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我现在在 iOS 的打印界面上苦苦挣扎。我拥有的是一个带有自定义 UIView 的视图控制器,它在 drawRect 中进行绘图:

此处为绘图在 iPad 上的外观示例(包括一些彩色测试线):

在此处输入图像描述

我设置了一个 UIPrintRenderer 子类,它打印页眉和页脚,并为自定义 UIView 的 drawRect: 方法提供内容矩形 drawContentForPageAtIndex:inRect:。调试器告诉我,drawRect: 总是被调用——不管 rect drawContentForPageAtIndex:inRect: 是否存在于渲染器类中。所以我不在 rect drawContentForPageAtIndex:inRect: 中进行绘图,我使用 drawRect: 。

当打印机模拟器提供 A4 纸张格式时,我得到 [0, 0, 841.89, 595.276] 的纸张矩形,[11.9905, 11.9906, 817.909, 571.294] 的可打印矩形和 [11.9905, 33.9906, 817.909, 530.294] 的内容矩形]。我确实不明白的是, drawRect: 从打印界面获取 [0, 0, 695, 530.294] 的矩形。那是内容矩形的高度,但宽度是正常绘制时不打印时从矩形开始的高度:[0, 0, 695, 648]。在模拟器输出页面是这样的(当然也添加了一些测试帧、线和圆):

在此处输入图像描述

下面是一些代码,首先是视图控制器中设置打印的部分:

- (IBAction)pressedPrint:(id)sender
{
    UIPrintInteractionController*   printCtrl = [UIPrintInteractionController sharedPrintController];
    UIPrintInfo*                    printInfo = [UIPrintInfo printInfo];

    NSLog(@"%s prepare printing parameters etc.", __func__);
    printCtrl.delegate       = self;
    printInfo.outputType     = UIPrintInfoOutputPhoto;
    printInfo.orientation    = UIPrintInfoOrientationLandscape;
    printInfo.jobName        = [NSString stringWithFormat:@"%@ - %@", NSLocalizedString(@"NavTitleMain", @""), self.title];
    printInfo.duplex         = UIPrintInfoDuplexNone;
    printCtrl.printInfo      = printInfo;
    printCtrl.showsPageRange = NO;

    // This code uses a custom UIPrintPageRenderer so that it can draw a header and footer.
    DVPrintPageRenderer*    myRenderer = [[DVPrintPageRenderer alloc] init];

    // The DVPrintPageRenderer class provides a jobtitle that it will label each page with.
    myRenderer.jobTitle      = printInfo.jobName;
    myRenderer.isTwoPageView = NO;
    myRenderer.footerText    = [centralDocument sharedInstance].docTitle;
    myRenderer.drawView      = self.drawArea;

    // To draw the content of each page, a UIViewPrintFormatter is used.
    UIViewPrintFormatter*   viewFormatter = [self.drawArea viewPrintFormatter];
    UIFont*                 titleFont     = [UIFont fontWithName:@"Helvetica" size:HEADER_TEXT_HEIGHT];
    CGSize                  titleSize     = [myRenderer.jobTitle getSizeWithFont:titleFont];
    UIFont*                 footerFont    = [UIFont fontWithName:@"Helvetica" size:FOOTER_TEXT_HEIGHT];
    CGSize                  footerSize    = [myRenderer.footerText getSizeWithFont:footerFont];

    viewFormatter.startPage = 0;
    myRenderer.headerHeight = titleSize.height  + HEADER_FOOTER_MARGIN_PADDING;
    myRenderer.footerHeight = footerSize.height + HEADER_FOOTER_MARGIN_PADDING;
    [myRenderer addPrintFormatter:viewFormatter startingAtPageAtIndex:0];
    // Set our custom renderer as the printPageRenderer for the print job.
    printCtrl.printPageRenderer = myRenderer;
    drawArea.isPrinting     = YES;
    drawArea.printRenderer  = myRenderer;
    NSLog(@"%s before presenting the printer dialog", __func__);

    void (^completionHandler)(UIPrintInteractionController*, BOOL, NSError*) =
    ^(UIPrintInteractionController* printController, BOOL completed, NSError* error)
    {
        drawArea.isPrinting    = NO;
        drawArea.printRenderer = nil;

        if (!completed && error)
        {
            NSLog(@"Printing could not complete because of error: %@", error);
        }
    };

    if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
    {
        [printCtrl presentFromBarButtonItem:sender animated:YES completionHandler:completionHandler];
    }
    else
    {
        [printCtrl presentAnimated:YES completionHandler:completionHandler];
    }
}

drawRect: 的第一个代码部分也可能与此处相关:

- (void)drawRect: (CGRect)rect
{
    // Drawing code.
    NSLog(@"%s entered for %@", __func__, (isPrinting ? @"printing" : @"screen drawing"));
    NSInteger   colorCount = (colorArray  == nil) ? -1 : [colorArray count];
    NSInteger   graphCount = (graphPoints == nil) ? -1 : [graphPoints count];

    CGContextRef    context = UIGraphicsGetCurrentContext();

    CGContextSaveGState(context);

    if (isPrinting)
    {
        // make sure that we'll print the frame rectangle
        CGRect  newRect = CGRectInset(printRenderer.rectContent, 2.0, 2.0);

        saveGraphRect = drawGraphRect;
        saveBackColor = viewBackColor;
        saveTextColor = viewBackColor;
        CGContextTranslateCTM(context, printRenderer.rectContent.origin.x, -printRenderer.rectContent.origin.y);
        NSLog(@"%s content = [%g, %g, %g, %g]", __func__,
              printRenderer.rectContent.origin.x, printRenderer.rectContent.origin.y,
              printRenderer.rectContent.size.width, printRenderer.rectContent.size.height);
        NSLog(@"%s rect(1) = [%g, %g, %g, %g]", __func__,
              rect.origin.x, rect.origin.y, rect.size.width, rect.size.height);
        rect          = CGRectMake(ceilf(newRect.origin.x),    ceilf(newRect.origin.y),
                                   floorf(newRect.size.width), floorf(newRect.size.height));
        CGContextTranslateCTM(context, rect.origin.x, rect.origin.y);
        rect.origin   = CGPointMake(0.0, 0.0);

        usedBounds    = rect;
        drawGraphRect = [self makeInsetDrawRectFrom:rect];
        viewBackColor = [UIColor whiteColor];
        axisTextColor = [UIColor blackColor];
        NSLog(@"%s prepared for printing", __func__);
        NSLog(@"%s bounds = [%g, %g, %g, %g]", __func__,
              self.bounds.origin.x, self.bounds.origin.y,
              self.bounds.size.width, self.bounds.size.height);
        NSLog(@"%s paper = [%g, %g, %g, %g]", __func__,
              printRenderer.paperRect.origin.x, printRenderer.paperRect.origin.y,
              printRenderer.paperRect.size.width, printRenderer.paperRect.size.height);
        NSLog(@"%s rect(2) = [%g, %g, %g, %g]", __func__,
              rect.origin.x, rect.origin.y, rect.size.width, rect.size.height);
        NSLog(@"%s draw = [%g, %g, %g, %g]", __func__,
              drawGraphRect.origin.x, drawGraphRect.origin.y, drawGraphRect.size.width, drawGraphRect.size.height);
    }
    else
    {
        usedBounds = self.bounds;
        ...

drawRect: 中矩形的 NSLog 输出也相关:

2014-01-21 17:15:39.906 iELANA[19015:a0b] -[DrawView drawRect:] entered for screen drawing
2014-01-21 17:15:39.906 iELANA[19015:a0b] -[DrawView drawRect:] bounds = [0, 0, 695, 648]
2014-01-21 17:15:39.906 iELANA[19015:a0b] -[DrawView drawRect:] rect = [0, 0, 695, 648]
2014-01-21 17:15:39.906 iELANA[19015:a0b] -[DrawView drawRect:] draw = [62, 2, 631, 584]
2014-01-21 17:15:40.645 iELANA[19015:a0b] -[viewDiagram pressedPrint:] prepare printing parameters etc.
2014-01-21 17:15:40.645 iELANA[19015:a0b] -[viewDiagram pressedPrint:] before presenting the printer dialog
2014-01-21 17:15:46.131 iELANA[19015:a0b] printableRect = [11.9905, 11.9906, 817.909, 571.294]
2014-01-21 17:15:46.131 iELANA[19015:a0b] headerRect = [11.9905, 11.9906, 817.909, 22]
2014-01-21 17:15:46.131 iELANA[19015:a0b] header text size = [297, 17]
2014-01-21 17:15:46.133 iELANA[19015:a0b] -[DVPrintPageRenderer drawContentForPageAtIndex:inRect:] page = 0, rect [11.9905, 33.9906, 817.909, 530.294]
2014-01-21 17:15:46.133 iELANA[19015:a0b] paper     rect = [0, 0, 841.89, 595.276]
2014-01-21 17:15:46.133 iELANA[19015:a0b] printable rect = [11.9905, 11.9906, 817.909, 571.294]
2014-01-21 17:15:46.133 iELANA[19015:a0b] -[DrawView drawRect:] entered for printing
2014-01-21 17:15:46.134 iELANA[19015:a0b] -[DrawView drawRect:] content = [11.9905, 33.9906, 817.909, 530.294]
2014-01-21 17:15:46.134 iELANA[19015:a0b] -[DrawView drawRect:] rect(1) = [0, 0, 695, 530.294]
2014-01-21 17:15:46.134 iELANA[19015:a0b] -[DrawView drawRect:] prepared for printing
2014-01-21 17:15:46.134 iELANA[19015:a0b] -[DrawView drawRect:] bounds = [0, 0, 695, 648]
2014-01-21 17:15:46.134 iELANA[19015:a0b] -[DrawView drawRect:] paper = [0, 0, 841.89, 595.276]
2014-01-21 17:15:46.134 iELANA[19015:a0b] -[DrawView drawRect:] rect(2) = [0, 0, 813, 526]
2014-01-21 17:15:46.135 iELANA[19015:a0b] -[DrawView drawRect:] draw = [62, 2, 749, 462]
2014-01-21 17:15:46.140 iELANA[19015:a0b] printableRect = [11.9905, 11.9906, 817.909, 571.294]
2014-01-21 17:15:46.140 iELANA[19015:a0b] footerRect = [11.9905, 564.285, 817.909, 19]
2014-01-21 17:15:46.140 iELANA[19015:a0b] footer text size = [296, 14]

绘图代码使用 Core Graphics 和 UIKit 来绘制框架、线条等。文本输出使用 Core Text。因此,应用正确的 CTM 转换仍有一些工作要做。但主要的第一个问题是:

为什么 drawRect: 从打印界面获取一个奇怪的矩形而不是内容矩形?如果我不能打破这条规则,那么 iPhone 打印而不是 iPad 会变得非常糟糕——使用当前编码的 iPhone 看起来更糟。

我是否应该在打印渲染器的 drawContentForPageAtIndex:inRect: 中更好地执行打印绘图代码?

非常感谢您的帮助:-)

康兰

添加:

似乎确实如此,传递给 drawRect: 的图形上下文不适用于打印要求。当我直接从drawRect返回时:在打印的情况下并将打印代码添加到drawContentForPageAtIndex:inRect:,我得到一个更好的(测试)输出:

在此处输入图像描述

但是我不明白并且仍然需要您帮助的是轴文本的定位代码,这些代码是使用 Core Text 绘制的。我尝试了非常不同的 CTM 转换组合......但我使用的任何组合都会导致文本定位错误。这就是我为 x 轴上的文本输出所做的:

- (void)drawAxisValueXin: (CGContextRef)context withText: (NSString*)axisValueX dockToPoint: (CGPoint)dockPoint
{
    BOOL        isRetina  = (!isPrinting && AfxGetApp().isRetina);
    CGFloat     rMul      = (isRetina) ? 2.0 : 1.0;
    CGFloat     fontSize  = 10.0;
    CTFontRef   helvetica = CTFontCreateWithName(CFSTR("Helvetica"), fontSize, NULL);

    if (isRetina)
    {
        dockPoint.x *= 2.0;
        dockPoint.y *= 2.0;
    }

    // flip the coordinate system
    CGContextSaveGState(context);

    if (isPrinting)
    {
        CGContextSetTextMatrix(context, CGAffineTransformIdentity);
        CGContextTranslateCTM(context, 0.0f, CGRectGetHeight(printRenderer.paperRect));
        CGContextScaleCTM(context, 1.0f, -1.0f);
    }
    else
    {
        CGContextSetTextMatrix(context, CGAffineTransformIdentity);
        CGContextTranslateCTM(context, 0.0f, CGRectGetHeight(usedBounds) * rMul);
        CGContextScaleCTM(context, 1.0f, -1.0f);
    }

    // make the attributed string
    NSMutableAttributedString*  attrString = [[NSMutableAttributedString alloc] initWithString:axisValueX];
    NSRange                     strRange   = NSMakeRange(0, [attrString length]);

    [attrString addAttribute: (id)kCTFontAttributeName
                       value: (__bridge id)helvetica
                       range: strRange];
    [attrString addAttribute: (id)kCTForegroundColorAttributeName
                       value: (id)axisTextColor.CGColor
                       range: strRange];

    // draw the text
    CTLineRef   ctLine    = CTLineCreateWithAttributedString((CFAttributedStringRef)attrString);
    CGFloat     ascent;
    CGFloat     descent;
    CGFloat     width     = ceilf(CTLineGetTypographicBounds(ctLine, &ascent, &descent, NULL));
    CGFloat     height    = ceilf(ascent + descent);
    CGSize      textSize  = CGSizeMake(width, height);
    CGPoint     atPoint   = CGPointMake(dockPoint.x + (1.0 - textSize.width) * rMul,
                                        dockPoint.y + (10.0 - 2.0) * rMul); // x = text right edge, y = text mid
    CGPoint     userPoint = CGContextConvertPointToUserSpace(context, atPoint);

    if (fabsf(tiltLeftAxisX) > 1.0e-8)
    {
        CGContextRotateCTM(context, -tiltLeftAxisX);
        dockPoint.y += 2.0 * rMul;      // offset y 2 points down
        dockPoint = CGContextConvertPointToUserSpace(context, dockPoint);
        dockPoint.x = nearbyintf(dockPoint.x);
        dockPoint.y = nearbyintf(dockPoint.y);
        userPoint = CGPointMake(dockPoint.x - width,
                                dockPoint.y - height / 2.0);
    }

    CGContextSetTextPosition(context, userPoint.x, userPoint.y);
    CTLineDraw(ctLine, context);

    CGRect  rectTempl = CGRectMake(-5.0, -5.0, 10.0, 10.0);
    CGRect  rectDot   = CGRectOffset(rectTempl, userPoint.x, userPoint.y);

    [[UIColor redColor] set];
    CGContextFillEllipseInRect(context, rectDot);
    rectDot = CGRectOffset(rectTempl, atPoint.x, atPoint.y);
    [[UIColor greenColor] set];
    CGContextFillEllipseInRect(context, rectDot);

    // clean up
    CFRelease(ctLine);
    CFRelease(helvetica);
    CGContextRestoreGState(context);
}
4

1 回答 1

0

打印上下文与绘图上下文非常不同。因此,上述方法最终可行的结论是这样的:

- (void)drawAxisValueXin: (CGContextRef)context withText: (NSString*)axisValueX dockToPoint: (CGPoint)dockPoint
{
    BOOL        isRetina  = (!isPrinting && AfxGetApp().isRetina);
    CGFloat     rMul      = (isRetina) ? 2.0 : 1.0;
    CGFloat     fontSize  = 10.0;
    CTFontRef   helvetica = CTFontCreateWithName(CFSTR("Helvetica"), fontSize, NULL);

    if (isRetina)
    {
        dockPoint.x *= 2.0;
        dockPoint.y *= 2.0;
    }
    else if (isPrinting)
    {
        dockPoint.y += 2.0;
    }

    // flip the coordinate system
    CGContextSaveGState(context);

    if (isPrinting)
    {
        CGContextSetTextMatrix(context, CGAffineTransformMakeScale(1.0, -1.0));
    }
    else
    {
        CGContextSetTextMatrix(context, CGAffineTransformIdentity);
        CGContextTranslateCTM(context, 0.0f, CGRectGetHeight(usedBounds) * rMul);
        CGContextScaleCTM(context, 1.0f, -1.0f);
    }

    // make the attributed string
    NSMutableAttributedString*  attrString = [[NSMutableAttributedString alloc] initWithString:axisValueX];
    NSRange                     strRange   = NSMakeRange(0, [attrString length]);

    [attrString addAttribute: (id)kCTFontAttributeName
                       value: (__bridge id)helvetica
                       range: strRange];
    [attrString addAttribute: (id)kCTForegroundColorAttributeName
                       value: (id)axisTextColor.CGColor
                       range: strRange];

    // draw the text
    CTLineRef   ctLine    = CTLineCreateWithAttributedString((CFAttributedStringRef)attrString);
    CGFloat     ascent;
    CGFloat     descent;
    CGFloat     width     = ceilf(CTLineGetTypographicBounds(ctLine, &ascent, &descent, NULL));
    CGFloat     height    = ceilf(ascent + descent);
    CGSize      textSize  = CGSizeMake(width, height);
    CGPoint     atPoint   = CGPointMake(dockPoint.x + (1.0 - textSize.width) * rMul,
                                        dockPoint.y + (10.0 - 2.0) * rMul); // x = text right edge, y = text mid
    CGPoint     userPoint = (isPrinting) ? atPoint : CGContextConvertPointToUserSpace(context, atPoint);

    if (fabsf(tiltLeftAxisX) > 1.0e-8)
    {
        if (isPrinting)
        {
            CGFloat xMove = textSize.height * sin(tiltLeftAxisX);
            CGFloat yMove = textSize.width  * sin(tiltLeftAxisX);

            userPoint.x -= xMove;
            userPoint.y -= yMove;
            userPoint    = CGContextConvertPointToDeviceSpace(context, userPoint);
            CGContextRotateCTM(context, tiltLeftAxisX);
            userPoint    = CGContextConvertPointToUserSpace(context, userPoint);
        }
        else
        {
            CGContextRotateCTM(context, -tiltLeftAxisX);
            dockPoint.y += 2.0 * rMul;      // offset y 2 points down
            dockPoint    = CGContextConvertPointToUserSpace(context, dockPoint);
            dockPoint.x  = nearbyintf(dockPoint.x);
            dockPoint.y  = nearbyintf(dockPoint.y);
            userPoint    = CGPointMake(dockPoint.x - width,
                                       dockPoint.y - height / 2.0);
        }
    }

    CGContextSetTextPosition(context, userPoint.x, userPoint.y);
    CTLineDraw(ctLine, context);

    // clean up
    CFRelease(ctLine);
    CFRelease(helvetica);
    CGContextRestoreGState(context);
}
于 2014-01-27T11:52:42.037 回答