使用CALayer突出顯示跨越多行的UITextView中的文本

Question

這是在UITextView中獲取文本的CGRect的延續， 目的是使用CALayer進行突出顯示 。 我在為每個線段中的范圍獲取正確的矩形時遇到問題。

NSString* searchString = @"Returns the range of characters that generated";
NSRange match = [[[self textView]text]rangeOfString:searchString];
NSRange matchingGlyphRange = [manager glyphRangeForCharacterRange:match actualCharacterRange:NULL];



[manager enumerateLineFragmentsForGlyphRange:matchingGlyphRange usingBlock:
 ^(CGRect lineRect, CGRect usedRect, NSTextContainer *textContainer, NSRange lineRange, BOOL *stop) {

     NSRange currentRange = NSIntersectionRange(lineRange, matchingGlyphRange);

     [manager enumerateEnclosingRectsForGlyphRange:currentRange withinSelectedGlyphRange:NSMakeRange(NSNotFound, 0) inTextContainer:textContainer usingBlock:
      ^(CGRect rect, BOOL* stop) {
         if (usedRect.origin.y == rect.origin.y && NSLocationInRange(currentRange.location, lineRange)) {

             CGRect theRect = [manager boundingRectForGlyphRange:currentRange inTextContainer:textContainer];

             CALayer* roundRect = [CALayer layer];
             [roundRect setFrame:theRect];
             [roundRect setBounds:theRect];

             [roundRect setCornerRadius:5.0f];
             [roundRect setBackgroundColor:[[UIColor blueColor]CGColor]];
             [roundRect setOpacity:0.2f];
             [roundRect setBorderColor:[[UIColor blackColor]CGColor]];
             [roundRect setBorderWidth:3.0f];
             [roundRect setShadowColor:[[UIColor blackColor]CGColor]];
             [roundRect setShadowOffset:CGSizeMake(20.0f, 20.0f)];
             [roundRect setShadowOpacity:1.0f];
             [roundRect setShadowRadius:10.0f];

             [[[self textView]layer]addSublayer:roundRect];
             *stop = YES;
         }
     }];
}];

這是我目前的嘗試。 我基本上使用enumerateLineFragmentsForGlyphRange：usingBlock：循環遍歷每一行。 然后我使用enumerateEnclosingRectsForGlyphRange：withinSelectedGlyphRange：usingBlock：來確保當前行上的文本范圍與行的范圍匹配並具有相同的Y坐標。 有時這是有效的，有時則不然。

似乎如果搜索文本靠近返回，它會突出顯示高亮顯示。 （y坐標）。

在此屏幕截圖中，“返回生成的字符范圍”應突出顯示。

似乎文本不在返回或空格附近，這可以正常工作：

我錯過了什么嗎？

更新：

我把問題縮小了一點，我相信enumerateLineFragmentsForGlyphRange：usingBlock：正在跳過有返回的行。

Answer 1

我找到了解決方案：

而不是使用enumerateEnclosingRectsForGlyphRange：我使用NSString方法enumerateSubstringsInRange：options：usingBlock：

我像往常一樣枚舉行片段，但不是嘗試使用封閉的rect枚舉方法，而是在構建圖層的rect時枚舉行上的每個字符。

-(void)drawLayerForTextHighlightWithString:(NSString*)string {

for (CALayer* eachLayer in [self highlightLayers]) {
    [eachLayer removeFromSuperlayer];
}

NSLayoutManager* manager = [[self textView]layoutManager];

// Find the string
NSRange match = [[[self textView]text]rangeOfString:string options:
                 NSCaseInsensitiveSearch | NSDiacriticInsensitiveSearch | NSWidthInsensitiveSearch];

// Convert it to a glyph range
NSRange matchingGlyphRange = [manager glyphRangeForCharacterRange:match actualCharacterRange:NULL];

// Enumerate each line in that glyph range (this will fire for each line that the match spans)
[manager enumerateLineFragmentsForGlyphRange:matchingGlyphRange usingBlock:
 ^(CGRect lineRect, CGRect usedRect, NSTextContainer *textContainer, NSRange lineRange, BOOL *stop) {

     // currentRange uses NSIntersectionRange to return the range of the text that is on the current line
     NSRange currentRange = NSIntersectionRange(lineRange, matchingGlyphRange);

     // This rect will be built by enumerating each character in the line, and adding to it's width
     __block CGRect finalLineRect = CGRectZero;

     // Here we use enumerateSubstringsInRange:... to go through each glyph and build the final rect for the line
     [[[self textView]text]enumerateSubstringsInRange:currentRange options:NSStringEnumerationByComposedCharacterSequences usingBlock:
      ^(NSString* substring, NSRange substringRange, NSRange enclostingRange, BOOL* stop) {

          // The range of the single glyph being enumerated
          NSRange singleGlyphRange =  [manager glyphRangeForCharacterRange:substringRange actualCharacterRange:NULL];

          // get the rect for that glyph
          CGRect glyphRect = [manager boundingRectForGlyphRange:singleGlyphRange inTextContainer:textContainer];

          // check to see if this is the first iteration, if not add the width to the final rect for the line
          if (CGRectEqualToRect(finalLineRect, CGRectZero)) {
              finalLineRect = glyphRect;
          } else {
              finalLineRect.size.width += glyphRect.size.width;
          }

      }];

     // once we get the rect for the line, draw the layer
     UIEdgeInsets textContainerInset = [[self textView]textContainerInset];
     finalLineRect.origin.x += textContainerInset.left;
     finalLineRect.origin.y += textContainerInset.top;

     CALayer* roundRect = [CALayer layer];
     [roundRect setFrame:finalLineRect];
     [roundRect setBounds:finalLineRect];

     [roundRect setCornerRadius:5.0f];
     [roundRect setBackgroundColor:[[UIColor blueColor]CGColor]];
     [roundRect setOpacity:0.2f];
     [roundRect setBorderColor:[[UIColor blackColor]CGColor]];
     [roundRect setBorderWidth:3.0f];
     [roundRect setShadowColor:[[UIColor blackColor]CGColor]];
     [roundRect setShadowOffset:CGSizeMake(20.0f, 20.0f)];
     [roundRect setShadowOpacity:1.0f];
     [roundRect setShadowRadius:10.0f];

     [[[self textView]layer]addSublayer:roundRect];
     [[self highlightLayers]addObject:roundRect];

     // continues for each line
 }];

}

我還在進行多項比賽，一旦我開始工作，我就會更新代碼。