从WebView获取URL以在Safari中打开

Question

我有一个应用程序读取RSS源，当选择表视图中的行时，它会在Web视图中打开文章。我想要一个按钮来显示一个操作表，其中包含一个在Safari中打开URL的选项。我正在使用操作表，因为我将在不久的将来为它添加更多按钮。

WebViewController.m

//
//  WebViewController.m
//  KFBNewsroom
//
//  Created by KFB on 10/16/12.
//  Copyright (c) 2012 com.kfb. All rights reserved.
//

#import "WebViewController.h"

@implementation WebViewController

- (void)loadView
{
    // Create an instance of UIWebView as large as the screen
    CGRect screenFrame = [[UIScreen mainScreen]applicationFrame];
    UIWebView *wv = [[UIWebView alloc]initWithFrame:screenFrame];
    // 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];
}


@end

ListViewController.m

//
//  ListViewController.m
//  KFBNewsroom
//
//  Created by KFB on 10/16/12.
//  Copyright (c) 2012 com.kfb. All rights reserved.
//

#import "ListViewController.h"
#import "RSSChannel.h"
#import "RSSItem.h"
#import "WebViewController.h"

@implementation ListViewController
@synthesize webViewController;

- (void)viewDidLoad
{
    self.title = @"Public Affairs";
    UIRefreshControl *refresh = [[UIRefreshControl alloc] init];
    refresh.attributedTitle = [[NSAttributedString alloc] initWithString:@"Pull to Refresh"];
    [refresh addTarget:self action:@selector(refreshView:)forControlEvents:UIControlEventValueChanged];
    self.refreshControl = refresh;
}

- (void)parser:(NSXMLParser *)parser didStartElement:(NSString *)elementName namespaceURI:(NSString *)namespaceURI qualifiedName:(NSString *)qName attributes:(NSDictionary *)attributeDict
{
    NSLog(@"%@ found a %@ element", self, elementName);
    if ([elementName isEqual:@"channel"])
    {
        // If the parser saw a channel, create new instance, store in our ivar
        channel = [[RSSChannel alloc]init];

        // Give the channel object a pointer back to ourselves for later
        [channel setParentParserDelegate:self];

        // Set the parser's delegate to the channel object
        [parser setDelegate:channel];
    }
}

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    // return 0;
    NSLog(@"channel items %d", [[channel items]count]);
    return [[channel items]count];
}

- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    // return nil;

    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:@"UITableViewCell"];
    if (cell == nil)
    {
        cell = [[UITableViewCell alloc]initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"UITableViewCell"];
        cell.textLabel.font=[UIFont systemFontOfSize:16.0];
    }
    RSSItem *item = [[channel items]objectAtIndex:[indexPath row]];
    [[cell textLabel]setText:[item title]];

    return cell;
}

- (void)fetchEntries
{
    // Create a new data container for the stuff that comes back from the service
    xmlData = [[NSMutableData alloc]init];

    // Construct a URL that will ask the service for what you want -
    NSURL *url = [NSURL URLWithString:@"http://kyfbnewsroom.com/category/public-affairs/feed"];

    // Put that URL into an NSURLRequest
    NSURLRequest *req = [NSURLRequest requestWithURL:url];

    // Create a connection that will exchange this request for data from the URL
    connection = [[NSURLConnection alloc]initWithRequest:req delegate:self startImmediately:YES];
}

- (id)initWithStyle:(UITableViewStyle)style
{
    self = [super initWithStyle:style];

    if (self)
    {
        [self fetchEntries];
    }

    return self;
}

// This method will be called several times as the data arrives
- (void)connection:(NSURLConnection *)conn didReceiveData:(NSData *)data
{
    // Add the incoming chunk of data to the container we are keeping
    // The data always comes in the correct order
    [xmlData appendData:data];
}

- (void)connectionDidFinishLoading:(NSURLConnection *)conn
{
    /* We are just checking to make sure we are getting the XML
     NSString *xmlCheck = [[NSString alloc]initWithData:xmlData encoding:NSUTF8StringEncoding];
     NSLog(@"xmlCheck = %@", xmlCheck);*/

    // Create the parser object with the data received from the web service
    NSXMLParser *parser = [[NSXMLParser alloc]initWithData:xmlData];

    // Give it a delegate
    [parser setDelegate:self];

    //Tell it to start parsing - the document will be parsed and the delegate of NSXMLParser will get all of its delegate messages sent to it before this line finishes execution - it is blocking
    [parser parse];

    // Get rid of the XML data as we no longer need it
    xmlData = nil;

    // Reload the table.. for now, the table will be empty
    [[self tableView]reloadData];

    NSLog(@"%@\n %@\n %@\n", channel, [channel title], [channel infoString]);
}

- (void)connection:(NSURLConnection *)conn didFailWithError:(NSError *)error
{
    // Release the connection object, we're done with it
    connection = nil;

    // Release the xmlData object, we're done with it
    xmlData = nil;

    // Grab the description of the error object passed to us
    NSString *errorString = [NSString stringWithFormat:@"Fetch failed: %@", [error localizedDescription]];

    // Create and show an alert view with this error displayed
    UIAlertView *av = [[UIAlertView alloc]initWithTitle:@"Error" message:errorString delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
    [av show];
}

- (void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    // Push the web view controller onto the navigation stack - this implicitly creates the web view controller's view the first time through
    // [[self navigationController]pushViewController:webViewController animated:YES];
    [self.navigationController pushViewController:webViewController animated:YES];

    // Grab the selected item
    RSSItem *entry = [[channel items]objectAtIndex:[indexPath row]];

    NSLog(@"Channel Items: %@", [[channel items]objectAtIndex:[indexPath row]]);

    // Construct a URL with the link string of the item
    NSURL *url = [NSURL URLWithString:[entry link]];

    NSLog(@"Link: %@", [entry link]);

    // Construct a request object with that URL
    NSURLRequest *req = [NSURLRequest requestWithURL:url];

    NSLog(@"URL: %@", url);

    // Load the request into the web view
    [[webViewController webView]loadRequest:req];

    NSLog(@"Request: %@", req);

    // Set the title of the web view controller's navigation item
    [[webViewController navigationItem]setTitle:[entry title]];

    NSLog(@"Title: %@", [entry title]);
}

-(void)refreshView:(UIRefreshControl *)refresh
{
    refresh.attributedTitle = [[NSAttributedString alloc] initWithString:@"Refreshing data..."];

    // custom refresh logic would be placed here...

    NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
    [formatter setDateFormat:@"MMM d, h:mm a"];
    NSString *lastUpdated = [NSString stringWithFormat:@"Last updated on %@",[formatter stringFromDate:[NSDate date]]];
    refresh.attributedTitle = [[NSAttributedString alloc] initWithString:lastUpdated];
    [refresh endRefreshing];
}


@end

以下是我在另一个视图中的操作方式，但它更容易，因为它只使用一个特定的URL。

//
//  KYFB.m
//  KFBNewsroom
//
//  Created by KFB on 11/14/12.
//  Copyright (c) 2012 com.kfb. All rights reserved.
//

#import "KYFB.h"
#import <MessageUI/MessageUI.h>

@interface KYFB ()

@end

@implementation KYFB
@synthesize webView;

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        self.title = NSLocalizedString(@"KYFB.com", @"KYFB.com");
        self.tabBarItem.image = [UIImage imageNamed:@"kyfb-com"];
    }
    return self;
}

- (void) showMenu
{
    UIActionSheet *actionSheet = [[UIActionSheet alloc] initWithTitle:@"" delegate:self cancelButtonTitle:@"Cancel"
    destructiveButtonTitle:nil otherButtonTitles: @"Open in Safari", nil, nil];

    actionSheet.actionSheetStyle = self.navigationController.navigationBar.barStyle;
    [actionSheet showInView:self.parentViewController.tabBarController.view];
}


- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.
    NSString *urlAddress = @"http:www.kyfb.com";
    NSURL *url = [NSURL URLWithString:urlAddress];
    NSURLRequest *requestObj = [NSURLRequest requestWithURL:url];
    [webView loadRequest:requestObj];

    UIBarButtonItem *systemAction = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAction target:self action:@selector(showMenu)];
    self.navigationItem.rightBarButtonItem = systemAction;
}

- (void)actionSheet:(UIActionSheet *)modalView clickedButtonAtIndex:(NSInteger)buttonIndex
{
    NSURL *url = [NSURL URLWithString:@"http://www.kyfb.com"];

    switch (buttonIndex)
    {
        case 0:
        {
            [[UIApplication sharedApplication] openURL:url];
            break;
        }
    }

}


- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

@end

我只是不确定如何为WebViewController和ListViewController实现这个想法。

更新：我已经在我的WebViewController类中添加了代码。系统操作按钮现在出现在Web视图导航栏上，按下时它会拉动操作表，但在safari按钮中打开不会执行任何操作。

WebViewController.h

//
//  WebViewController.h
//  KFBNewsroom
//
//  Created by KFB on 10/16/12.
//  Copyright (c) 2012 com.kfb. All rights reserved.
//

#import <Foundation/Foundation.h>

// @interface WebViewController : NSObject
@interface WebViewController : UIViewController <UIActionSheetDelegate>
{
    IBOutlet UIWebView *webView;
}

@property (nonatomic, readonly)UIWebView *webView;

@end

WebViewController.m

//
//  WebViewController.m
//  KFBNewsroom
//
//  Created by KFB on 10/16/12.
//  Copyright (c) 2012 com.kfb. All rights reserved.
//

#import "WebViewController.h"

@implementation WebViewController
@synthesize webView;

- (void)loadView
{
    // Create an instance of UIWebView as large as the screen
    CGRect screenFrame = [[UIScreen mainScreen]applicationFrame];
    UIWebView *wv = [[UIWebView alloc]initWithFrame:screenFrame];
    // 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
{
    UIActionSheet *actionSheet = [[UIActionSheet alloc] initWithTitle:@"" delegate:self cancelButtonTitle:@"Cancel"
                                               destructiveButtonTitle:nil otherButtonTitles: @"Open in Safari", nil, nil];

    actionSheet.actionSheetStyle = self.navigationController.navigationBar.barStyle;
    [actionSheet showInView:self.parentViewController.tabBarController.view];
}

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view from its nib.

    UIBarButtonItem *systemAction = [[UIBarButtonItem alloc] initWithBarButtonSystemItem:UIBarButtonSystemItemAction target:self action:@selector(showMenu)];
    self.navigationItem.rightBarButtonItem = systemAction;
}

- (void)actionSheet:(UIActionSheet *)modalView clickedButtonAtIndex:(NSInteger)buttonIndex
{
    // NSURL *url = [NSURL URLWithString:@"http://www.kyfb.com"];
    NSURL *url= webView.request.URL;

    switch (buttonIndex)
    {
        case 0:
        {
            [[UIApplication sharedApplication] openURL:url];
            break;
        }
    }

}

@end

Answer 1

在clickedButtonAtIndex:中，您可以使用网络视图的当前网址：

NSURL *url= webView.request.URL;
//or NSURL *url = [NSURL URLWithString:webView.request.URL.absoluteString];