UILabel自适配text文本的宽度

#import "ViewController.h"

@interface ViewController ()

@property (nonatomic, strong) UILabel *fontLabel;

@property (nonatomic, strong) UITextField *textField;

@end

@implementation ViewController

- (void)viewDidLoad {

[super viewDidLoad];

_textField = [[UITextField alloc]initWithFrame:CGRectMake(10, 50, 320, 40)];

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(changeTextField) name:UITextFieldTextDidChangeNotification object:nil];

_textField.backgroundColor = [UIColor purpleColor];

_textField.keyboardType = UIKeyboardTypeEmailAddress;

_textField.returnKeyType = UIReturnKeyDone;

_textField.delegate = self;

[self.view addSubview:_textField];

_fontLabel = [[UILabel alloc]initWithFrame:CGRectMake(10,140,320,40)];

_fontLabel.backgroundColor = [UIColor blueColor];

NSString *fontString = @"明月几时有，把酒问酒吧";

CGSize labelSize = CGSizeMake(320,2000);

CGSize fontStringSize = [fontString boundingRectWithSize:labelSize options:NSStringDrawingUsesLineFragmentOrigin attributes:@{NSFontAttributeName : [UIFont systemFontOfSize:13]} context:nil].size;

_fontLabel.frame = CGRectMake(10, 260, fontStringSize.width, 40);

_fontLabel.text = fontString;

//    [_fontLabel sizeToFit];

_fontLabel.textAlignment = NSTextAlignmentRight;

[self.view addSubview:_fontLabel];

UIButton *click = [[UIButton alloc]initWithFrame:CGRectMake(50, 100, 140, 40)];

[click setTitle:@"点击我吧" forState:UIControlStateNormal];

click.backgroundColor = [UIColor redColor];

[click addTarget:self action:@selector(touchMe) forControlEvents:UIControlEventTouchUpInside];

[self.view addSubview:click];

}

- (void)touchMe {

[_fontLabel sizeToFit];

}

- (void)changeTextField {

_fontLabel.text = self.textField.text;

//    [_fontLabel sizeToFit];

}