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複数のフォーマッター ( UIViewPrintFormatter、UIMarkupTextPrintFormatter、UISimpleTextPrintFormatter) をページ レンダラー ( UIPrintPageRenderer) で使用してコンテンツを印刷しようとした人はいますか?

UIMarkupTextPrintFormattersサブクラスで twoを使用しようとしてUIPrintPageRendererいますが、印刷に失敗しています。PrintWebViewサンプル コードMyPrintPageRendererのクラスを使用しています。

Apple のドキュメントを一読しましたが、あまり役に立ちませんでした。また、説明に関連するサンプル コードもありません。いくつかの解決策を試しましたが、これまでのところ成功していません。

助言がありますか？

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3 に答える 3

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The fact that there is very little activity in the "Printing" section suggests that either not many people are using this, or people using this API are not visiting this community, or people are just ignoring the question for some reason.

Anyways, i was able to solve my problem. I was using setPrintFormatters: method earlier which wasn't/isn't working. I don't know why. So, i started experimenting with addPrintFormatter:startingAtPageAtIndex: method instead. And here's how i solved my problem:

// To draw the content of each page, a UIMarkupTextPrintFormatter is used.
NSString *htmlString = [self prepareWebViewHTML];
UIMarkupTextPrintFormatter *htmlFormatter = [[UIMarkupTextPrintFormatter alloc] initWithMarkupText:htmlString];

NSString *listHtmlString = [self prepareWebViewListHTMLWithCSS];
UIMarkupTextPrintFormatter *listHtmlFormatter = [[UIMarkupTextPrintFormatter alloc] initWithMarkupText:listHtmlString];

// I think this should work, but it doesn't! The result is an empty page with just the header and footer text.
// [myRenderer setPrintFormatters:[NSArray arrayWithObjects:htmlFormatter, listHtmlFormatter, nil]];

// Alternatively, i've used addPrintFormatters here, and they just work!
// Note: See MyPrintPageRenderer's numberOfPages method implementation for relavent details.
// The important point to note there is that the startPage property is updated/corrected.
[myRenderer addPrintFormatter:htmlFormatter startingAtPageAtIndex:0];
[myRenderer addPrintFormatter:listHtmlFormatter startingAtPageAtIndex:1];

In the MyPrintPageRenderer, i used following code to update/correct the startPage property so that a new page is used for each formatter:

- (NSInteger)numberOfPages
{
    // TODO: Perform header footer calculations
    // . . .

    NSUInteger startPage = 0;
    for (id f in self.printFormatters) {
        UIPrintFormatter *myFormatter = (UIPrintFormatter *)f;

        // Top inset is only used if we want a different inset for the first page and we don't.
        // The bottom inset is never used by a viewFormatter.
        myFormatter.contentInsets = UIEdgeInsetsMake(0, leftInset, 0, rightInset);

        // Just to be sure, never allow the content to go past our minimum margins for the content area.
        myFormatter.maximumContentWidth = self.paperRect.size.width - 2*MIN_MARGIN;
        myFormatter.maximumContentHeight = self.paperRect.size.height - 2*MIN_MARGIN;

        myFormatter.startPage = startPage;
        startPage = myFormatter.startPage + myFormatter.pageCount;
    }

    // Let the superclass calculate the total number of pages
    return [super numberOfPages];
}

I still don't know if there is anyway to APPEND the printable content of both htmlFormatter and listHtmlFormatter (using this approach). e.g. rather than using a new page for listHtmlFormatter, continue printing from where htmlFormatter ended.

于 2011-05-10T08:06:41.067 に答える