如何在 UIView 上绘制一个 NSString 数组，它们之间没有任何前导空格并占据整个矩形？

Posted 2023-03-11

【中文标题】如何在 UIView 上绘制一个 NSString 数组，它们之间没有任何前导空格并占据整个矩形？

【英文标题】：How to draw an array of NSStrings on as UIView without any leading space between them and occupies the entire rect?

【发布时间】：2016-04-18 04:50:13

【问题描述】：

我想在 UIView 上以this 的形式绘制一个不同字体大小的字符串数组。我已经计算了要绘制的每个字符串所需的高度。示例中的字符串数组是 "Enter some text", "that", "will fit", "the rect"。我计算高度如下，

    @implementation NSString (Additions)

    - (CGFloat)heightForFont:(UIFont *)font 

    NSAttributedString *attrString = [[NSAttributedString alloc]initWithString:self attributes:@NSFontAttributeName:font];
    CTLineRef line = CTLineCreateWithAttributedString((__bridge CFAttributedStringRef)attrString);

    CGFloat ascent, descent, leading;
    CGFloat width = CTLineGetTypographicBounds(line, &ascent, &descent, &leading);
    CGFloat height = ascent + descent + leading;
    return height;
    

然后我尝试在 UIView 中绘制字符串，如下所示：

    - (void)drawStringArray:(NSArray *)splittedStringArray  maxYoFString:(CGFloat)maxY rect:(CGRect)rect fontsDict:(NSMutableDictionary *)fontsDict  
//Alter X origin if scaled
CGFloat originX = rect.origin.x;
CGRect drawRect = rect;
drawRect.origin.x = originX;
drawRect.origin.y = 0.0;
CGFloat heightForString = 0.0;
for (int i = 0; i < splittedStringArray.count; i++) 
    NSString *string =  splittedStringArray[i];
    UIFont *font = [fontsDict objectForKey:string];
    if(i < splittedStringArray.count -1)
    heightForString =  [string heightForFont:font];
    [string drawInRect:rect withAttributes:@
                                         NSFontAttributeName : font,
                                         NSForegroundColorAttributeName :self.random.currentTextColor
                                         ];
    drawRect.origin.y += heightForString;
    
    

但是在两行之间总是有一个空格。我想绘制没有任何前导空格的字符串。current image, expected image

【参考方案1】：

一个简单的解决方案是修补字体文件本身并确定其行高。在此处查看操作方法。

http://mbauman.net/geek/2009/03/15/minor-truetype-font-editing-on-a-mac/