes = @{NSFontAttributeName:font}

NSDictionary *attributes = [NSDictionarydictionaryWithObject:font forKey:NSFontAttributeName];

// textSize = [self sizeWithAttributes:attributes];

// textSize = []

textSize = [self sizeWithAttributes:attributes];

}

else

{

NSStringDrawingOptions option =NSStringDrawingTruncatesLastVisibleLine |NSStringDrawingUsesLineFragmentOrigin |NSStringDrawingUsesFontLeading;

//NSStringDrawingTruncatesLastVisibleLine如果文本内容超出指定的矩形限制，文本将被截去并在最后一个字符后加上省略号。如果指定了NSStringDrawingUsesLineFragmentOrigin选项，则该选项被忽略NSStringDrawingUsesFontLeading计算行高时使用行间距。（译者注：字体大小+行间距=行高）

NSDictionary *attributes = [NSDictionarydictionaryWithObject:font forKey:NSFontAttributeName];

CGRect rect = [self boundingRectWithSize:size

options:option

attributes:attributes

context:nil];

textSize = rect.size;

}

return textSize;

}

@end

主代码实现：

ViewController.h

#import <UIKit/UIKit.h>

#import "NSString+Size.h"

@interface ViewController : UIViewController

@property (weak, nonatomic) IBOutlet UITextField *mTextField;

@property (weak, nonatomic) IBOutlet UILabel *outTextField;

- (IBAction)switchKeboardInput:(id)sender;

+(CGSize)sizeOfContent:(NSString *)name;

@end

ViewController.m文件

#import "ViewController.h"

@interface ViewController ()

@end

@implementation ViewController

- (void)viewDidLoad

{

[super viewDidLoad];

// Do any additional setup after loading the view, typically from a nib.

}

- (void)viewDidAppear:(BOOL)animated

{

[super viewDidAppear:animated];

[[NSNotificationCenter defaultCenter]addObserver:selfselector:@selector(changeKeyBoard:)name:UIKeyboardWillChangeFrameNotification object:nil]; //键盘改变事件

}

- (void)viewWillDisappear:(BOOL)animated

{

}

-(void)changeKeyBoard:(NSNotification *)aNotifacation

{

//求字符串的长度

CGSize textSize = [ViewController sizeOfContent:_mTextField.text];

NSString *str = [NSString stringWithFormat:@"宽度为%.2f,高度为%.2f",textSize.width,textSize.height];

_outTextField.text = str;

}

+ (CGSize)sizeOfContent:(NSString *)name

{

if (name.length == 0) {

return CGSizeMake(0, 0);

}

NSMutableString *string = [NSMutableStringstringWithString:name];

return [string textSizeWithFont:[UIFont systemFontOfSize:15]constrainedToSize:CGSizeMake(100, 1000)lineBreakMode:NSLineBreakByWordWrapping]; //一行宽度最大为 100 高度1000

}

- (IBAction)switchKeboardInput:(id)sender

{

[_mTextField resignFirstResponder];

}

@end

运行结果：

0 0