3

I'm using UIPrintPageRenderer sub-class to print html content on a pdf. How can i add a horizontal line on my printed content (both on header and footer)?

CGContextAddLineToPoint doesn't seem to work in UIPrintPageRenderer methods. Specifically those used to draw header and footer. NSString's drawAtPoint is working perfectly.

Here's what i've tried so far:

- (void)drawHeaderForPageAtIndex:(NSInteger)pageIndex inRect:(CGRect)headerRect {
    ...

    // Attempt 1 (Doesn't work!)
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetRGBFillColor(context, 1.0f, 1.0f, 1.0f, 1);
    CGContextSetRGBStrokeColor(context, 1.0f, 1.0f, 1.0f, 1);
    CGContextMoveToPoint(context, 10.0, 20.0);
    CGContextAddLineToPoint(context, 310.0, 20.0);

    // Attempt 2 (Doesn't work!)
    CGContextRef context = UIGraphicsGetCurrentContext();

    CGContextSetRGBFillColor(context, 1.0f, 1.0f, 1.0f, 1);
    CGContextSetRGBStrokeColor(context, 1.0f, 1.0f, 1.0f, 1);

    CGContextTranslateCTM(context, 0, headerRect.size.height);
    CGContextScaleCTM(context, 1, -1);

    CGContextMoveToPoint(context, 10.0, 20.0);
    CGContextAddLineToPoint(context, 310.0, 20.0);
}
4

3 に答える 3

1

In Core Graphics, a logical graphics elements are added to the context and then drawn. I see you adding a path to the context with e.g. CGContextAddLineToPoint(context, 310.0, 20.0);

This creates the path in memory, but to composite it to the screen you need to either fill or stroke the context's path. Try adding CGContextStrokePath(context); after to actually stoke the path.

于 2013-01-30T22:20:44.747 に答える
1

Just as regular drawing

- (void)drawHeaderForPageAtIndex:(NSInteger)pageIndex inRect:(CGRect)headerRect {

    CGContextRef context = UIGraphicsGetCurrentContext();

    CContextMoveToPoint(context, CGRectGetMinX(headerRect), 70);
    CGContextAddLineToPoint(context, CGRectGetMaxX(headerRect), 70);

    CGFloat grayScale = 0.5f;
    CGContextSetRGBStrokeColor(context, grayScale, grayScale, grayScale, 1);

    CGContextStrokePath(context);
}

Don't forget to CGStrokePath(...)

于 2015-06-01T07:01:58.873 に答える
0

だから、今のところ私は別の解決策を適用しました。CGContextを使用してこれを行う方法を知りたいです（画像をロードする必要はありません）。これが私の解決策です：

// Draw horizontal ruler in the header
UIImage *horizontalRule = [UIImage imageNamed:@"HorizontalRule.png"];
horizontalRule = [horizontalRule stretchableImageWithLeftCapWidth:0.5 topCapHeight:0];

CGFloat rulerX = CGRectGetMinX(headerRect) + HEADER_LEFT_TEXT_INSET;
CGFloat rulerY = self.printableRect.origin.y + fontSize.height + HEADER_FOOTER_MARGIN_PADDING + PRINT_RULER_MARGIN_PADDING;
CGFloat rulerWidth = headerRect.size.width - HEADER_LEFT_TEXT_INSET - HEADER_RIGHT_TEXT_INSET;
CGFloat rulerHeight = 1;
CGRect ruleRect = CGRectMake(rulerX, rulerY, rulerWidth, rulerHeight);

[horizontalRule drawInRect:ruleRect blendMode:kCGBlendModeNormal alpha:1.0];
于 2011-07-14T07:15:41.343 に答える