How am I leaking NSString in this case?

I have a tableview that has a string on the last row.

@interface MyTableViewController : UIViewController <UITableViewDelegate, UITableViewDataSource>
{
    NSString *loadingMessage;   
}
@property (retain) NSString *loadingMessage;
@synthesize loadingMessage;

- (UITableViewCell *)tableView:(UITableView *)pTableView cellForRowAtIndexPath:(NSIndexP开发者_如何学运维ath *)indexPath {
//some stuff...
        cell.textLabel.text = loadingMessage;
}

Then when some event happens, I will be changing the loading message:

-(void)requestFailed:(NSError*)error {
    self.loadingMessage = [NSString stringWithFormat:@"Failed with error: %@", error];
}

According to instruments I am leaking the loadingMessage string in here... But I don't see why. I thought the count for stringWithFormat is +0, and the setter is +1. I release the string when I dealloc as well. What am i doing wrong?

The code you posted is correct. Indeed, stringWithFormat returns an autoreleased object, so you can assign it directly to a retained property.

So, either you are doing some other assignment in your code, or, more probably, you are not releasing loadingMessage in your dealloc.

Just an hypothesis.

Sergio is right , theres nothing wrong with the code but I have found that string properties need to be copy rather than retain.

Try

@property (copy,readwrite) NSString *loadingMessage;

Might stop the leak