iphone - 如何使用核心文本为PDF设置字体颜色和样式？

Question

如果我使用 core text 框架创建 PDF，它将不允许我设置颜色和字体样式。“核心文本”框架有问题吗？

我使用下面的代码来设置颜色:

CGContextRef    currentContext = UIGraphicsGetCurrentContext();
CGContextSetRGBFillColor(currentContext, 1.0, 0.0, 0.0, 1.0);  //This is not working.

Answer 1

试试下面的代码，在这段代码中我用 CTFontRef 改变了我的字体样式和大小

+(void)drawText:(NSString*)textToDraw inFrame:(CGRect)frameRect
{
    CFStringRef stringRef = ( CFStringRef)textToDraw;

    CGColorSpaceCreateWithName(stringRef);

    NSMutableAttributedString *string = [[NSMutableAttributedString alloc]
                                         initWithString:textToDraw];
    CTFontRef helveticaBold;
    helveticaBold = CTFontCreateWithName(CFSTR("Helvetica-Bold"), 24.0, NULL);
    [string addAttribute:(id)kCTFontAttributeName
                   value:(id)helveticaBold
                   range:NSMakeRange(0, [string length])];
    [string addAttribute:(id)kCTForegroundColorAttributeName
                   value:(id)[UIColor whiteColor].CGColor
                   range:NSMakeRange(0, [string length])];

    CTFramesetterRef framesetter =    CTFramesetterCreateWithAttributedString((CFAttributedStringRef)string);

    CGMutablePathRef framePath = CGPathCreateMutable();

    CGPathAddRect(framePath, NULL, frameRect);
    CFRange currentRange = CFRangeMake(0, 0);
    CTFrameRef frameRef = CTFramesetterCreateFrame(framesetter, currentRange, framePath, NULL);
    CGPathRelease(framePath);

    CGContextRef    currentContext = UIGraphicsGetCurrentContext();

    CGContextSetTextMatrix(currentContext, CGAffineTransformIdentity);

    CGContextTranslateCTM(currentContext, 0, frameRect.origin.y*2);

    CGContextScaleCTM(currentContext, 1.0, -1.0);

    CTFrameDraw(frameRef, currentContext);

    CGContextScaleCTM(currentContext, 1.0, -1.0);

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

    CFRelease(frameRef);
    CFRelease(string);
    CFRelease(framesetter);
}

您也可以点击此链接 Example

希望这对你有帮助，祝你编程愉快