精通ios开发第六版,第一章,文章中的例子及习题.

 1 #import "ViewController.h"
 2 
 3 @interface ViewController ()
 4 
 5 @end
 6 
 7 @implementation ViewController
 8 
 9 
10 - (IBAction)buttonPressed:(UIButton *)sender {
11     //取出按钮的title
12     NSString *title = [sender titleForState:UIControlStateNormal];
13     
14     //用取出的title格式化为字符串,并赋值给新的NSString对象
15     NSString *plainText = [NSString stringWithFormat:@"pressing %@ button",title];
16     
17 //    _statusLabel.text = plainText;    //将格式化的字符串赋给标签的text属性
18     
19     //可变的字符串属性类,创建对象
20     NSMutableAttributedString *textStyle = [[NSMutableAttributedString alloc]initWithString:plainText];
21     
22     //NSDictionary字典新语法 @{}用于保存字符串属性..  NSArray 数组新语法是 @[]
23     NSDictionary *dict =
24     @{
25       NSFontAttributeName:[UIFont boldSystemFontOfSize:_statusLabel.font.pointSize]
26       };
27     
28     //取出plainText字符串中待改变的子字符串  即 title  也可以使用@""取出其他字符串
29     NSRange nameRange = [plainText rangeOfString:title];
30     
31     //设置字符串属性. 
32     [textStyle setAttributes:dict range:nameRange];
33     
34     _statusLabel.attributedText = textStyle;
35     
36     
37 }
38 @end