Get EXC_BAD_ACCESS when tableview get data from URL? - objective-c

Question

My tableview is get XML data from URL,First I declare a NSMutableArray *dataArray;
and this is how I get the data in my TableviewSample.m
- (void)getDataFromURL{
NSString *theURLAsString = [NSString stringWithFormat:GetAllData];//<-EXE_BAD_ACCESS HERE
//#define stringWithFormat:GetAllData #"http://192.168.10.28/req_alldata.php"
NSURL *theURL = [NSURL URLWithString:theURLAsString];
self.dataArray = [NSMutableArray arrayWithContentsOfURL:theURL];
}
Then I just get the elements form this array to my tableview ...
But here I have to say one more thing , actually it won't crash before I add another view...
I add a bar button to go to a webView , this webView is use to load a IP Cam stream video
When I back to the tableview , It will appear EXC_BAD_ACCESS
This is odd things I cannot to solve it...because both side code are all looks normal
If I remove this webview ,no matter how I run the program ,it won't crash...
And sometimes I leave the webView I will receive memory warning :level 2
But just only one time.
or do I use a wrong way to open an ip cam stream ???
Thanks for all reply : )
OK,here is the code different I use in my webview class
This is first version I use
- (void)viewDidAppear:(BOOL)animated{
NSString *directGoToWebCam = [NSString stringWithFormat:GetAllData];
self.IPCamWebView=[[[UIWebView alloc] initWithFrame:CGRectMake(0,0,640,960)] autorelease];
[self.IPCamWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:directGoToWebCam]]];
[self.view addSubview:self.IPCamWebView];
}

Answer 1

Where does GetAllData come from? It looks like that isn't pointing to anything. More code, the exact error, and a more careful description will go a long way here.

Answer 2

It probably has something to do with the use of #define which does not say anything about the type of the object you are using.
If you want to define a constant string in your code the best would be to use something like this:
static NSString *GetAllData = #"192.168.10.28/req_alldata.php";
Where you need to use the string you can simply write:
NSString *GoToWebCam = [NSString stringWithString:GetAllData];