ipad - 什么导致错误 NSNetServicesErrorCode = "-72000"？

Question

我创建了一个简单的浏览器，可以使用 UIWebview 加载本地文件。首先，当我尝试预览 html 文件时，uiwebview 可以加载源文件并进行预览。但是在我最小化应用程序(应用程序进入后台)，然后再次打开应用程序后，我收到了这个错误:

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，但旋转指示器永远不会停止。

有人能告诉我是什么原因造成这种情况吗？以及如何解决它？

谢谢 :)

Answer 1

如果您查看 NSNetServices 的内部 header ，您将看到解释每个错误的以下枚举:

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,

};

您收到服务冲突错误，这意味着具有相同域、类型和名称的网络服务已经在您的网络上发布其服务。

一般来说，我总是查阅头文件中的错误代码。它们几乎总是由枚举值分配，并且枚举通常具有比使用的数字更具描述性的名称。