ios - 设置颜色 CFAttributedStringRef

Question

我有这个方法来绘制一个 Ant 填充的表格。我想要的是改变每一列中一个单词的颜色，但我不知道该怎么做。有朝一日可以帮帮我吗？任何帮助将不胜感激。

在我的应用程序中，用户可以从 segmente 控件中选择一些属性...我想导出他在 pdf 中选择的内容，比如表格。所以在每一行上都会选择一个单词

-(void)drawTableDataAt:(CGPoint)origin
         withRowHeight:(int)rowHeight
        andColumnWidth:(int)columnWidth
           andRowCount:(int)numberOfRows
        andColumnCount:(int)numberOfColumns
{
    int padding = 1;

    NSArray* headers = [NSArray arrayWithObjects:@"Grand", @"Taile ok", @"Petit", nil];
    NSArray* invoiceInfo1 = [NSArray arrayWithObjects:@"Extra", @"Bon", @"Ordi",  nil];
    NSArray* invoiceInfo2 = [NSArray arrayWithObjects:@"Gras", @"Etat", @"Maigre", nil];
    NSArray* invoiceInfo3 = [NSArray arrayWithObjects:@"Cru", @"Propre", @"Sale",  nil];
    NSArray* invoiceInfo4 = [NSArray arrayWithObjects:@"PLourd", @"PMoyen", @"PLeger", nil];
    NSArray* invoiceInfo5 = [NSArray arrayWithObjects:@"CSup", @"CEgal", @"CInf", nil];


    NSArray* allInfo = [NSArray arrayWithObjects:headers, invoiceInfo1, invoiceInfo2, invoiceInfo3, invoiceInfo4, invoiceInfo5,nil];

    for(int i = 0; i < [allInfo count]; i++)
    {
        NSArray* infoToDraw = [allInfo objectAtIndex:i];

        for (int j = 0; j < numberOfColumns; j++)
        {

            int newOriginX = origin.x + (j*columnWidth);
            int newOriginY = origin.y + ((i+1)*rowHeight);

            CGRect frame = CGRectMake(newOriginX + padding, newOriginY + padding, columnWidth, rowHeight);


            [self drawText:[infoToDraw objectAtIndex:j] inFrame:frame];
        }

    }

}

-(void)drawText:(NSString*)textToDraw inFrame:(CGRect)frameRect {

    CFStringRef stringRef = (__bridge CFStringRef)textToDraw;
    // Prepare the text using a Core Text Framesetter
    CFAttributedStringRef currentText = CFAttributedStringCreate(NULL, stringRef, NULL);
    CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(currentText);


    CGMutablePathRef framePath = CGPathCreateMutable();
    CGPathAddRect(framePath, NULL, frameRect);

    // Get the frame that will do the rendering.
    CFRange currentRange = CFRangeMake(0, 0);
    CTFrameRef frameRef = CTFramesetterCreateFrame(framesetter, currentRange, framePath, NULL);
    CGPathRelease(framePath);

    // Get the graphics context.
    CGContextRef    currentContext = UIGraphicsGetCurrentContext();

    // Put the text matrix into a known state. This ensures
    // that no old scaling factors are left in place.
    CGContextSetTextMatrix(currentContext, CGAffineTransformIdentity);


    // Core Text draws from the bottom-left corner up, so flip
    // the current transform prior to drawing.
    CGContextTranslateCTM(currentContext, 0, frameRect.origin.y*2);
    CGContextScaleCTM(currentContext, 1.0, -1.0);

    // Draw the frame.
    CTFrameDraw(frameRef, currentContext);

    CGContextScaleCTM(currentContext, 1.0, -1.0);
    CGContextTranslateCTM(currentContext, 0, (-1)*frameRect.origin.y*2);


    CFRelease(frameRef);
    CFRelease(stringRef);
    CFRelease(framesetter);
}

Answer 1

根据对问题的评论，您提到这些词永远不会改变。您可能会创建一大堆 if/else 语句来检查针对数组中的每个单词选择的每个单词。我把它作为一个更有效的替代方案，它应该很有希望工作。它可能需要一些调整，甚至需要一个循环来遍历你选择的单词，但这应该会让你朝着正确的方向前进:

//declare your textToDraw as a new NSString
NSString *str = textToDraw;
//Make an Array of the str by adding objects that are separated by whitespace
NSArray *words = [str componentsSeparatedByCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
//create a BOOL to check if your selected word exists in the array
BOOL wordExists = [words containsObject: @"%@", yourSelectedWord];

CTFramesetterRef framesetter = null;

//if the word exists, make it red
if(wordExists){

    NSUInteger indexOfTheString = [words indexOfObject: @"%@", yourSelectedWord];

    CFAttributedStringRef currentText = CFAttributedStringCreate(NULL,str, NULL);

    [currentText addAttribute:NSForegroundColorAttributeName 
         value:[UIColor redColor] 
         range:NSMakeRange(indexOfTheString, yourSelectedWord.length)];

    framesetter = CTFramesetterCreateWithAttributedString(currentText);

}

这会将找到的所选单词与数组中的正确单词进行匹配，并将其突出显示为红色。