我一直在尝试让它工作，而不是先将它加载到 Web 视图上并从中获取 absoluteString，以便我可以下载 URL。我尝试了许多 shortURL 解决方案，但它们从未完全加载 URL。他们总是给我一个不是最终网址的网址，也不是 PDF 网址。任何帮助都会很棒。我正在尝试在应用程序首次打开或检查更新时下载 PDF，但当时它只获取短 url，我必须等到调用 web 视图才能获取完整的 url 才能下载PDF 占了上风。
【问题讨论】：
标签： objective-c pdf redirect download short-url
这是一种使用 UIDocumentInteractionController 从 URL 打开 pdf 文件的方法：
- (void)openURL:(NSURL*)fileURL{
//Request the data from the URL
NSURLSession *session = [NSURLSession sharedSession];
[[session dataTaskWithURL:fileURL completionHandler:^(NSData *data, NSURLResponse *response,NSError *error){
if(!error){
//Save the document in a temporary file
NSString *filePath = [NSTemporaryDirectory() stringByAppendingPathComponent:[response suggestedFilename]];
[data writeToFile:filePath atomically:YES];
//Open it with the Document Interaction Controller
_docController = [UIDocumentInteractionController interactionControllerWithURL:[NSURL fileURLWithPath:filePath]];
_docController.delegate = self;
_docController.UTI = @"com.adobe.pdf";
[_docController presentOpenInMenuFromRect:CGRectZero inView:self.view animated:YES];
}
}] resume];
}
还有 myViewController.h：
@interface myViewController : UIViewController <UIDocumentInteractionControllerDelegate>
@property UIDocumentInteractionController *docController;
【讨论】：
尝试使用afnetworking将pdf文件下载到服务器
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:[NSURL URLWithString:@"https://letuscsolutions.files.wordpress.com/2015/07/five-point-someone-chetan-bhagat_ebook.pdf"]];
[request setTimeoutInterval:120];
AFHTTPRequestOperation *operation = [[AFHTTPRequestOperation alloc] initWithRequest:request];
NSString *pdfName = @"2.zip";
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *path = [[paths objectAtIndex:0] stringByAppendingPathComponent:pdfName];
operation.outputStream = [NSOutputStream outputStreamToFileAtPath:path append:NO];
[operation setDownloadProgressBlock:^(NSUInteger bytesRead, long long totalBytesRead, long long totalBytesExpectedToRead) {
};
dispatch_async(dispatch_get_main_queue(), ^{
NSLog(@"Download = %f", (float)totalBytesRead / totalBytesExpectedToRead);
NSLog(@"total bytesread%f",(float)totalBytesRead );
NSLog(@"total bytesexpected%lld",totalBytesExpectedToRead );
});
}];
[operation setCompletionBlockWithSuccess:^(AFHTTPRequestOperation *operation, id responseObject) {
NSLog(@"Successfully downloaded file to %@", path);
} failure:^(AFHTTPRequestOperation *operation, NSError *error) {
NSLog(@"Error: %@", error);
}];
[operation start];
【讨论】：
请查看AppleDocs 处理重定向请求。
【讨论】：
您下载 PDF，就像下载任何其他文件一样。
- (void)startDownloadingURL:sender
{
// Create the request.
NSURLRequest *theRequest = [NSURLRequest requestWithURL:[NSURL URLWithString:@"http://www.apple.com/index.html"]
cachePolicy:NSURLRequestUseProtocolCachePolicy
timeoutInterval:60.0];
// Create the download with the request and start loading the data.
NSURLDownload *theDownload = [[NSURLDownload alloc] initWithRequest:theRequest delegate:self];
if (!theDownload) {
// Inform the user that the download failed.
}
}
- (void)download:(NSURLDownload *)download decideDestinationWithSuggestedFilename:(NSString *)filename
{
NSString *destinationFilename;
NSString *homeDirectory = NSHomeDirectory();
destinationFilename = [[homeDirectory stringByAppendingPathComponent:@"Desktop"]
stringByAppendingPathComponent:filename];
[download setDestination:destinationFilename allowOverwrite:NO];
}
- (void)download:(NSURLDownload *)download didFailWithError:(NSError *)error
{
// Dispose of any references to the download object
// that your app might keep.
...
// Inform the user.
NSLog(@"Download failed! Error - %@ %@",
[error localizedDescription],
[[error userInfo] objectForKey:NSURLErrorFailingURLStringErrorKey]);
}
- (void)downloadDidFinish:(NSURLDownload *)download
{
// Dispose of any references to the download object
// that your app might keep.
...
// Do something with the data.
NSLog(@"%@",@"downloadDidFinish");
}
【讨论】：