.h文件
+ (CGSize)sizeForString:(NSString *)string
limitSize:(CGSize)sz
font:(UIFont *)ft
lineBreakMode:(NSLineBreakMode)lineBreakMode
alignment:(NSTextAlignment)alignment;
.m 文件
+ (CGSize)sizeForString:(NSString *)string
limitSize:(CGSize)sz
font:(UIFont *)ft
lineBreakMode:(NSLineBreakMode)lineBreakMode
alignment:(NSTextAlignment)alignment {
CGSize boundSize = CGSizeMake(sz.width, sz.height);
CGSize resultSize = CGSizeZero;
if ([NSString instancesRespondToSelector:@selector(boundingRectWithSize:options:attributes:context:)]) {
NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
style.lineBreakMode = lineBreakMode;
style.lineSpacing = 0;
style.alignment = alignment;
NSDictionary *attribute = @{NSFontAttributeName:ft,
NSParagraphStyleAttributeName:style};
CGRect rect = [string boundingRectWithSize:boundSize
options:NSStringDrawingUsesLineFragmentOrigin
attributes:attribute
context:nil];
resultSize = CGSizeMake(ceil(rect.size.width), ceil(rect.size.height));
}else {
resultSize = [string sizeWithFont:ft
constrainedToSize:boundSize
lineBreakMode:lineBreakMode];
}
resultSize = CGSizeMake(MIN(sz.width,resultSize.width),
resultSize.height);
return resultSize;
}
