Question

I’m looking at the crash log for a device that’s testing an app and I see the following lines…

objc_exception_throw + 33

[__NSArrayM insertObject:atIndex:] +187

The code where this happens is below. appData is an NSDictionary, and I’m expecting imageUrl to be a URL to a png file on the internet.

for (int i = 1; i <= [self getNumberOfScreenshots]; i++) {
    pathToUrl = @"screenshot_";
    pathToUrl = [pathToUrl stringByAppendingString:[[NSNumber numberWithInt:i] stringValue]];
    imageUrl = [self.appData valueForKey:pathToUrl];
    imageData = [[NSData alloc]initWithContentsOfURL:[NSURL URLWithString:imageUrl]];
    [NSMutableArrayObj addObject:imageData];
}

What would cause this type of error? The error happens very rarely..could it be that imageData is sometimes nil because it fails to download the png image off the url, so that throws that exception when I try to add it to the NSMutableArrayObj?

Thanks!

Answer 1

there may two reasons as you have not described error more specically

1) Actually your not allocating the memory to array

2) inserting nil value to array. To stop inserting nil do this:

 if(imageData)
 {
   [NSMutableArrayObj addObject:imageData];
 }