iOS WebView重定向新开界面问题

这个问题困扰我好久了。终于搞好了。不容易啊。
首先介绍下这个问题，iOS上WebView 如果想更贴近native，就要加载新URL的时候新开个界面，但是如果加载的链接有重定向的话，就会在中间开一个空白的界面，这个好烦。然后就是解决这个问题，采用了很多办法。重定向的response的code是301，所以就向这个方向努力。首先在网上找到了一个方法。 原连接：http://blog.csdn.net/sheldongreen/article/details/7977802#

- (NSURLRequest *)connection:(NSURLConnection *)connection willSendRequest:(NSURLRequest *)request redirectResponse:(NSURLResponse *)response 

- (void)viewDidLoad {  
    [super viewDidLoad];  

    NSURL *url = [NSURL URLWithString:@"http://www.google.com"];  
    NSURLRequest *request = [NSURLRequest requestWithURL:url];  
    NSURLConnection *connection = [[NSURLConnection alloc] initWithRequest:request delegate:self];  

}  
- (NSURLRequest *)connection:(NSURLConnection *)connection willSendRequest:(NSURLRequest *)request redirectResponse:(NSURLResponse *)response {  

    NSLog(@"will send request\n%@", [request URL]);  
    NSLog(@"redirect response\n%@", [response URL]);  

    return request;  
}  

这种最终没试过，但是运行起来是

====will send request====  
http://www.google.com/  
====redirect response====  
(null)  


====will send request====  
http://www.google.com.hk/url?sa=p&hl=zh-CN&pref=hkredirect&pval=yes&q=http://www.google.com.hk/&ust=1347589441099727&usg=AFQjCNEsBYcrlh_jqpBWRwsc0NpBj2_lFg  
====redirect response====  
http://www.google.com/  


====will send request====  
http://www.google.com.hk/  
====redirect response====  
http://www.google.com.hk/url?sa=p&hl=zh-CN&pref=hkredirect&pval=yes&q=http://www.google.com.hk/&ust=1347589441099727&usg=AFQjCNEsBYcrlh_jqpBWRwsc0NpBj2_lFg 

但是这种不确定是重定向还是界面内跳转，而且新开界面不太好做(有兴趣的可以试试)。
pass掉

然后朋友介绍了第二种方法，在http://stackoverflow.com上找到的。附上原连接http://stackoverflow.com/questions/13505889/how-to-get-redirected-url。

-(void)webViewDidStartLoad:(UIWebView *)webView
{
    NSURL *url = [webView.request mainDocumentURL];
    NSLog(@"The Redirected URL is: %@", url);
}

依然是同上的问题。 pass掉。

终于，还是找到第三个方法。http://stackoverflow.com/questions/1061364/how-do-i-get-the-last-http-status-code-from-a-uiwebview
这个的原理是它的原理是先请求 然后用webview加载

    - (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType{
    if (navigationType != UIWebViewNavigationTypeOther) {
        self.loadedURL = request.URL.absoluteString;
    }
    if (!isLoad && [request.URL.absoluteString isEqualToString:loadedURL]) {
        [NSURLConnection sendAsynchronousRequest:request queue:[NSOperationQueue mainQueue] completionHandler:^(NSURLResponse *response, NSData *data, NSError *connectionError) {
            if (connectionError || ([response respondsToSelector:@selector(statusCode)] && [((NSHTTPURLResponse *)response) statusCode] != 200 && [((NSHTTPURLResponse *)response) statusCode] != 302)) {
                //Show error message
                [self showErrorMessage];
            }else {
                isLoad = YES;
                [self showPage:absoluteString query:nil];
            }
        }];
        return NO;
    }
    isLoad = NO;
    return YES;
}

//新开界面
-(void)showPage:(NSString *)url query:(NSString *)query
{
    NSString * newUrl = [NSString stringWithFormat:@"%@", url];

    if (query) {
        newUrl = [NSString stringWithFormat:@"%@?%@", url,query];
    }
    JFWebViewController *webView = [[JFWebViewController alloc]init];
    webView.webURL = newUrl;
    [self.navigationController pushViewController:webView animated:YES];
}

- (void)viewWillAppear:(BOOL)animated
{
    _isLoad = NO;
    [super viewWillAppear:animated];
}