如何在ios应用程序中显示和编辑现有PDF文件

Question

I do not want to create new PDF file,that I had already done but want to show and edit existing pdf file in iOS through code..

Is this possible or not and if possible than how can I do this...

Update

Suppose there will be text document pdf and we want to enter some other text in that file and save it..so how to do this by programming?

Please help me to solve this problem...

Thanks in advance...

Answer 1

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 :)

Answer 2

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()
}

Answer 3

You can use Quartz2D to manipulate your PDF, open them, make transformation and so on.

Check out the official documentation

Update :

Create your pdf context as explained in the documentation, then you just have to write text :

http://developer.apple.com/library/ios/#documentation/graphicsimaging/conceptual/drawingwithquartz2d/dq_text/dq_text.html#//apple_ref/doc/uid/TP30001066-CH213-TPXREF101