ios 6和ios 5.1之间的核心文本差异？

Question

看来ios 5.1和ios 6之间的CoreText实现存在一些差异，正如您可以从这两个屏幕截图中看到的那样：

ios 6：

ios 5：

首先，文本颜色未正确应用。似乎在ios 5.1上，kCTForegroundColorAttributeName要求你给它一个CGColor，而在ios 6上，传递一个UIColor就足够了。所以我通过将代码更改为：

解决了这个问题

[attributes setObject:(id)[color CGColor] 
               forKey:(NSString*)kCTForegroundColorAttributeName];

其次，段落间距有点偏。 ＆＃34;视线＆＃34;之间的距离和＆＃34;根据＆＃34;是11px vs 25px（在屏幕截图中测量）。在两种情况下，段落间距都设置为5：

NSMutableData *styleSettingsArray = [NSMutableData data];
CGFloat spaceBefore,spaceAfter;
...
CTParagraphStyleSetting styleSettingB = {kCTParagraphStyleSpecifierParagraphSpacingBefore   ,sizeof(CGFloat),&spaceBefore};
CTParagraphStyleSetting styleSettingA = {kCTParagraphStyleSpecifierParagraphSpacing         ,sizeof(CGFloat),&spaceAfter};
[styleSettingsArray appendBytes:&styleSettingB length:sizeof(styleSettingB)];
[styleSettingsArray appendBytes:&styleSettingA length:sizeof(styleSettingA)];
...
if(styleSettingsArray.length > 0)
{
    CTParagraphStyleRef paragraphStyleRef = CTParagraphStyleCreate([styleSettingsArray bytes], [styleSettingsArray length] / sizeof(CTParagraphStyleSetting));
    [dictionary setObject:(__bridge id)(paragraphStyleRef) forKey:(NSString*)kCTParagraphStyleAttributeName];
    CFRelease(paragraphStyleRef);
}

控制台中paragraphStyleRef的说明：

iOS 6:
CTParagraphStyle:
base writing direction = -1, alignment = 3, line break mode = 0, default tab interval = 0
first line head indent = 0, head indent = 0, tail indent = 0
line height multiple = 0, maximum line height = 0, minimum line height = 0
line spacing adjustment = 0, paragraph spacing = 5, paragraph spacing before = 5


iOS 5:

CTParagraphStyle:
writing direction = -1, alignment = 3, line break mode = 0, default tab interval = 0
first line head indent = 0, head indent = 0, tail indent = 0
line height multiple = 0, maximum line height = 0, minimum line height = 0
line spacing adjustment = 0, paragraph spacing = 5, paragraph spacing before = 5

对我来说似乎是一样的，所以我不知道问题是什么。除了段落之间的间距，它们是相同的。

那我怎么解决这个问题呢？还有其他我应该注意的事情可能导致文本显示不同吗？

修改 经过一番调查后发现，段落造型的差异实际上是由于我的换行符打印出来的＆＃34; \ r \ n＆＃34;。将其改为＆＃34; \ n＆＃34;解决了间距问题。

Answer 1

Core Text在iOS 6中进行了大修。如果您拥有Apple开发者帐户，可以通过观看免费提供的WWDC 2012视频来查看所有更改。

现在在iOS 6中，您不能使用任何低级Core Text属性，如kCTForegroundColorAttributeName或kCTParagraphStyleAttributeName。

相反，您使用一组新的高级属性，例如NSForegroundColorAttributeName＆amp; NSParagraphStyle。

所以你的代码会改为：

/*Note that you have use the Foundation class
  for the attribute value instead of it's Core-Foundation counterpart.*/

[attributes setObject:color 
           forKey:NSForegroundColorAttributeName];

CGFloat spaceBefore, spaceAfter;

NSMutableParagraphStyle *mutableParagraphStyle = [NSMutableParagraphStyle defaultParagraphStyle];
mutableParagraphStyle.paragraphSpacing = spaceAfter;
mutableParagraphStyle.paragraphSpacingBefore = spaceBefore;

[attributes setObject:mutableParagraphStyle 
           forKey:NSParagraphStyleAttributeName];

您可以在此处找到所有新属性的文档：     http://developer.apple.com/library/ios/#documentation/uikit/reference/NSAttributedString_UIKit_Additions/Reference/Reference.html