iOS应用程序崩溃-我怀疑这与使用WebSocket的UIWebView有关

我目前没有使用applicationWillResignActive/applicationWillEnterForeground或任何类似的工具，因为我不确定如何处理我遇到的这个问题

如果我打开应用程序，按主屏幕，等待大约5分钟，然后再次尝试返回应用程序，我的应用程序会不断崩溃

该应用程序主要是一个加载node.js驱动的websocket的UIWebView，因此我认为这是罪魁祸首

当用户离开应用程序时，我如何阻止UIWebView做任何事情（我猜需要使用applicationWillResignActive）。我已经玩了半打创意，我一辈子都无法让应用程序停止崩溃

我目前的想法是：

- (void)applicationWillResignActive:(UIApplication *)application
{
[[NSNotificationCenter defaulCenter] postNotificationName:@"EnterBackground" object:Nil userInfo: Nil];
}

---

…然后从那里编辑ViewController.m文件，对该页面上的UIWebView执行某些操作。问题是，什么会阻止UIWebView在后台执行任何操作？我已经尝试停止加载，但由于某些原因没有成功，否则它仍然会崩溃。

我无法重现确切的问题（

WebThread:EXC\u BAD\u ACCESS（code=1，address=0x5）

-取自您的），但我确实注意到WebSocket消息正在被缓冲，因此如果您将应用程序留在后台足够长的时间，您将遇到内存压力问题，这可能是导致此崩溃的原因

然而，在研究这个问题的过程中，我确实设法使应用程序可靠地崩溃，因为

EXC_BAD_访问

源于

WebThread

，因此我将在这里发布详细信息，希望它对您或其他人有用

出于这个问题的目的，我的WebSocket服务器只是将时间每秒广播给任何连接的客户端

正如我所提到的，我注意到当应用程序处于后台时，UIWebView正在缓冲WebSocket消息。为了防止出现这种情况，我想在将应用程序移到后台时关闭WebSocket连接

在托管UIWebView的视图控制器中，我为

UIApplicationWillResignActiveNotification

注册了一个选择器，在该选择器中，我在网页中调用了一个JavaScript函数，该函数在WebSocket对象上调用了

close

ViewController.m:

- (void)viewDidLoad
{
    [super viewDidLoad];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(appWillResignActive:)
                                                 name:UIApplicationWillResignActiveNotification
                                               object:nil];
}

- (void)appWillResignActive:(NSNotification *)notification
{
    [self.webView stringByEvaluatingJavaScriptFromString:@"closeWebSocket();"];
}

function closeWebSocket() {
    socket.close(); // socket is an instance of WebSocket
    socket = undefined;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(appWillResignActive:)
                                                 name:UIApplicationWillResignActiveNotification
                                               object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(appDidBecomeActive:)
                                                 name:UIApplicationDidBecomeActiveNotification
                                               object:nil];
}

- (void)appWillResignActive:(NSNotification *)notification
{
    [self.webView stringByEvaluatingJavaScriptFromString:@"closeWebSocket();"];
}

- (void)appDidBecomeActive:(NSNotification *)notification
{
    [self.webView stringByEvaluatingJavaScriptFromString:@"openWebSocket();"];
}

function openWebSocket() {  
    socket = new WebSocket("ws://" + document.location.host + "/ping");  

    socket.onopen = function () { console.log("Opened"); };
    socket.onmessage = function (message) { 
      var log = $('#log');
      log.html(message.data + '<br>' + log.html()); 
      console.log(message.data);
    };
    socket.onclose = function () { console.log("Closed"); };
}

网页：

- (void)viewDidLoad
{
    [super viewDidLoad];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(appWillResignActive:)
                                                 name:UIApplicationWillResignActiveNotification
                                               object:nil];
}

- (void)appWillResignActive:(NSNotification *)notification
{
    [self.webView stringByEvaluatingJavaScriptFromString:@"closeWebSocket();"];
}

function closeWebSocket() {
    socket.close(); // socket is an instance of WebSocket
    socket = undefined;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(appWillResignActive:)
                                                 name:UIApplicationWillResignActiveNotification
                                               object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(appDidBecomeActive:)
                                                 name:UIApplicationDidBecomeActiveNotification
                                               object:nil];
}

- (void)appWillResignActive:(NSNotification *)notification
{
    [self.webView stringByEvaluatingJavaScriptFromString:@"closeWebSocket();"];
}

- (void)appDidBecomeActive:(NSNotification *)notification
{
    [self.webView stringByEvaluatingJavaScriptFromString:@"openWebSocket();"];
}

function openWebSocket() {  
    socket = new WebSocket("ws://" + document.location.host + "/ping");  

    socket.onopen = function () { console.log("Opened"); };
    socket.onmessage = function (message) { 
      var log = $('#log');
      log.html(message.data + '<br>' + log.html()); 
      console.log(message.data);
    };
    socket.onclose = function () { console.log("Closed"); };
}

当应用程序移回前台时，我希望WebSocket重新连接，因此我注册了另一个选择器，这次是为

UIApplicationIDBecMeactiveNotification

注册的，在该选择器中调用了另一个初始化WebSocket连接的函数

ViewController.m:

- (void)viewDidLoad
{
    [super viewDidLoad];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(appWillResignActive:)
                                                 name:UIApplicationWillResignActiveNotification
                                               object:nil];
}

- (void)appWillResignActive:(NSNotification *)notification
{
    [self.webView stringByEvaluatingJavaScriptFromString:@"closeWebSocket();"];
}

function closeWebSocket() {
    socket.close(); // socket is an instance of WebSocket
    socket = undefined;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(appWillResignActive:)
                                                 name:UIApplicationWillResignActiveNotification
                                               object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(appDidBecomeActive:)
                                                 name:UIApplicationDidBecomeActiveNotification
                                               object:nil];
}

- (void)appWillResignActive:(NSNotification *)notification
{
    [self.webView stringByEvaluatingJavaScriptFromString:@"closeWebSocket();"];
}

- (void)appDidBecomeActive:(NSNotification *)notification
{
    [self.webView stringByEvaluatingJavaScriptFromString:@"openWebSocket();"];
}

function openWebSocket() {  
    socket = new WebSocket("ws://" + document.location.host + "/ping");  

    socket.onopen = function () { console.log("Opened"); };
    socket.onmessage = function (message) { 
      var log = $('#log');
      log.html(message.data + '<br>' + log.html()); 
      console.log(message.data);
    };
    socket.onclose = function () { console.log("Closed"); };
}

网页：

- (void)viewDidLoad
{
    [super viewDidLoad];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(appWillResignActive:)
                                                 name:UIApplicationWillResignActiveNotification
                                               object:nil];
}

- (void)appWillResignActive:(NSNotification *)notification
{
    [self.webView stringByEvaluatingJavaScriptFromString:@"closeWebSocket();"];
}

function closeWebSocket() {
    socket.close(); // socket is an instance of WebSocket
    socket = undefined;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(appWillResignActive:)
                                                 name:UIApplicationWillResignActiveNotification
                                               object:nil];

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(appDidBecomeActive:)
                                                 name:UIApplicationDidBecomeActiveNotification
                                               object:nil];
}

- (void)appWillResignActive:(NSNotification *)notification
{
    [self.webView stringByEvaluatingJavaScriptFromString:@"closeWebSocket();"];
}

- (void)appDidBecomeActive:(NSNotification *)notification
{
    [self.webView stringByEvaluatingJavaScriptFromString:@"openWebSocket();"];
}

function openWebSocket() {  
    socket = new WebSocket("ws://" + document.location.host + "/ping");  

    socket.onopen = function () { console.log("Opened"); };
    socket.onmessage = function (message) { 
      var log = $('#log');
      log.html(message.data + '<br>' + log.html()); 
      console.log(message.data);
    };
    socket.onclose = function () { console.log("Closed"); };
}

---

再次运行应用程序时，WebSocket连接已建立，收到消息，应用程序已后台运行。几秒钟后，当我将应用程序带回前台时，应用程序没有崩溃，消息再次通过WebSocket连接发送。

您正在自定义NSURL协议吗？在webView控制器中执行诸如registerClass之类的操作？发布你的崩溃日志或web视图代码。你能找到你的应用程序崩溃的原因吗？显示崩溃的堆栈跟踪。回答不错@neilco。一个建议是，您是否可以不在Javascript中使用暂停/恢复事件？它们应该很好地转换为appWillResignActive/appDidBecomeActive。