我的应用程序在表格视图中显示来自 RSS 提要的文章，然后当您选择一行时，打开 Web 视图控制器以显示文章。我正在尝试添加加载指示器。如果我选择一行，指示器将短暂显示，然后在页面完全加载之前消失。此外，如果我返回表格视图并选择不同的行，加载指示器永远不会出现。我正在使用一个名为 SVProgressHUD 的自定义加载指示器，它在应用程序的其他地方运行良好。我不认为这是问题所在。我究竟做错了什么？
这是我的表视图中的 didSelectRowAtIndexPath 方法：
- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
[[webViewController webView]loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"about:blank"]]];
[self.navigationController pushViewController:webViewController animated:YES];
// Grab the selected item
RSSItem *entry = [[channel items]objectAtIndex:[indexPath row]];
// Construct a URL with the link string of the item
NSURL *url = [NSURL URLWithString:[entry link]];
// Construct a request object with that URL
NSURLRequest *req = [NSURLRequest requestWithURL:url];
// Load the request into the web view
[[webViewController webView]loadRequest:req];
webViewController.hackyURL = url;
}
加载指示器在 WebViewController 的 viewDidLoad 中的这一行开始：
[SVProgressHUD showWithStatus:@"Loading"];
这是我的 WebViewController。
#import "WebViewController.h"
#import "TUSafariActivity.h"
#import "SVProgressHUD.h"
@implementation WebViewController
@synthesize webView=webView, hackyURL=hackyURL;
- (void)loadView
{
// Create an instance of UIWebView as large as the screen
CGRect screenFrame = [[UIScreen mainScreen]applicationFrame];
UIWebView *wv = [[UIWebView alloc]initWithFrame:screenFrame];
webView = wv;
NSLog(@"%@",webView.request.URL);
// Tell web view to scale web content to fit within bounds of webview
[wv setScalesPageToFit:YES];
[self setView:wv];
}
- (UIWebView *)webView
{
return (UIWebView *)[self view];
}
- (void) showMenu
{
NSURL *urlToShare = hackyURL;
NSArray *activityItems = @[urlToShare];
TUSafariActivity *activity = [[TUSafariActivity alloc] init];
__block UIActivityViewController *activityVC = [[UIActivityViewController alloc]initWithActivityItems:activityItems applicationActivities:@[activity]];
activityVC.excludedActivityTypes = @[UIActivityTypeAssignToContact, UIActivityTypePostToWeibo, UIActivityTypeSaveToCameraRoll];
[self presentViewController:activityVC animated:YES completion:^{activityVC.excludedActivityTypes = nil; activityVC = nil;}];
}
- (void)toggleBars:(UITapGestureRecognizer *)gesture
{
BOOL barsHidden = self.navigationController.navigationBar.hidden;
if (!barsHidden)
{
[[UIApplication sharedApplication] setStatusBarHidden:YES withAnimation:UIStatusBarAnimationSlide];
[self hideTabBar:self.tabBarController];
}
else if (barsHidden)
{
[[UIApplication sharedApplication] setStatusBarHidden:NO withAnimation:UIStatusBarAnimationSlide];
[self showTabBar:self.tabBarController];
}
[self.navigationController setNavigationBarHidden:!barsHidden animated:YES];
}
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view from its nib.
[SVProgressHUD showWithStatus:@"Loading"];
UIBarButtonItem *systemAction = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAction target:self action:@selector(showMenu)];
self.navigationItem.rightBarButtonItem = systemAction;
UITapGestureRecognizer *singleTap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(toggleBars:)];
[webView addGestureRecognizer:singleTap];
singleTap.delegate = self;
// self.hidesBottomBarWhenPushed = YES;
}
- (BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldRecognizeSimultaneouslyWithGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer
{
return YES;
}
- (void) hideTabBar:(UITabBarController *) tabbarcontroller
{
CGRect screenRect = [[UIScreen mainScreen] bounds];
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.5];
float fHeight = screenRect.size.height;
if( UIDeviceOrientationIsLandscape([UIApplication sharedApplication].statusBarOrientation) )
{
fHeight = screenRect.size.width;
}
for(UIView *view in tabbarcontroller.view.subviews)
{
if([view isKindOfClass:[UITabBar class]])
{
[view setFrame:CGRectMake(view.frame.origin.x, fHeight, view.frame.size.width, view.frame.size.height)];
}
else
{
[view setFrame:CGRectMake(view.frame.origin.x, view.frame.origin.y, view.frame.size.width, fHeight)];
view.backgroundColor = [UIColor blackColor];
}
}
[UIView commitAnimations];
}
- (void) showTabBar:(UITabBarController *) tabbarcontroller
{
CGRect screenRect = [[UIScreen mainScreen] bounds];
float fHeight = screenRect.size.height - 49.0;
if( UIDeviceOrientationIsLandscape([UIApplication sharedApplication].statusBarOrientation) )
{
fHeight = screenRect.size.width - 49.0;
}
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:0.5];
for(UIView *view in tabbarcontroller.view.subviews)
{
if([view isKindOfClass:[UITabBar class]])
{
[view setFrame:CGRectMake(view.frame.origin.x, fHeight, view.frame.size.width, view.frame.size.height)];
}
else
{
[view setFrame:CGRectMake(view.frame.origin.x, view.frame.origin.y, view.frame.size.width, fHeight)];
}
}
[UIView commitAnimations];
}
- (void)webViewDidFinishLoad:(UIWebView *)webView
{
//stop the activity indicator when done loading
[SVProgressHUD dismiss];
}
@end