Question: I have a method like this:

```
-(void)A:(int)a B:(int)b{    
}

```

and want to put the method into a new thread:

```
NSInvocationOperation *theOp = [[NSInvocationOperation alloc]initWithTarget:self selector:@selector(A:B:) object:nil];

```

but "EXC\_BAD\_ACCESS".

Answer: 
If possible, try to have one array or dictionary as the parameter to the selector.
Then when you are invoking convert your two params into one object (either array or dictionary) and send that object.
In the selector, i think you can get them back from array or dictionary.
You don't need the second B:

usuage would be:

```
[[NSInvocationOperation alloc]initWithTarget:self selector:@selector(A:) object:nil];

```