Release memory/cookie/cache from UIWebView once closed

问题

I have a UIViewController which contains a UIWebView.

i login to a website for say facebook using the UIWebview in the UIViewController then i click on done, which dismiss the view controller, which i suppose will release the view controller. but when i open the UIWebview again (without exiting the app and also even after terminating the app) the webpage is still log into Facebook after the web view loads. How should i release the web view so that every time i click on done and return back to the web view, the web view will always be like "brand new" not log-on to any website that i had previously log-on to.

- (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];
}

I have tried this but it didn't work:

-(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];

}

I have also tried this without any success:

- (void) viewDidDisappear:(BOOL)animated {

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

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

回答1:

Got the answer from someone on the forum, so credit to him...

Place this code in 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];

}

来源：https://stackoverflow.com/questions/9445645/release-memory-cookie-cache-from-uiwebview-once-closed

标签

ios

caching

memory-management

uiwebview