活动指示器不根据 UIWebView 是否正在加载而显示

Question

抱歉，如果这是一件简单的事情。基本上，这是我的代码：

MainViewController.h：

#import "FlipsideViewController.h"

@interface MainViewController : UIViewController <UIWebViewDelegate, FlipsideViewControllerDelegate> {
    IBOutlet UIWebView *webView;
    IBOutlet UIActivityIndicatorView *spinner;
}

- (IBAction)showInfo;

@property(nonatomic,retain) UIWebView *webView;
@property(nonatomic,retain) UIActivityIndicatorView *spinner;

@end

MainViewController.m：

#import "MainViewController.h"
#import "MainView.h"

@implementation MainViewController

@synthesize webView;
@synthesize spinner;

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil {
    if (self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]) {
        // Custom initialization
    }
    return self;
}

 - (void)viewDidLoad {

     NSURL *siteURL;
     NSString *siteURLString;

     siteURLString=[[NSString alloc] initWithString:@"http://www.site.com"];

     siteURL=[[NSURL alloc] initWithString:siteURLString];

     [webView loadRequest:[NSURLRequest requestWithURL:siteURL]];

     [siteURL release];
     [siteURLString release];

 [super viewDidLoad];
 }

- (void)flipsideViewControllerDidFinish:(FlipsideViewController *)controller {

    [self dismissModalViewControllerAnimated:YES];
}

- (void)webViewDidFinishLoad:(UIWebView *)webView {
    [spinner stopAnimating];  
    spinner.hidden=FALSE;
    NSLog(@"viewDidFinishLoad went through nicely");
}

- (void)webViewDidStartLoad:(UIWebView *)webView {     
    [spinner startAnimating];     
    spinner.hidden=FALSE;
    NSLog(@"viewDidStartLoad seems to be working");
}

- (IBAction)showInfo {    

    FlipsideViewController *controller = [[FlipsideViewController alloc] initWithNibName:@"FlipsideView" bundle:nil];
    controller.delegate = self;

    controller.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
    [self presentModalViewController:controller animated:YES];

    [controller release];
}

- (void)dealloc {
    [spinner release];
    [webView release];
    [super dealloc];
}


@end

不幸的是，没有任何内容写入我的日志，并且由于某种原因UIActivityIndi​​cator 似乎从未出现过。这里出了什么问题？

谢谢大家

杰克

Answer 1

您需要设置 UIWebView 委托。您实现了该协议，但您从未告诉 UIWebView 该类是委托，因此这些方法永远不会被调用。

webView.delegate = self;

另外，您可能还想查看这个问题/答案关于如何实现 UIWebViewDelegate 方法。

Answer 2

- webViewDidFinishLoad: 在成功从相关 URL 加载内容后发送到 Web 视图的委托。您是否通过在 Safari 中检查该 URL 来确认该 URL 是否有效？您是否仔细检查过您的代表连接？