UIPrintInteractionController返回UIPrintUnknownImageFormatError

Question

我想打印PDF文件通過NSURLConnection的下載這樣

UIPrintInteractionController *pic = [UIPrintInteractionController sharedPrintController]; 
    NSData *PDFData = urlConnection.receivedData; 
    if (pic && [UIPrintInteractionController canPrintData:PDFData]) { 
     pic.printingItem = PDFData; 
     ... 
     [pic presentAnimated:YES completionHandler:completionHandler]; 
    } 

，我收到UIPrintUnknownImageFormatError在completionHandler儘管PDF是良好的，由任何PDF查看器打開。它有什麼問題？

Answer 1

這一招幫助：

[receivedData writeToFile:filePath atomically:YES]; 
    NSData *PDFData = [NSData dataWithContentsOfFile:filePath];