White lines when creating PDF from HTML (webview)

Question

I've tried to create PDF from HTML (webview). I did it. But, the problem i'm facing badly is i'm getting 1 vertical & 1 horizontal line on each page. As i attached in this link.

Click for image Zoom it if u can't see the lines.

I've tried this code

// 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, webView.bounds, nil);
    UIGraphicsBeginPDFPage();
    CGContextRef pdfContext = UIGraphicsGetCurrentContext();


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

    [webView.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:@"tmp.pdf"];

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


        // Creates a mutable data object for updating with binary data, like a byte array
    NSString *heightStr = [webView stringByEvaluatingJavaScriptFromString:@"document.body.scrollHeight;"];

    int height = [heightStr intValue];
    //  CGRect screenRect = [[UIScreen mainScreen] bounds];
    //  CGFloat screenHeight = (self.contentWebView.hidden)?screenRect.size.width:screenRect.size.height;
    CGFloat screenHeight = webView.bounds.size.height;
    int pages = ceil(height / screenHeight);

    UIGraphicsBeginPDFContextToData(pdfData, webView.bounds, nil);
    CGRect frame = [webView frame];
    for (int i = 0; i < pages; i++) {
        // Check to screenHeight if page draws more than the height of the UIWebView
        if ((i+1) * screenHeight  > height) {
            CGRect f = [webView frame];
            f.size.height -= (((i+1) * screenHeight) - height);
            [webView setFrame: f];
        }

        UIGraphicsBeginPDFPage();
        CGContextRef currentContext = UIGraphicsGetCurrentContext();
        //CGContextTranslateCTM(currentContext, 72, 72); // Translate for 1" margins


        [[[webView subviews] lastObject] setContentOffset:CGPointMake(0, screenHeight * i) animated:NO];
        [webView.layer renderInContext:currentContext];
    }

    UIGraphicsEndPDFContext();

    // instructs the mutable data object to write its context to a file on disk
    [pdfData writeToFile:self.PDFpath atomically:YES];
    [webView setFrame:frame];

Any one have idea about this ?

Answer 1

Okay, i got it. It wasn't lines the code i was using above makes 4 parts of each page from UIWebView and print them to PDF as image. So it was the gap between those parts.