Question

我不知道为什么我的应用程序在此行崩溃

NSData * data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];

这是我的代码：

NSString * urlString = [[NSUserDefaults standardUserDefaults] objectForKey:MAINURL];

NSHTTPURLResponse * response;
NSError * error;
NSMutableURLRequest *request;

request = [[NSMutableURLRequest alloc] initWithURL:[NSURL URLWithString:urlString]
                                    cachePolicy:NSURLRequestReloadIgnoringCacheData
                                   timeoutInterval:120];

if([[[NSUserDefaults standardUserDefaults] objectForKey:@"callWebServiceFor"] isEqualToString:nil]) {
    // [request setValue:[NSString stringWithFormat:@"%d", [postData length]] forHTTPHeaderField:@"Content-Length"];

    NSString * strSessionId = [[NSUserDefaults standardUserDefaults] objectForKey:@"sessionId"];
    if(strSessionId != nil)
        [request setValue:strSessionId forHTTPHeaderField:@"Cookie"];
}
NSData * data = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&error];
// Storing session headers when user logs in successfully
if([[[NSUserDefaults standardUserDefaults] objectForKey:@"callWebServiceFor"] isEqualToString:@"login"]) {
    NSArray * all = [NSHTTPCookie cookiesWithResponseHeaderFields:[response allHeaderFields] forURL:[NSURL URLWithString:urlString]]; //testing
    [[NSHTTPCookieStorage sharedHTTPCookieStorage] setCookies:all forURL:[NSURL URLWithString:urlString] mainDocumentURL:nil];
    NSString * strSessionId;
    for (NSHTTPCookie *cookie in all) {
        strSessionId = [[NSString alloc] initWithString:cookie.value];
        //  NSLog(@"Session value: %@",cookie.key];
        //  NSLog(@"Session value: %@",strSessionId);
    }
    [[NSUserDefaults standardUserDefaults] setObject:strSessionId forKey:@"sessionId"];
    [[NSUserDefaults standardUserDefaults] setObject:nil forKey:@"callWebServiceFor"];
}
if (data != nil) {
    dispatch_async(kBackGroudQueue, ^{
        [self performSelectorOnMainThread:@selector(handleWebServiceResponse:)
                               withObject:data waitUntilDone:YES];
    });
} else {
    [SwapweekUtilViewController showAlert:@"Internet" :@"Check your Internet Connection"];
}

Answer 1

我无法理解为什么您的代码在NSURLConnection sendSynchronousRequest:崩溃，而且您还没有发布堆栈跟踪来验证这一事实，但是此代码可能会崩溃（如果strSessionId为{{1} }}）：

nil

此代码将崩溃：

 [[NSUserDefaults standardUserDefaults] setObject:strSessionId forKey:@"sessionId"];

（使用[[NSUserDefaults standardUserDefaults] setObject:nil forKey:@"callWebServiceFor"];从用户默认值中删除对象。）

这也很差：

removeObjectForKey:

（代之以if([[[NSUserDefaults standardUserDefaults] objectForKey:@"callWebServiceFor"] isEqualToString:nil]) {测试。）

这也很糟糕：

[NSString length] == 0

（for (NSHTTPCookie *cookie in all) { strSessionId = [[NSString alloc] initWithString:cookie.value]; // NSLog(@"Session value: %@",cookie.key]; // NSLog(@"Session value: %@",strSessionId); }一旦你有一个非空的break而只是做strSessionId而不是那个strSessionId = cookie.key;。）

应用程序在ios中崩溃了sendSynchronousRequest

1 个答案: