我想检查一下我是否可以在iOS上使用Cocoa Touch库或在macOS上使用Cocoa库连接互联网。
我想出了一个方法来做这个使用NSURL。我的方法似乎有点不可靠(因为即使谷歌也可能有一天宕机，依赖第三方似乎很糟糕)，虽然如果谷歌没有响应，我可以检查其他一些网站的响应，但这似乎是浪费和不必要的应用程序开销。
- (BOOL)connectedToInternet {
NSString *URLString = [NSString stringWithContentsOfURL:[NSURL URLWithString:@"http://www.google.com"]];
return ( URLString != NULL ) ? YES : NO;
}
是我做得不好，(更不用说stringWithContentsOfURL已弃用在iOS 3.0和macOS 10.4)，如果是这样，有什么更好的方法来实现这一点?
当前回答
我喜欢把事情简单化。我的做法是:
//Class.h
#import "Reachability.h"
#import <SystemConfiguration/SystemConfiguration.h>
- (BOOL)connected;
//Class.m
- (BOOL)connected
{
Reachability *reachability = [Reachability reachabilityForInternetConnection];
NetworkStatus networkStatus = [reachability currentReachabilityStatus];
return networkStatus != NotReachable;
}
然后，每当我想要查看是否有连接时，我就使用这个:
if (![self connected]) {
// Not connected
} else {
// Connected. Do some Internet stuff
}
这个方法不会等待网络状态的改变来执行操作。它只在您要求时测试状态。
其他回答
Swift 5及以后:
public class Reachability {
class func isConnectedToNetwork() -> Bool {
var zeroAddress = sockaddr_in()
zeroAddress.sin_len = UInt8(MemoryLayout<sockaddr_in>.size)
zeroAddress.sin_family = sa_family_t(AF_INET)
guard let defaultRouteReachability = withUnsafePointer(to: &zeroAddress, {
$0.withMemoryRebound(to: sockaddr.self, capacity: 1) {
SCNetworkReachabilityCreateWithAddress(nil, $0)
}
}) else {
return false
}
var flags: SCNetworkReachabilityFlags = []
if !SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags) {
return false
}
let isReachable = flags.contains(.reachable)
let needsConnection = flags.contains(.connectionRequired)
return (isReachable && !needsConnection)
}
像这样调用这个类:
if Reachability.isConnectedToNetwork() == true {
// Do something
} else {
// Do something
}
使用Apple的Reachability代码，我创建了一个函数，可以正确地检查这一点，而无需包含任何类。
在你的项目中包含SystemConfiguration.framework。
进行一些导入:
#import <sys/socket.h>
#import <netinet/in.h>
#import <SystemConfiguration/SystemConfiguration.h>
现在只需调用这个函数:
/*
Connectivity testing code pulled from Apple's Reachability Example: https://developer.apple.com/library/content/samplecode/Reachability
*/
+(BOOL)hasConnectivity {
struct sockaddr_in zeroAddress;
bzero(&zeroAddress, sizeof(zeroAddress));
zeroAddress.sin_len = sizeof(zeroAddress);
zeroAddress.sin_family = AF_INET;
SCNetworkReachabilityRef reachability = SCNetworkReachabilityCreateWithAddress(kCFAllocatorDefault, (const struct sockaddr*)&zeroAddress);
if (reachability != NULL) {
//NetworkStatus retVal = NotReachable;
SCNetworkReachabilityFlags flags;
if (SCNetworkReachabilityGetFlags(reachability, &flags)) {
if ((flags & kSCNetworkReachabilityFlagsReachable) == 0)
{
// If target host is not reachable
return NO;
}
if ((flags & kSCNetworkReachabilityFlagsConnectionRequired) == 0)
{
// If target host is reachable and no connection is required
// then we'll assume (for now) that your on Wi-Fi
return YES;
}
if ((((flags & kSCNetworkReachabilityFlagsConnectionOnDemand ) != 0) ||
(flags & kSCNetworkReachabilityFlagsConnectionOnTraffic) != 0))
{
// ... and the connection is on-demand (or on-traffic) if the
// calling application is using the CFSocketStream or higher APIs.
if ((flags & kSCNetworkReachabilityFlagsInterventionRequired) == 0)
{
// ... and no [user] intervention is needed
return YES;
}
}
if ((flags & kSCNetworkReachabilityFlagsIsWWAN) == kSCNetworkReachabilityFlagsIsWWAN)
{
// ... but WWAN connections are OK if the calling application
// is using the CFNetwork (CFSocketStream?) APIs.
return YES;
}
}
}
return NO;
}
这是为你测试的iOS 5。
重要:该检查应该始终异步执行。下面的大多数答案是同步的，所以要小心，否则你会冻结你的应用程序。
斯威夫特
通过CocoaPods或Carthage安装:https://github.com/ashleymills/Reachability.swift 通过闭包测试可达性 let reachability =可达性()! 可达性。whenReachable ={可达性 如果可达性。连接== .wifi { 打印(“可通过WiFi访问”) }其他{ 打印(“可通过蜂窝连接”) } } 可达性。whenUnreachable = {_ in 打印(“不可以”) } {做 尝试reachability.startNotifier () } catch { 打印("无法启动通知程序") }
objective - c
将SystemConfiguration框架添加到项目中，但不要担心将它包含在任何地方 添加Tony Million版本的Reachability.h和Reachability。m到项目(在这里找到:https://github.com/tonymillion/Reachability) 更新接口部分 #进口“Reachability.h” //在视图控制器的.m文件中添加这个接口 @interface MyViewController () ｛ 可达性* internetReachableFoo; ｝ @end 然后在视图控制器的。m文件中实现这个方法，你可以调用它 //检查我们是否有网络连接 - (void) testInternetConnection ｛ internetReachableFoo = [Reachability reachabilityWithHostname:@"www.google.com"]; //网络可达 internetReachableFoo。reachableBlock = ^(可达性*reach) ｛ //更新主线程的UI 设置(dispatch_get_main_queue()、^ { NSLog(@“Yayyy，我们有了互联网!”); })； }; //网络不可达 internetReachableFoo。unreachableBlock = ^(可达性*reach) ｛ //更新主线程的UI 设置(dispatch_get_main_queue()、^ { NSLog(@"有人破坏了互联网:("); })； }; [internetReachableFoo startNotifier]; ｝
重要提示:Reachability类是项目中最常用的类之一，因此您可能会遇到与其他项目的命名冲突。如果发生这种情况，您将不得不重命名Reachability.h和Reachability对中的一个。M文件到其他文件来解决这个问题。
注意:您使用的域名并不重要。这只是在测试通往任何领域的入口。
使用http://huytd.github.io/datatify/。这比自己添加库和编写代码要容易得多。
首先下载reachability类并放入reachability.h和reachability.h。m文件在你的Xcode。
最好的方法是创建一个通用的Functions类(NSObject)，这样你就可以在任何类中使用它。这是检查网络连接可达性的两种方法:
+(BOOL) reachabiltyCheck
{
NSLog(@"reachabiltyCheck");
BOOL status =YES;
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(reachabilityChanged:)
name:kReachabilityChangedNotification
object:nil];
Reachability * reach = [Reachability reachabilityForInternetConnection];
NSLog(@"status : %d",[reach currentReachabilityStatus]);
if([reach currentReachabilityStatus]==0)
{
status = NO;
NSLog(@"network not connected");
}
reach.reachableBlock = ^(Reachability * reachability)
{
dispatch_async(dispatch_get_main_queue(), ^{
});
};
reach.unreachableBlock = ^(Reachability * reachability)
{
dispatch_async(dispatch_get_main_queue(), ^{
});
};
[reach startNotifier];
return status;
}
+(BOOL)reachabilityChanged:(NSNotification*)note
{
BOOL status =YES;
NSLog(@"reachabilityChanged");
Reachability * reach = [note object];
NetworkStatus netStatus = [reach currentReachabilityStatus];
switch (netStatus)
{
case NotReachable:
{
status = NO;
NSLog(@"Not Reachable");
}
break;
default:
{
if (!isSyncingReportPulseFlag)
{
status = YES;
isSyncingReportPulseFlag = TRUE;
[DatabaseHandler checkForFailedReportStatusAndReSync];
}
}
break;
}
return status;
}
+ (BOOL) connectedToNetwork
{
// Create zero addy
struct sockaddr_in zeroAddress;
bzero(&zeroAddress, sizeof(zeroAddress));
zeroAddress.sin_len = sizeof(zeroAddress);
zeroAddress.sin_family = AF_INET;
// Recover reachability flags
SCNetworkReachabilityRef defaultRouteReachability = SCNetworkReachabilityCreateWithAddress(NULL, (struct sockaddr *)&zeroAddress);
SCNetworkReachabilityFlags flags;
BOOL didRetrieveFlags = SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags);
CFRelease(defaultRouteReachability);
if (!didRetrieveFlags)
{
NSLog(@"Error. Could not recover network reachability flags");
return NO;
}
BOOL isReachable = flags & kSCNetworkFlagsReachable;
BOOL needsConnection = flags & kSCNetworkFlagsConnectionRequired;
BOOL nonWiFi = flags & kSCNetworkReachabilityFlagsTransientConnection;
NSURL *testURL = [NSURL URLWithString:@"http://www.apple.com/"];
NSURLRequest *testRequest = [NSURLRequest requestWithURL:testURL cachePolicy:NSURLRequestReloadIgnoringLocalCacheData timeoutInterval:20.0];
NSURLConnection *testConnection = [[NSURLConnection alloc] initWithRequest:testRequest delegate:self];
return ((isReachable && !needsConnection) || nonWiFi) ? (testConnection ? YES : NO) : NO;
}
现在您可以通过调用这个类方法来检查任何类中的网络连接。
