我有一个应用程序，在其中我可以下载PDF并将其存储在iPhone中。在iOS 7上它完美地工作（我目前运行的是iOS 8），而在iOS 8上运行应用程序时，webView仅保持空白。我不知道出了什么问题。
#import "ISJMMisalViewController.h"
#import "SWRevealViewController.h"
@implementation ISJMMisalViewController
@synthesize activityImageView;
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:YES];
[self.webView addSubview:activityImageView];
[activityImageView startAnimating];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
NSString *resourceDocPath = [[NSString alloc] initWithString:[[[[NSBundle mainBundle] resourcePath]stringByDeletingLastPathComponent] stringByAppendingPathComponent:@"Documents"]];
NSString *filePath = [resourceDocPath stringByAppendingPathComponent:@"misalLocal.pdf"];
//Now create Request for the file that was saved in your documents folder
NSURL *url = [NSURL fileURLWithPath:filePath];
NSURLRequest *requestObj = [NSURLRequest requestWithURL:url];
dispatch_async(dispatch_get_main_queue(), ^{
[self.webView setUserInteractionEnabled:YES];
[self.webView setDelegate:self];
[self.webView loadRequest:requestObj];
[self.webView setScalesPageToFit:YES];
[activityImageView stopAnimating];
[activityImageView removeFromSuperview];
});
});
}
- (void)viewDidLoad {
[super viewDidLoad];
[self.view addGestureRecognizer:self.revealViewController.panGestureRecognizer];
UIImage *image = [UIImage imageNamed: @"NavBarImage.png"];
UIImageView *imageView = [[UIImageView alloc] initWithImage: image];
self.navigationItem.titleView = imageView;
_sidebarButton.target = self.revealViewController;
_sidebarButton.action = @selector(revealToggle:);
//Create the first status image and the indicator view
UIImage *statusImage = [UIImage imageNamed:@"1.png"];
activityImageView = [[UIImageView alloc] initWithImage:statusImage];
//Add more images which will be used for the animation
activityImageView.animationImages = [NSArray arrayWithObjects:
[UIImage imageNamed:@"1.png"],
[UIImage imageNamed:@"2.png"],
[UIImage imageNamed:@"3.png"],
[UIImage imageNamed:@"4.png"],
[UIImage imageNamed:@"5.png"],
[UIImage imageNamed:@"6.png"],
[UIImage imageNamed:@"7.png"],
[UIImage imageNamed:@"8.png"],
[UIImage imageNamed:@"9.png"],
nil];
//Set the duration of the animation (play with it
//until it looks nice for you)
activityImageView.animationDuration = 0.7;
//Position the activity image view somewhere in
//the middle of your current view
activityImageView.frame = CGRectMake(self.view.frame.size.width/2 - 50, self.view.frame.size.height/2 - 100, 100, 100);
UITapGestureRecognizer *gesture = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(toggleNavBar:)];
[self. webView addGestureRecognizer:gesture];
if (!self.webView) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Sin conexión"
message:@"No fue posible la descarga de datos debido a que no se pudo conectar con el servidor"
delegate: nil
cancelButtonTitle: @"OK"
otherButtonTitles: nil];
[alert show];
}
}
- (IBAction)actualizar:(id)sender {
[self.webView addSubview:activityImageView];
[activityImageView startAnimating];
dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
NSData *pdfData = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:@"http://isjm.weebly.com/uploads/2/5/3/6/25368636/misal.pdf"]];
NSString *resourceDocPath = [[NSString alloc] initWithString:[[[[NSBundle mainBundle] resourcePath]stringByDeletingLastPathComponent] stringByAppendingPathComponent:@"Documents"]];
NSString *filePath = [resourceDocPath stringByAppendingPathComponent:@"misalLocal.pdf"];
[pdfData writeToFile:filePath atomically:YES];
NSURL *url = [NSURL fileURLWithPath:filePath];
NSURLRequest *requestObj = [NSURLRequest requestWithURL:url];
dispatch_async(dispatch_get_main_queue(), ^{
[self.webView setUserInteractionEnabled:YES];
[self.webView setDelegate:self];
[self.webView loadRequest:requestObj];
[self.webView setScalesPageToFit:YES];
[activityImageView stopAnimating];
[activityImageView removeFromSuperview];
if (!self.webView) {
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Sin conexión"
message:@"No fue posible la descarga de datos debido a que no se pudo conectar con el servidor"
delegate: nil
cancelButtonTitle: @"OK"
otherButtonTitles: nil];
[alert show];
}
});
});
}
- (void)toggleNavBar:(UITapGestureRecognizer *)gesture {
BOOL barsHidden = self.navigationController.navigationBar.hidden;
[self.navigationController setNavigationBarHidden:!barsHidden animated:YES];
}
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
return YES;
}
@end