iOS --图文混排

图文混排实现方式

• core Text
  • ios 6.0 之前，纯C语言，不易用，不推荐使用
• NSAttributedString
  • ios 6.0 开始，简单易用
• TextKit
  • ios7 开始，功能强大，简单易用
• UIWebView
  • 利用UIWebView加载HTML实现图文混排
  • 但是注意：UIWebView本身有内存问题，占用内存相比较而较大不推荐,但是使用比较灵活

1、不可变的属性文字 NSAttributedString

    NSMutableDictionary *attrs = [NSMutableDictionary dictionary];
    attrs[NSForegroundColorAttributeName] = [UIColor grayColor];
    attrs[NSUnderlineStyleAttributeName] = @1;
    attrs[NSUnderlineColorAttributeName] = [UIColor redColor];
    self.attributedPlaceholder = [[NSAttributedString alloc] initWithString:self.placeholder attributes:attrs];

2、可变的属性文字 NSMutableAttributedString

    NSMutableAttributedString *string = [[NSMutableAttributedString alloc] initWithString:self.placeholder];
    [string addAttribute:NSForegroundColorAttributeName value:[UIColor redColor] range:NSMakeRange(0, 1)];
    [string addAttribute:NSForegroundColorAttributeName value:[UIColor greenColor] range:NSMakeRange(1, 1)];
    [string addAttribute:NSFontAttributeName value:[UIFont boldSystemFontOfSize:30] range:NSMakeRange(1, 1)];
    self.attributedPlaceholder = string;

3、图文混排

• 图解：

  
  
  

  Snip20150902_94.png
  
  
  

• 注意：

  
  
  

  Snip20150902_96.png

• 实现：

  // 富文本用法3 - 图文混排
    NSMutableAttributedString *string = [[NSMutableAttributedString alloc] init];

    // 第二段：图片
    NSTextAttachment *attachment = [[NSTextAttachment alloc] init];
    attachment.image = [UIImage imageNamed:@"login_close_icon"];
    attachment.bounds = CGRectMake(0, 0, 16, 16);
    NSAttributedString *subtring2 = [NSAttributedString attributedStringWithAttachment:attachment];
    [string appendAttributedString:subtring2];

    // 第一段：placeholder
    NSAttributedString *substring1 = [[NSAttributedString alloc] initWithString:self.placeholder];
    [string appendAttributedString:substring1];

    // 第三段：哈哈
    NSAttributedString *substring3 = [[NSAttributedString alloc] initWithString:@"哈哈"];
    [string appendAttributedString:substring3];

    self.attributedPlaceholder = string;