创建uilabel的分类

//竖着显示

.h写入

@property (nonatomic) NSString *verticalText;

.m写入

- (NSString *)verticalText{

    // 利用runtime添加属性

    return objc_getAssociatedObject(self, @selector(verticalText));

}

- (void)setVerticalText:(NSString *)verticalText{

    objc_setAssociatedObject(self, &verticalText, verticalText, OBJC_ASSOCIATION_RETAIN_NONATOMIC);

    NSMutableString *str = [[NSMutableString alloc] initWithString:verticalText];

    NSInteger count = str.length;

    for (int i = 1; i < count; i ++) {

        [str insertString:@"\n" atIndex:i*2-1];

    }

    self.text = str;

    self.numberOfLines = 0;

}

用法：label.verticalText = @"竖着";

iOS label的文字竖着显示