創建uilabel的分類

//豎著顯示

.h寫入

@property (nonatomic) NSString *verticalText;

.m寫入

- (NSString *)verticalText{

// 利用runtime添加屬性

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 = @"豎著";

iOS label的文字豎著顯示