什么原因导致错误NSNetServicesErrorCode =“ -72000”？

Question

i创建一个简单的浏览器，可以使用UIWebview加载本地文件。首先，当我尝试预览html文件时，uiwebview可以加载源文件并对其进行预览。但是，当我最小化应用程序（应用程序进入后台），然后再次打开应用程序后，出现了此错误：

Error Dict: {
    NSNetServicesErrorCode = "-72000";
    NSNetServicesErrorDomain = 10;
}

之后，uiwebview无法加载源文件，当我在(void)webView:(UIWebView *)webView didFailLoadWithError:(NSError *)error中记录错误时，它显示此消息：

Error Domain=NSURLErrorDomain Code=-1004 "Could not connect to the server." UserInfo=0x53d610 {NSErrorFailingURLStringKey=http://localhost:9898/local/a.html?83C66B33-874C-41A7-BBF5-78D1615512DF, NSErrorFailingURLKey=http://localhost:9898/local/a.html?83C66B33-874C-41A7-BBF5-78D1615512DF, NSLocalizedDescription=Could not connect to the server., NSUnderlyingError=0x5ccaa0 "Could not connect to the server."}

应用程序没有崩溃，但旋转指示器从未停止。

有人可以告诉我这是什么原因吗？以及如何解决？

谢谢：）

Answer 1

如果您查看NSNetServices标头内部，将看到以下枚举说明了每个错误：

typedef NS_ENUM(NSInteger, NSNetServicesError) {

/* An unknown error occured during resolution or publication.
*/
    NSNetServicesUnknownError = -72000L,

/* An NSNetService with the same domain, type and name was already present when the publication request was made.
*/
    NSNetServicesCollisionError = -72001L,

/* The NSNetService was not found when a resolution request was made.
*/
    NSNetServicesNotFoundError  = -72002L,

/* A publication or resolution request was sent to an NSNetService instance which was already published or a search request was made of an NSNetServiceBrowser instance which was already searching.
*/
    NSNetServicesActivityInProgress = -72003L,

/* An required argument was not provided when initializing the NSNetService instance.
*/
    NSNetServicesBadArgumentError = -72004L,

/* The operation being performed by the NSNetService or NSNetServiceBrowser instance was cancelled.
*/
    NSNetServicesCancelledError = -72005L,

/* An invalid argument was provided when initializing the NSNetService instance or starting a search with an NSNetServiceBrowser instance.
*/
    NSNetServicesInvalidError = -72006L,

/* Resolution of an NSNetService instance failed because the timeout was reached.
*/
    NSNetServicesTimeoutError = -72007L,

};

您遇到服务冲突错误，这意味着具有相同域，类型和名称的网络服务已经在网络上发布了它们的服务。

通常，我总是在头文件中查询错误代码。它们几乎总是由一个枚举值分配，并且该枚举通常具有比使用的数字更具描述性的名称。

Answer 2

问题似乎是您尝试连接的主机：http://localhost:9898/local/[..]

您计算机上的本地主机是您的计算机，ipad上的本地主机是您的ipad-测试使用可解析的域名或IP地址。

Answer 3

Sergiu Todirascu在问题中的评论为我解决了。 Mac Sandbox造成了这种情况，我不得不在“权限”选项卡中打开“网络”，就我的情况而言为“入站和出站网络”复选框。创建一个答案，这样更容易看到。