6

私はコアテキストを使用して描画しようとしている次のコードを持っています。そのため、UILabel のようにテキストをクリップできません。言い換えれば、私は省略記号 ('...') を理解する必要があります。

 CGSize commentSize = [[self.sizeDictionary_ valueForKey:commentSizeKey] CGSizeValue];
        CGSize actualSize = [[self.sizeDictionary_ valueForKey:actualCommentSizeKey] CGSizeValue];

 NSString *actualComment = self.highlightItem_.comment;
        if (actualSize.height > commentSize.height){
            actualComment = [self.highlightItem_.comment stringByReplacingCharactersInRange:NSMakeRange(68, 3) withString:@"..."];
        }

CGSize に基づいて「...」の範囲を見つけるのに苦労しています。これを理解するための最良の方法は何ですか？

これが私がそれを描いている方法です：

CFStringRef string = CFBridgingRetain(actualComment);
        CFMutableAttributedStringRef comment = CFAttributedStringCreateMutable(kCFAllocatorDefault, 0);
        CFAttributedStringReplaceString (comment ,CFRangeMake(0, 0), string);

        CGColorRef blue = CGColorRetain([UIColor colorWithRed:131/255.f green:204/255.f blue:253/255.f alpha:1.0].CGColor);
        CGColorRef gray = CGColorRetain([UIColor colorWithWhite:165/255.f alpha:1.0].CGColor);

        CFAttributedStringSetAttribute(comment, CFRangeMake(0, [name length]),kCTForegroundColorAttributeName, blue);
        CFAttributedStringSetAttribute(comment, CFRangeMake([name length],  [self.highlightItem_.comment length] - [name length]),kCTForegroundColorAttributeName, gray);

        CGColorRelease (blue);
        CGColorRelease (gray);

        CTFontRef nameFont = CTFontCreateWithName(CFBridgingRetain(kProximaNovaBold), 13.0f, nil);
        CFAttributedStringSetAttribute(comment,CFRangeMake(0, [name length]),kCTFontAttributeName,nameFont);

        CTFontRef commentFont = CTFontCreateWithName(CFBridgingRetain(kProximaNovaRegular), 13.0f, nil);
        CFAttributedStringSetAttribute(comment, CFRangeMake([name length],  [self.highlightItem_.comment length] - [name length]),kCTFontAttributeName,commentFont);

        CGFloat commentYOffset = floorf((self.commentHeight_ - commentSize.height)/2);

        CGContextSaveGState(context);
        CGRect captionFrame = CGRectMake(0, 0, rect.size.width - 80, commentSize.height);
        CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(comment);
        CGMutablePathRef captionFramePath = CGPathCreateMutable();
        CGPathAddRect(captionFramePath, NULL, captionFrame);

        CTFrameRef mainCaptionFrame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, 0), captionFramePath, NULL);

        CGContextRef context = UIGraphicsGetCurrentContext();
        CGContextSetTextMatrix(context, CGAffineTransformIdentity);
        CGContextTranslateCTM(context, self.buttonSize_ + 25, self.imageHeight_ + self.commentHeight_ + 6 - commentYOffset);
        CGContextScaleCTM(context, 1.0, -1.0);

        CTFrameDraw(mainCaptionFrame, context);
        CGContextRestoreGState(context);
4

3 に答える 3

5

編集

（ここでの私の最初の回答は役に立ちませんでした。複数の行を処理していませんでした。歴史的な関心のために誰かがそれを見たい場合は、編集履歴を見てください。解決するよりも混乱を招くため、削除しました。現在の答えは正しいコードです。)

あなたがする必要があるのはCTFramesetter、最後の行を除くすべての行を解決することです. その後、必要に応じて最後の 1 つを手動で切り捨てることができます。

- (void)drawRect:(CGRect)rect
{
  CGContextRef context = UIGraphicsGetCurrentContext();
  CGContextSetTextMatrix(context, CGAffineTransformIdentity);

  CGRect pathRect = CGRectMake(50, 200, 200, 40);
  CGPathRef path = CGPathCreateWithRect(pathRect, NULL);

  CFAttributedStringRef attrString = (__bridge CFTypeRef)[self attributedString];

  // Create the framesetter using the attributed string
  CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(attrString);

  // Create a single frame using the entire string (CFRange(0,0))
  // that fits inside of path.
  CTFrameRef frame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, 0), path, NULL);

  // Draw the lines except the last one
  CFArrayRef lines = CTFrameGetLines(frame);
  CFIndex lineCount = CFArrayGetCount(lines);
  CGPoint origins[lineCount]; // I'm assuming that a stack variable is safe here.
                              // This would be bad if there were thousdands of lines, but that's unlikely.
  CTFrameGetLineOrigins(frame, CFRangeMake(0, 0), origins);
  for (CFIndex i = 0; i < lineCount - 1; ++i) {
    CGContextSetTextPosition(context, pathRect.origin.x + origins[i].x, pathRect.origin.y + origins[i].y);
    CTLineDraw(CFArrayGetValueAtIndex(lines, i), context);
  }

  ///
  /// HERE'S THE INTERESTING PART
  ///
  // Make a new last line that includes the rest of the string.
  // The last line is already truncated (just with no truncation mark), so we can't truncate it again
  CTLineRef lastLine = CFArrayGetValueAtIndex(lines, lineCount - 1);
  CFIndex lastLocation = CTLineGetStringRange(lastLine).location;
  CFRange restRange = CFRangeMake(lastLocation, CFAttributedStringGetLength(attrString) - lastLocation);
  CFAttributedStringRef restOfString = CFAttributedStringCreateWithSubstring(NULL, attrString, restRange);
  CTLineRef restLine = CTLineCreateWithAttributedString(restOfString);


  // We need to provide the truncation mark. This is an ellipsis (Cmd-semicolon).
  // You could also use "\u2026". Don't use dot-dot-dot. It'll work, it's just not correct.
  // Obviously you could cache this…
  CTLineRef ellipsis = CTLineCreateWithAttributedString((__bridge CFTypeRef)
                                                        [[NSAttributedString alloc] initWithString:@"…"]);

  // OK, now let's truncate it and draw it. I'm being a little sloppy here. If ellipsis could possibly
  // be wider than the path width, then this will fail and truncateLine will be NULL and we'll crash.
  // Don't do that.
  CTLineRef truncatedLine = CTLineCreateTruncatedLine(restLine,
                                                      CGRectGetWidth(pathRect),
                                                      kCTLineTruncationEnd,
                                                      ellipsis);
  CGContextSetTextPosition(context, pathRect.origin.x + origins[lineCount - 1].x, pathRect.origin.y + origins[lineCount - 1].y);
  CTLineDraw(truncatedLine, context);

  CFRelease(truncatedLine);
  CFRelease(ellipsis);
  CFRelease(restLine);
  CFRelease(restOfString);
  CFRelease(frame);
  CFRelease(framesetter);
  CGPathRelease(path);
}
于 2013-02-24T00:54:26.457 に答える
1

このようなものはどうですか...

- (NSString *)truncate:(NSString *)string toWidth:(CGFloat)width withFont:(UIFont *)font {

    CGSize size = [string sizeWithFont:font];
    if (size.width <= width) return string;

    NSString *truncatedString = [string copy];
    NSString *ellipticalString = [truncatedString stringByAppendingString:@"..."];
    size = [ellipticalString sizeWithFont:font];

    while (size.width > width && truncatedString.length) {
        truncatedString = [truncatedString substringToIndex:(truncatedString.length-1)];
        ellipticalString = [truncatedString stringByAppendingString:@"..."];
        size = [ellipticalString sizeWithFont:font];
    }
    return ellipticalString;
}
于 2013-02-24T01:30:06.387 に答える
0

最も簡単で簡単な方法は、

NSString *theText = @"bla blah bla bhla bla bla";
NSMutableParagraphStyle *style = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
[style setLineBreakMode:NSLineBreakByTruncatingTail];
[theText drawInRect:dirtyRect withAttributes:[NSDictionary dictionaryWithObjectsAndKeys:style, NSParagraphStyleAttributeName,nil]];

もっと_

于 2013-09-05T05:36:59.160 に答える