How to Convert UIView to PDF within iOS?

问题:

There are a lot of resources about how to display a PDF in an App\'s UIView. What I am working on now is to create a PDF from UIViews.

For example, I have a UIView, with subviews like Textviews, UILabels, UIImages, so how can I convert a big UIView as a whole including all its subviews and subsubviews to a PDF?

I have checked Apple\'s iOS reference. However, it only talks about writing pieces of text/image to a PDF file.

The problem I am facing is that the content I want to write to a file as PDF is a lot. If I write them to the PDF piece by piece, it is going to be huge work to do. That\'s why I am looking for a way to write UIViews to PDFs or even bitmaps.

I have tried the source code I copied from other Q/A within Stack Overflow. But it only gives me a blank PDF with the UIView bounds size.

-(void)createPDFfromUIView:(UIView*)aView saveToDocumentsWithFileName:(NSString*)aFilename
{
    // Creates a mutable data object for updating with binary data, like a byte array
    NSMutableData *pdfData = [NSMutableData data];

    // Points the pdf converter to the mutable data object and to the UIView to be converted
    UIGraphicsBeginPDFContextToData(pdfData, aView.bounds, nil);
    UIGraphicsBeginPDFPage();

    // draws rect to the view and thus this is captured by UIGraphicsBeginPDFContextToData
    [aView drawRect:aView.bounds];

    // remove PDF rendering context
    UIGraphicsEndPDFContext();

    // Retrieves the document directories from the iOS device
    NSArray* documentDirectories = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES);

    NSString* documentDirectory = [documentDirectories objectAtIndex:0];
    NSString* documentDirectoryFilename = [documentDirectory stringByAppendingPathComponent:aFilename];

    // instructs the mutable data object to write its context to a file on disk
    [pdfData writeToFile:documentDirectoryFilename atomically:YES];
    NSLog(@\"documentDirectoryFileName: %@\",documentDirectoryFilename);
}

Please help. Thanks.

回答1:

Note that the following method creates just a bitmap of the view; it does not create actual typography.

(void)createPDFfromUIView:(UIView*)aView saveToDocumentsWithFileName:(NSString*)aFilename
{
    // Creates a mutable data object for updating with binary data, like a byte array
    NSMutableData *pdfData = [NSMutableData data];

    // Points the pdf converter to the mutable data object and to the UIView to be converted
    UIGraphicsBeginPDFContextToData(pdfData, aView.bounds, nil);
    UIGraphicsBeginPDFPage();
    CGContextRef pdfContext = UIGraphicsGetCurrentContext();


    // draws rect to the view and thus this is captured by UIGraphicsBeginPDFContextToData

    [aView.layer renderInContext:pdfContext];

    // remove PDF rendering context
    UIGraphicsEndPDFContext();

    // Retrieves the document directories from the iOS device
    NSArray* documentDirectories = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES);

    NSString* documentDirectory = [documentDirectories objectAtIndex:0];
    NSString* documentDirectoryFilename = [documentDirectory stringByAppendingPathComponent:aFilename];

    // instructs the mutable data object to write its context to a file on disk
    [pdfData writeToFile:documentDirectoryFilename atomically:YES];
    NSLog(@\"documentDirectoryFileName: %@\",documentDirectoryFilename);
}

Also make sure you import: QuartzCore/QuartzCore.h

回答2:

Additionally, if anyone is interested, here is the Swift 3 code:

func createPdfFromView(aView: UIView, saveToDocumentsWithFileName fileName: String)
{
    let pdfData = NSMutableData()
    UIGraphicsBeginPDFContextToData(pdfData, aView.bounds, nil)
    UIGraphicsBeginPDFPage()

    guard let pdfContext = UIGraphicsGetCurrentContext() else { return }

    aView.layer.render(in: pdfContext)
    UIGraphicsEndPDFContext()

    if let documentDirectories = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first {
        let documentsFileName = documentDirectories + \"/\" + fileName
        debugPrint(documentsFileName)
        pdfData.write(toFile: documentsFileName, atomically: true)
    }
}

回答3:

If someone is interested, here\'s Swift 2.1 code:

    func createPdfFromView(aView: UIView, saveToDocumentsWithFileName fileName: String)
    {
        let pdfData = NSMutableData()
        UIGraphicsBeginPDFContextToData(pdfData, aView.bounds, nil)
        UIGraphicsBeginPDFPage()

        guard let pdfContext = UIGraphicsGetCurrentContext() else { return }

        aView.layer.renderInContext(pdfContext)
        UIGraphicsEndPDFContext()

        if let documentDirectories = NSSearchPathForDirectoriesInDomains(.DocumentDirectory, .UserDomainMask, true).first {
            let documentsFileName = documentDirectories + \"/\" + fileName
            debugPrint(documentsFileName)
            pdfData.writeToFile(documentsFileName, atomically: true)
        }
    }

回答4:

This will generate PDF from UIView and open print dialog, objective C. Attach - (IBAction)PrintPDF:(id)sender to your button on screen. Add #import <QuartzCore/QuartzCore.h> framework

H File

    @interface YourViewController : UIViewController <MFMailComposeViewControllerDelegate,UIPrintInteractionControllerDelegate>

    {
    UIPrintInteractionController *printController;
    }

- (IBAction)PrintPDF:(id)sender;

M File

-(void)createPDFfromUIView:(UIView*)aView saveToDocumentsWithFileName:(NSString*)aFilename

{
    NSMutableData *pdfData = [NSMutableData data];

    UIGraphicsBeginPDFContextToData(pdfData, aView.bounds, nil);
    UIGraphicsBeginPDFPage();
    CGContextRef pdfContext = UIGraphicsGetCurrentContext();


    [aView.layer renderInContext:pdfContext];
    UIGraphicsEndPDFContext();

    NSArray* documentDirectories = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES);

    NSString* documentDirectory = [documentDirectories objectAtIndex:0];
    NSString* documentDirectoryFilename = [documentDirectory stringByAppendingPathComponent:aFilename];
    NSString *file = [documentDirectory stringByAppendingPathComponent:@\"yourPDF.pdf\"];
    NSURL *urlPdf = [NSURL fileURLWithPath: file];

    [pdfData writeToFile:documentDirectoryFilename atomically:YES];
    NSLog(@\"documentDirectoryFileName: %@\",documentDirectoryFilename);

}


- (IBAction)PrintPDF:(id)sender
{
    [self createPDFfromUIView:self.view saveToDocumentsWithFileName:@\"yourPDF.pdf\"];

    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *path = [documentsDirectory stringByAppendingPathComponent:@\"yourPDF.pdf\"];
    NSData *myData = [NSData dataWithContentsOfFile: path];

    UIPrintInteractionController *pic = [UIPrintInteractionController sharedPrintController];
    if(pic && [UIPrintInteractionController canPrintData: myData] ) {

        pic.delegate = self;

        UIPrintInfo *printInfo = [UIPrintInfo printInfo];
        printInfo.outputType = UIPrintInfoOutputGeneral;
        printInfo.jobName = [path lastPathComponent];
        printInfo.duplex = UIPrintInfoDuplexLongEdge;
        pic.printInfo = printInfo;
        pic.showsPageRange = YES;
        pic.printingItem = myData;

        void (^completionHandler)(UIPrintInteractionController *, BOOL, NSError *) = ^(UIPrintInteractionController *pic, BOOL completed, NSError *error) {
            //self.content = nil;
            if(!completed && error){

                NSLog(@\"Print Error: %@\", error);
            }
        };

        [pic presentAnimated:YES completionHandler:completionHandler];

    }

}

回答5:

I don\'t know why, but casilic\'s answer gives me blank screen on iOS6.1. The code below works.

-(NSMutableData *)createPDFDatafromUIView:(UIView*)aView 
{
    // Creates a mutable data object for updating with binary data, like a byte array
    NSMutableData *pdfData = [NSMutableData data];

    // Points the pdf converter to the mutable data object and to the UIView to be converted
    UIGraphicsBeginPDFContextToData(pdfData, aView.bounds, nil);
    UIGraphicsBeginPDFPage();
    CGContextRef pdfContext = UIGraphicsGetCurrentContext();


    // draws rect to the view and thus this is captured by UIGraphicsBeginPDFContextToData

    [aView.layer renderInContext:pdfContext];

    // remove PDF rendering context
    UIGraphicsEndPDFContext();

    return pdfData;
}


-(NSString*)createPDFfromUIView:(UIView*)aView saveToDocumentsWithFileName:(NSString*)aFilename
{
    // Creates a mutable data object for updating with binary data, like a byte array
    NSMutableData *pdfData = [self createPDFDatafromUIView:aView];

    // Retrieves the document directories from the iOS device
    NSArray* documentDirectories = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES);

    NSString* documentDirectory = [documentDirectories objectAtIndex:0];
    NSString* documentDirectoryFilename = [documentDirectory stringByAppendingPathComponent:aFilename];

    // instructs the mutable data object to write its context to a file on disk
    [pdfData writeToFile:documentDirectoryFilename atomically:YES];
    NSLog(@\"documentDirectoryFileName: %@\",documentDirectoryFilename);
    return documentDirectoryFilename;
}