使用Cocoa-Touch在iOS中将html文件转换为PDF文档 [英] Convert html file to PDF Document in iOS using Cocoa-Touch

问题描述

我想将iPhone上的本地html文件转换为PDF文档。我使用下面的代码，我在网上发现从图片生成PDF文件，我试图用html文件替换图像，但它失败。我非常感谢您的帮助。
提前感谢，

I want to convert local html file on iPhone to PDF document. I have used the following code I found online to generate PDF file from Picture, I tried to replace the image with the html file but it failed. I would very much appreciate your help. Thanks in advance,

// Our method to create a PDF file natively on the iPhone
// This method takes two parameters, a CGRect for size and
// a const char, which will be the name of our pdf file
void CreatePDFFile (CGRect pageRect, const char *filename) {

    // This code block sets up our PDF Context so that we can draw to it
    CGContextRef pdfContext;
    CFStringRef path;
    CFURLRef url;
    CFMutableDictionaryRef myDictionary = NULL;
    // Create a CFString from the filename we provide to this method when we call it
    path = CFStringCreateWithCString (NULL, filename,
                                      kCFStringEncodingUTF8);
    // Create a CFURL using the CFString we just defined
    url = CFURLCreateWithFileSystemPath (NULL, path,
                                         kCFURLPOSIXPathStyle, 0);
    CFRelease (path);
    // This dictionary contains extra options mostly for 'signing' the PDF
    myDictionary = CFDictionaryCreateMutable(NULL, 0,
                                             &kCFTypeDictionaryKeyCallBacks,
                                             &kCFTypeDictionaryValueCallBacks);
    CFDictionarySetValue(myDictionary, kCGPDFContextTitle, CFSTR("My PDF File"));
    CFDictionarySetValue(myDictionary, kCGPDFContextCreator, CFSTR("My Name"));
    // Create our PDF Context with the CFURL, the CGRect we provide, and the above defined dictionary
    pdfContext = CGPDFContextCreateWithURL (url, &pageRect, myDictionary);
    // Cleanup our mess
    CFRelease(myDictionary);
    CFRelease(url);
    // Done creating our PDF Context, now it's time to draw to it

    // Starts our first page
    CGContextBeginPage (pdfContext, &pageRect);

    // Draws a black rectangle around the page inset by 50 on all sides
    CGContextStrokeRect(pdfContext, CGRectMake(50, 50, pageRect.size.width - 100, pageRect.size.height - 100));

    // This code block will create an image that we then draw to the page
    const char *picture = "Picture";
    CGImageRef image;
    CGDataProviderRef provider;
    CFStringRef picturePath;
    CFURLRef pictureURL;

    picturePath = CFStringCreateWithCString (NULL, picture,
                                      kCFStringEncodingUTF8);
    pictureURL = CFBundleCopyResourceURL(CFBundleGetMainBundle(), picturePath, CFSTR("png"), NULL);
    CFRelease(picturePath);
    provider = CGDataProviderCreateWithURL (pictureURL);
    CFRelease (pictureURL);
    image = CGImageCreateWithPNGDataProvider (provider, NULL, true, kCGRenderingIntentDefault);
    CGDataProviderRelease (provider);
    CGContextDrawImage (pdfContext, CGRectMake(200, 200, 207, 385),image);
    CGImageRelease (image);


    // End image code

    // Adding some text on top of the image we just added
    CGContextSelectFont (pdfContext, "Helvetica", 16, kCGEncodingMacRoman);
    CGContextSetTextDrawingMode (pdfContext, kCGTextFill);
    CGContextSetRGBFillColor (pdfContext, 0, 0, 0, 1);
    const char *text = "Hello World!";
    CGContextShowTextAtPoint (pdfContext, 260, 390, text, strlen(text));
    // End text

    // We are done drawing to this page, let's end it
    // We could add as many pages as we wanted using CGContextBeginPage/CGContextEndPage
    CGContextEndPage (pdfContext);

    // We are done with our context now, so we release it
    CGContextRelease (pdfContext);
}

- (IBAction)createPDF:(id)sender {
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *saveDirectory = [paths objectAtIndex:0];
    NSString *saveFileName = @"myPDF.pdf";
    NSString *newFilePath = [saveDirectory stringByAppendingPathComponent:saveFileName];
    const char *filename = [newFilePath UTF8String];
    CreatePDFFile(CGRectMake(0, 0, 612, 792),filename);
}

推荐答案

您需要：

• 创建Webview并加载HTML。


• 执行Webview Capture。 / li>
  
• 将其转换为PDF文件。

必须完成第二步一旦您的webview内容加载
对于此捕获，您可以在如何截取UIView的屏幕截图？
然后使用此上下文转换为PDF文件。

The second step (webview capture) have to be done once your webview content is loaded For this capture you can find sample as in How Do I Take a Screen Shot of a UIView? Then you use this context to convert into PDF file.

对于webview，你不需要显示它，只需创建它，而不添加在屏幕上的视图。

For the webview you don't need to show it, just create it without adding the view on screen.

编辑：
其他细节， height可以计算webview内容高度并更改您的webview框架

Other detail, for webview height you can calculate the webview content height and change your webview frame

- (void)webViewDidFinishLoad:(UIWebView *)theWebView {
    NSUInteger contentHeight = [[theWebView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:@"document.body.scrollHeight;"]] intValue];
    NSUInteger contentWidth = [[theWebView stringByEvaluatingJavaScriptFromString:[NSString stringWithFormat:@"document.body.scrollWidth;"]] intValue];
    [theWebView setFrame:CGRectMake(0, 0, contentWidth, contentHeight)];
}

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