objective c - Storing Custom Object in NSMutableDictionary -

i trying store custom object in nsmutabledictionary. after saving when read object nsmutabledictionary it's null.

here code

//saving

nsmutabledictionary *dict = [[nsmutabledictionary alloc] init];  customobject *obj1 = [[customobject alloc] init]; obj1.property1 = @"my first property";  [dict setobject:obj1 forkey:@"firstobjectkey"]; [dict writetofile:[self datafilepath] atomically:yes]; 

// reading

 nsstring *filepath = [self datafilepath];         nsmutabledictionary *dict = [[nsmutabledictionary alloc] initwithcontentsoffile:filepath];          customobject *tempobj = [dict objectforkey:@"firstobjectkey"];          nslog(@"object %@", tempobj);         nslog(@"property1:%@,,tempobj.property1); 

how can store custom class object in nsmutabledictionary?

writetofile method can store standard types of objects plist. if have custom object you'd have use nskeyedarchiver/nskeyedunarchiver this.