Three20中的TTStyledTextLabel是什么？

在Three20中，有TTStyledTextLabel类，它相当于一个在IE中显示一段HTML的显示窗口，它的实现由两个部分来组成：

1.创建TTStyledTextLabel对象，并且将它增加到当前的View中。如下图及代码。

  NSString* kText =@"\

This is a test of styled labels.  Styled labels support \

<b>bold text</b>, <i>italic text</i>, <span class=\"blueText\">colored text</span>, \

<span class=\"largeText\">font sizes</span>, \

<span class=\"blueBox\">spans with backgrounds</span>, inline images \

<img src=\"bundle://smiley.png\"/>, and <a href=\"http://www.google.com\">hyperlinks</a> you can \

actually touch. URLs are automatically converted into links, like this: http://www.ccwit.com\

<div>You can enclose blocks within an HTML div.</div>\

Both line break characters\n\nand HTML line breaks<br/>are respected.";

  TTStyledTextLabel* label1 = [[[TTStyledTextLabelalloc]initWithFrame:self.view.bounds]autorelease];

  label1.font = [UIFontsystemFontOfSize:17];

  label1.text = [TTStyledTexttextFromXHTML:kText lineBreaks:YESURLs:YES];

  label1.contentInset =UIEdgeInsetsMake(10,10, 10, 10);

  [label1 sizeToFit];

  [self.viewaddSubview:label1];

2.label1对象中的显示text是通过style来进行控制的，也可以通过类来提供，如下：

@interface TextTestStyleSheet :TTDefaultStyleSheet

@end

@implementation TextTestStyleSheet

- (TTStyle*)blueText {

  return [TTTextStylestyleWithColor:[UIColorblueColor] next:nil];

}

- (TTStyle*)largeText {

  return [TTTextStylestyleWithFont:[UIFontsystemFontOfSize:32]next:nil];

}

- (TTStyle*)smallText {

  return [TTTextStylestyleWithFont:[UIFontsystemFontOfSize:12]next:nil];

}

- (TTStyle*)floated {

  return [TTBoxStylestyleWithMargin:UIEdgeInsetsMake(0,0, 5,5)

                    padding:UIEdgeInsetsMake(0,0, 0, 0)

                     minSize:CGSizeZeroposition:TTPositionFloatLeftnext:nil];

}

- (TTStyle*)blueBox {

  return

    [TTShapeStyle styleWithShape:[TTRoundedRectangleShapeshapeWithRadius:6]next:

    [TTInsetStylestyleWithInset:UIEdgeInsetsMake(0, -5, -4, -6) next:

    [TTShadowStylestyleWithColor:[UIColorgrayColor] blur:2offset:CGSizeMake(1,1)next:

    [TTSolidFillStylestyleWithColor:[UIColorpurpleColor] next:

    [TTSolidBorderStylestyleWithColor:[UIColorgrayColor] width:1next:nil]]]]];

}

- (TTStyle*)inlineBox {

  return

    [TTSolidFillStylestyleWithColor:[UIColorblueColor] next:

    [TTBoxStylestyleWithPadding:UIEdgeInsetsMake(5,13,5,13)next:

    [TTSolidBorderStylestyleWithColor:[UIColorblackColor] width:1next:nil]]];

}

- (TTStyle*)inlineBox2 {

  return

    [TTSolidFillStylestyleWithColor:[UIColorcyanColor] next:

    [TTBoxStylestyleWithMargin:UIEdgeInsetsMake(5,50,0,50)

               padding:UIEdgeInsetsMake(0,13,0,13)next:nil]];

}

@end

最后，别忘在在label1对象有效之前，调用

[TTStyleSheetsetGlobalStyleSheet:[[[TextTestStyleSheetalloc] init]autorelease]];

使label显示时使用TextTestStyleSheet提供的风格来显示。如下图所示的效果：