Cullen SUN Cullen SUN - 3 months ago 58
iOS Question

How to Convert UIView to PDF within iOS?

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.

Answer

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

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