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如何在ios应用程序中显示和编辑现有的PDF文件

发布于 2024-12-08 03:12:01 字数 210 浏览 0 评论 0原文

我不想创建新的 PDF 文件，我已经完成了，但想通过代码在 iOS 中显示和编辑现有的 pdf 文件。

这是否可能，如果可能的话我该怎么做...

更新

假设有一个文本文档pdf，我们想在该文件中输入一些其他文本并保存。那么如何通过编程来做到这一点？

请帮我解决这个问题...

提前致谢...

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离不开的别离 2024-12-15 03:12:01

我可以通过创建原始 PDF 的副本并在构建过程中对其进行修改来做到这一点。

PS：在我的解决方案中，我需要编辑新PDF的文档信息，所以我使用
执行此操作的 subject 参数。

在Swift 3中

func createPDF(on path: String?, from templateURL: URL?, with subject: String?) {
    guard let newPDFPath = path,
        let pdfURL = templateURL else { return }

    let options = [(kCGPDFContextSubject as String): subject ?? ""] as CFDictionary

    UIGraphicsBeginPDFContextToFile(newPDFPath, .zero, options as? [AnyHashable : Any])

    let templateDocument = CGPDFDocument(pdfURL as CFURL)
    let pageCount = templateDocument?.numberOfPages ?? 0

    for i in 1...pageCount {

        //get bounds of template page
        if let templatePage = templateDocument?.page(at: i) {
            let templatePageBounds = templatePage.getBoxRect(.cropBox)

            //create empty page with corresponding bounds in new document
            UIGraphicsBeginPDFPageWithInfo(templatePageBounds, nil)
            let context = UIGraphicsGetCurrentContext()

            //flip context due to different origins
            context?.translateBy(x: 0.0, y: templatePageBounds.height)
            context?.scaleBy(x: 1.0, y: -1.0)

            //copy content of template page on the corresponding page in new file
            context?.drawPDFPage(templatePage)

            //flip context back
            context?.translateBy(x: 0.0, y: templatePageBounds.height)
            context?.scaleBy(x: 1.0, y: -1.0)


            // -->>>>  Do your change here  <<<<--
            /* Here you can do any drawings */

        }
    }
    UIGraphicsEndPDFContext()
}

I was able to do this by creating a copy of the original PDF and modifying it during the build process.

PS: In my solution I needed to edit the document info of the new PDF, so I used
the subject parameter to do this.

In Swift 3

func createPDF(on path: String?, from templateURL: URL?, with subject: String?) {
    guard let newPDFPath = path,
        let pdfURL = templateURL else { return }

    let options = [(kCGPDFContextSubject as String): subject ?? ""] as CFDictionary

    UIGraphicsBeginPDFContextToFile(newPDFPath, .zero, options as? [AnyHashable : Any])

    let templateDocument = CGPDFDocument(pdfURL as CFURL)
    let pageCount = templateDocument?.numberOfPages ?? 0

    for i in 1...pageCount {

        //get bounds of template page
        if let templatePage = templateDocument?.page(at: i) {
            let templatePageBounds = templatePage.getBoxRect(.cropBox)

            //create empty page with corresponding bounds in new document
            UIGraphicsBeginPDFPageWithInfo(templatePageBounds, nil)
            let context = UIGraphicsGetCurrentContext()

            //flip context due to different origins
            context?.translateBy(x: 0.0, y: templatePageBounds.height)
            context?.scaleBy(x: 1.0, y: -1.0)

            //copy content of template page on the corresponding page in new file
            context?.drawPDFPage(templatePage)

            //flip context back
            context?.translateBy(x: 0.0, y: templatePageBounds.height)
            context?.scaleBy(x: 1.0, y: -1.0)


            // -->>>>  Do your change here  <<<<--
            /* Here you can do any drawings */

        }
    }
    UIGraphicsEndPDFContext()
}

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临走之时 2024-12-15 03:12:01

我知道这个问题已经太晚了，但我想添加我的解决方案。

我正在使用 UIGraphicsBeginPDFContextToFile 生成 PDF 文件。我从基类 UIViewController 创建了一个名为 PDFCreator 的类，因为我有两个这样的函数：

- (void) beginContextWithFile:(NSString *)filename
{
    pageSize = CGSizeMake(1024, 1424);

    UIGraphicsBeginPDFContextToFile(filename, CGRectZero, nil);

    UIGraphicsBeginPDFPageWithInfo(CGRectMake(0, 0, pageSize.width, pageSize.height), nil);

    [self createInitialPart];
}

- (void) endContext
{
    UIGraphicsEndPDFContext();
}

我在应用程序委托文件中创建了此类的对象，因为它将保留该对象直到应用程序终止（这是我的要求）。

最初，我调用 beginContextWithFile: ，它将在文档目录中创建一个 pdf 文件以及我通过调用 createInitialPart 方法添加的数据。

在稍后的某个时刻，我需要更新该文件，因此我有另一个名为 secondPart 的方法，尽管我调用它是为了将更多数据附加到该文件中。

一旦我完成了创建，我需要调用 PDFCreator 类的 endContext ，这将完成 pdf 生成，是的，我将拥有更新的文件。

这有点棘手，尽管我有要求，但我没有执行任何内存检查，我找到了解决方案:)

I know its too late for this question, however I'd like to add my solution.

I am using UIGraphicsBeginPDFContextToFile to generate a PDF file. I've created a class called PDFCreator from base class UIViewController, in that I have two functions like this:

- (void) beginContextWithFile:(NSString *)filename
{
    pageSize = CGSizeMake(1024, 1424);

    UIGraphicsBeginPDFContextToFile(filename, CGRectZero, nil);

    UIGraphicsBeginPDFPageWithInfo(CGRectMake(0, 0, pageSize.width, pageSize.height), nil);

    [self createInitialPart];
}

- (void) endContext
{
    UIGraphicsEndPDFContext();
}

I've created an object of this class in the app delegate file, as it will retain the object until the app terminates (as was my requirement).

Initially, I am calling beginContextWithFile: and it will create a pdf file in the document directory along with data I am adding through a call to the createInitialPart method.

At some point later I need to update that file, so I have another method named secondPart though I called it for some more data to append to that file.

Once I fill I've done with the creation, I need to call endContext of PDFCreator class, that will complete the pdf generation and yes, I will have the updated file.

This is little tricky and I didn't perform any memory checks though I had the requirement, I found the solution :)

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