I have an app that reads an RSS feed and when a row in the table view is selected, it opens the article in a web view. 我想要一个按钮来显示一个带有在 Safari 中打开 URL 的选项的操作表。我正在使用操作表，因为我将在不久的将来向它添加更多按钮。
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
列表视图控制器.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
这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：我已将代码添加到我的 WebViewController 类。系统操作按钮现在出现在 Web 视图导航栏上，按下它会拉起操作表，但在 safari 中打开按钮不会执行任何操作。
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