sizeWithFont:替换

Question

以下NSString方法已在iOS 7中被废弃：

    - (CGSize)sizeWithFont:(UIFont *)font NS_DEPRECATED_IOS(2_0, 7_0, "Use -sizeWithAttributes:");

    - (CGSize)sizeWithFont:(UIFont *)font forWidth:(CGFloat)width lineBreakMode:
(NSLineBreakMode)lineBreakMode NS_DEPRECATED_IOS(2_0, 7_0, "Use -boundingRectWithSize:options:attributes:context:");

    - (CGSize)sizeWithFont:(UIFont *)font constrainedToSize:(CGSize)size NS_DEPRECATED_IOS(2_0, 7_0, "Use -boundingRectWithSize:options:attributes:context:");

    - (CGSize)sizeWithFont:(UIFont *)font constrainedToSize:(CGSize)size lineBreakMode:(NSLineBreakMode)lineBreakMode NS_DEPRECATED_IOS(2_0, 7_0, "Use -boundingRectWithSize:options:attributes:context:"); 

虽然第一种的替代方法很简单，但其他的就不那么简单了。要获得完全相同的结果，对boundingRectWithSize:options:attributes:context:的等效调用是什么？

特别是：

• options的价值应该是什么？
• 如何指定lineBreakMode

Answer 1

.How，您指定了lineBreakMode吗？

NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
[paragraphStyle setLineBreakMode:NSLineBreakByTruncatingTail];
[attributedStr addAttribute:NSParagraphStyleAttributeName
                 value:paragraphStyle
                 range:NSMakeRange(0,[attributedStr length])];

Answer 2

加上这个

UIFont *font = [UIFont boldSystemFontOfSize:16];
CGRect new = [string boundingRectWithSize:CGSizeMake(200, 300) options:NSStringDrawingUsesFontLeading attributes:@{NSFontAttributeName: font} context:nil];
CGSize stringSize= new.size;