NSMutableDictionary EXC_BAD_ACCESS

I know there are many questions about this topic but non of them work for me because mine is a little weird.

First of all I create a static singleton class. and declare a variable of NSMutableDictionary

static NSMutableDictionary* mydic
@implementation mySingleton

-(mySingleton*)getInstance
{
    static mySingleton *sharedInstance;
    @synchronized(self)
    {
       if(!sharedInstance)
       {
          sharedInstance = [[mySingleton alloc] init];
          mydic = [[NSMutableDictionary alloc] initWithCapacity:1];
       }
       return sharedInstance;
    }
}

-(NSMutableDictionary*)getDictionary
{
   return myDic;
}

then I call this NSMutableDictionary from another class like the below.

NSMutableDictionary* singletonDictionary = [[mySingleton getInstance] getDictionary];

MyOtherClass* myclass = [singletonDictionary objectForKey:key];// Key is NSString
// Here I can see whole the va开发者_JAVA百科lues I added to myClass for that key
NSArray *checkKey = [singletonDictionary allKeys];
for(int i = 0; i < [singletonDictionary count]; i++)
{
    NSLog(@"%@",[checkKey objectAtIndex:i]);// here I can see my key is there
}

[singletonDictionary removeObjectForKey:key];// here it crashes EXC_BAD_ACCESS

I am gonna get crazy about this problem. If someone has an idea please share it with me.

EDIT :

MyOtherClass * myinstance = [[MyOtherClass alloc] init];
// Fill up the instance with the desired variable here
// Forexample
// myinstance.name = [NSString stringWithFormat:@"myInstanceName"];
.
.
.

[[[mySingleton getInstance] getDictionary] setObject:myinstance forKey:key]// key is an NSString*
[myinstance release];

Thanks for help.

Omer Faruk KURT

So many problems, where to start...?

At least, it seems your getInstance method is not returning anything; it should probably return mySingleton. This could explain your EXEC_BAD_ACCESS, as singletonDictionary is probably nil as things stand.

Your singleton instantiation is wrong too - you need to check if the singleton has already been created, and return it if it has. Otherwise you can reallocate singletons, which is absurd.

Static references are poor design here, better to subclass and declare members in the header file.

This might fix your problems, but you're clearly jumping in at the deep end and you're going to encounter more trouble. I think you need to find good examples of code in texts or online and study those. If you do that pretty soon you'll learn the ropes.

The NSMutableDictionary retains objects added to the dictionary. When the objects are removed they are released. As a result, removing an object from the dictionary accesses the object. If you have previously released the object and it is dealloc'ed, then this can cause an exception to be raised. If you examine the state of the object prior to removing from the dictionary you will likely see that it has already been released and dealloced.