1、UILabel行間距問題：設計師要求UILabel要有行間距，但是UILabel是沒有這么一個直接暴露的屬性的，想要修改lineSpacing，我們需要借助NSAttributedString來實現(xiàn)，需要注意計算文字上下留白，示意代碼：
NSMutableParagraphStyle *paragraphStyle = [NSMutableParagraphStyle new];
paragraphStyle.lineSpacing = 10 - (label.font.lineHeight - label.font.pointSize);
NSMutableDictionary *attributes = [NSMutableDictionary dictionary];
[attributes setObject:paragraphStyle forKey:NSParagraphStyleAttributeName];
label.attributedText = [[NSAttributedString alloc] initWithString:label.text attributes:attributes];
2、UILabel內邊距問題：自定義UILabel，然后重寫drawTextInRect，示意代碼：
import "CustomLabel.h"
@implementation CustomLabel
- (instancetype)initWithFrame: (CGRect)frame {
if (self = [super initWithFrame: frame]) {
_textInsets = UIEdgeInsetsZero;
}
} - (void)drawTextInRect: (CGRect)rect {
[super drawTextInRect: UIEdgeInsetsInsetRect(rect, _textInsets)];
}
@end
3、YYLabel、YYText
4、UITextView行間距問題，光標問題：
可以使用，
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.headIndent = 15; // <--- indention if you need it
paragraphStyle.firstLineHeadIndent = 15;
paragraphStyle.lineSpacing = 7; // <--- magic line spacing here!
NSDictionary *attrsDictionary =
@{ NSParagraphStyleAttributeName: paragraphStyle }; // <-- there are many more attrs, e.g NSFontAttributeName
self.textView.attributedText = [[NSAttributedString alloc] initWithString:@"Hello World over many lines!" attributes:attrsDictionary];
或者可以創(chuàng)建一個重新實現(xiàn)[UITextView styleString]的子類：
@implementation MBTextView
- (id)styleString {
return [[super styleString] stringByAppendingString:@"; line-height: 1.2em"];
}
@end
5、字間距問題：
NSString *labelText = label.text;
NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:labelText attributes:@{NSKernAttributeName:@(space)}];
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
[attributedString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, [labelText length])];
label.attributedText = attributedString;
[label sizeToFit];
6、行高計算：
使用 string.boundingRect 方法。
