关闭后从 UIWebView 释放内存/cookie/缓存答案

【问题标题】：Release memory/cookie/cache from UIWebView once closed关闭后从 UIWebView 释放内存/cookie/缓存
【发布时间】：2012-03-15 18:46:37
【问题描述】：

我有一个UIViewController，其中包含一个UIWebView。

我使用 UIViewController 中的 UIWebview 登录到一个网站说 facebook，然后我单击完成，这会关闭视图控制器，我想这将释放视图控制器。但是当我再次打开 UIWebview 时（没有退出应用程序，甚至在终止应用程序后），网页在加载网络视图后仍然登录到 Facebook。我应该如何释放 Web 视图，以便每次单击完成并返回 Web 视图时，Web 视图将始终像“全新”而不登录到我以前登录的任何网站。

- (void)viewDidLoad{
       NSLog(@"webView viewDidLoad called");
       appDelegate = (LoginDBAppDelegate *)[[UIApplication sharedApplication] delegate];
       loginObj = [appDelegate.loginArray objectAtIndex:currentSelectedRow];

       myWebView.delegate = self;
        [super viewDidLoad];
        [self showWebView]; 

}

-(void)showWebView{
    NSLog(@"webView showWebView called");

    NSURL *url = [NSURL URLWithString:loginObj.loginURL];
    NSURLRequest *request = [NSURLRequest requestWithURL:url];


    [myWebView loadRequest:request];
}


-(IBAction)done_Clicked:(id)sender{
    NSLog(@"webView Done_Clicked");

    //dismiss the controller
    [self.navigationController dismissModalViewControllerAnimated:YES];

}

-(void)dealloc{
        [myWebView release];
        myWebView.delegate = nil;
        [activity release];
        [urlTextField release];
        [super dealloc];
}

我试过了，但是没用：

-(IBAction)done_Clicked:(id)sender{
NSLog(@"webView Done_Clicked");

[[NSURLCache sharedURLCache] removeAllCachedResponses]; 
[myWebView stringByEvaluatingJavaScriptFromString:@"var body=document.getElementsByTagName('body')[0];body.style.backgroundColor=(body.style.backgroundColor=='')?'white':'';"];
[myWebView stringByEvaluatingJavaScriptFromString:@"document.open();document.close()"];

//dismiss the controller
[self.navigationController dismissModalViewControllerAnimated:YES];

}

我也试过了，没有成功：

- (void) viewDidDisappear:(BOOL)animated {

NSLog(@"webView viewDidDisappear called");
[super viewDidDisappear:animated];

[self.myWebView removeFromSuperview];
self.myWebView.delegate = nil;
self.myWebView = nil;
[myWebView release];
}

【问题讨论】：

标签： ios caching memory-management uiwebview

【解决方案1】：

从论坛上的某个人那里得到答案，所以感谢他...

将此代码放入 viewDidLoad

//Set Cache
NSURLCache *sharedCache = [[NSURLCache alloc] initWithMemoryCapacity:0 diskCapacity:0 diskPath:nil];
[NSURLCache setSharedURLCache:sharedCache];

//Clear All Cookies
for(NSHTTPCookie *cookie in [[NSHTTPCookieStorage sharedHTTPCookieStorage] cookies]) {

    //if([[cookie domain] isEqualToString:someNSStringUrlDomain]) {

    [[NSHTTPCookieStorage sharedHTTPCookieStorage] deleteCookie:cookie];

}

【讨论】：