从未调用可达性通知

Question

我在代码中使用Reachability很困难.我想通过在启动时启动观察者然后只是接收更改通知来保持它非常简单.在以下代码中,永远不会调用reachabilityChanged方法.我尝试了很多迭代,但这是最简单的版本.它编译并运行.请帮忙...

**** AppDelegate.h代码****

#import <UIKit/UIKit.h>

#ifdef PHONEGAP_FRAMEWORK
    #import <PhoneGap/PGViewController.h>
    #import <PhoneGap/PGURLProtocol.h>
    #import <PhoneGap/Reachability.h>
#else
    #import "PGViewController.h"
    #import "PGURLProtocol.h"
    #import "Reachability.h"

#endif

@interface AppDelegate : NSObject < UIApplicationDelegate, UIWebViewDelegate, PGCommandDelegate> {
    NSString* invokeString;
}

@property (nonatomic, copy)  NSString* invokeString;
@property (nonatomic, strong) IBOutlet UIWindow* window;
@property (nonatomic, strong) IBOutlet PGViewController* viewController;

@end

**** AppDelegate.m代码段****

#import "AppDelegate.h"

#import "MainViewController.h"

#ifdef PHONEGAP_FRAMEWORK
    #import <PhoneGap/PGPlugin.h>
    #import <PhoneGap/PGURLProtocol.h>
    #import <PhoneGap/Reachability.h>
#else
    #import "PGPlugin.h"
    #import "PGURLProtocol.h"
    #import "Reachability.h"

#endif

@implementation AppDelegate
@synthesize invokeString, window, viewController;

- (void) reachabilityChanged:(NSNotification *)notice
{

    NSLog(@"???????? CODE NEVER GETS HERE ??????????");

    Reachability *reach = [notice object];
    NSParameterAssert([reach isKindOfClass: [Reachability class]]);
    NetworkStatus remoteHostStatus = [reach currentReachabilityStatus];

    if(remoteHostStatus == NotReachable) {NSLog(@"**** Not Reachable ****");}
    else if (remoteHostStatus == ReachableViaWiFi) {NSLog(@"**** wifi ****"); }
    else if (remoteHostStatus == ReachableViaWWAN) {NSLog(@"**** cell ****"); }
}

- (BOOL) application:(UIApplication*)application didFinishLaunchingWithOptions:(NSDictionary*)launchOptions
{    

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:kReachabilityChangedNotification object:nil];

    Reachability *reach = [Reachability reachabilityForInternetConnection];
    [reach startNotifier];

    NetworkStatus remoteHostStatus = [reach currentReachabilityStatus];

    NSLog(@”???? ALWAYS INITS WITH Not Reachable ????”);
    if(remoteHostStatus == NotReachable) {NSLog(@"init **** Not Reachable ****");}
    else if (remoteHostStatus == ReachableViaWiFi) {NSLog(@"int **** wifi ****"); }
    else if (remoteHostStatus == ReachableViaWWAN) {NSLog(@"init **** cell ****"); }

    // ...

}

@end

Answer 1

你的对象Reachability是自动释放所以它是dealloc并且不再工作了.

我尝试你的代码,它对我有用:

AppDelegate.h代码

[...]
@property (retain, nonatomic)  Reachability* reach;
[...]

AppDelegate.m代码段

[...]
@synthesize reach;

- (void) reachabilityChanged:(NSNotification *)notice
{

    NSLog(@"!!!!!!!!!! CODE IS CALL NOW !!!!!!!!!!");

    NetworkStatus remoteHostStatus = [reach currentReachabilityStatus];

    if(remoteHostStatus == NotReachable) {NSLog(@"**** Not Reachable ****");}
    else if (remoteHostStatus == ReachableViaWiFi) {NSLog(@"**** wifi ****"); }
    else if (remoteHostStatus == ReachableViaWWAN) {NSLog(@"**** cell ****"); }
}

- (BOOL) application:(UIApplication*)application didFinishLaunchingWithOptions:(NSDictionary*)launchOptions
{    

    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:kReachabilityChangedNotification object:nil];

    self.reach = [Reachability reachabilityForInternetConnection]; //retain reach
    [reach startNotifier];

    NetworkStatus remoteHostStatus = [reach currentReachabilityStatus];

    NSLog(@"???? ALWAYS INITS WITH Not Reachable ????");
    if(remoteHostStatus == NotReachable) {NSLog(@"init **** Not Reachable ****");}
    else if (remoteHostStatus == ReachableViaWiFi) {NSLog(@"int **** wifi ****"); }
    else if (remoteHostStatus == ReachableViaWWAN) {NSLog(@"init **** cell ****"); }

    // ...

}

[...]
-(void)dealloc{
    [reach release];
    [super dealloc];
}

@end