从iOS中的pdf文档中读取文本和图像

我在我的iPad应用程序中显示本地存储的pdf。这是代码：

I'm displaying locally stored pdf in my iPad application. Here's the code:

NSString *path = [[NSBundle mainBundle] pathForResource:@"About Downloads" ofType:@"pdf"];
NSURL *targetURL = [NSURL fileURLWithPath:path];
NSURLRequest *request = [NSURLRequest requestWithURL:targetURL];
[pdfWebView loadRequest:request];

现在，默认情况下，您无法复制由PDF呈现的PDF中的文本或图像UIWebView的。有没有办法让用户从pdf中复制文本和/或图像？

Now, by default, you can't copy text or images from the PDF which is rendered by the UIWebView. Is there a way to let users copy text and/or images out of pdf?

我不熟悉CATitledLayer，所以我只是想知道在这种情况下它是否有帮助吗？

I'm not familiar with CATitledLayer, so i'm just wondering if it can help in this case?