引发iOS异常：无法识别的选择器已发送到实例

Question

I have a problem. I am calling a method in another class. I call it before and it works perfect but I call back in another method near the end of the class and I have this error:

-(void)methodOne:(NSString*)myString
{
    mySecondClasss *second = [[mySecondClasss init] autorelease];
    [second doSomething:myString];
    /*
     more code
     */
}

-(void)methodTwo:(NSString*)myString
{
    mySecondClasss *second = [[mySecondClasss init] autorelease];
    [second doSomething:myString];
    /*
     more code
     */
}

In the second I'm getting this error:

Exception was thrown: -[mySecondClasss doSomething:]: unrecognized selector sent to instance. I don't understand why works once but not the second time. Any of you can give me some pointers of how can I fix this?

I'll really appreciate your help.

Answer 1

Since IOS 5 you have ARC (Automatic Reference Counting) which is automatically releasing the object correctly. Anyway you are not allocating the memory for the mySecondClasss class. Not sure why it even worked in the first method.

Instead of using

mySecondClasss *second = [[mySecondClasss init] autorelease];

Try using

mySecondClasss *second = [[mySecondClasss alloc] init];

Answer 2

Are you sure that you are sending a string to the function? The error implies that the function is not getting a string.

For example:

[self methodOne:@"Properly formatted string"];