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How to Type cast ArrayList items to class objectsHi All,
I am new to vb .net, I have an ArrayList and i store class objects in it, and later i want to retrieve each ArrayList items and type cast to the class, How can it be done ? I used CType for casting but it is throwing exception. regards ludy buddy,
You mean something as \\\ dim myObject is myClass myArraylist.Add(myObject) DirectCast(myArrayList(0),myClass).WhatEver /// I hope this helps, Cor Show quoteHide quote "budy_ludy" <sent2a***@gmail.com> schreef in bericht news:1157041346.317762.139540@i42g2000cwa.googlegroups.com... > > Hi All, > > I am new to vb .net, > > I have an ArrayList and i store class objects in it, > and later i want to retrieve each ArrayList items and type cast to the > class, > How can it be done ? > I used CType for casting but it is throwing exception. > > > regards > ludy > Hi Cor
Below is the situation, I am trying to pass the arraylist from function1 to the function2 which accepts class, even if i type cast using Direct cast i get exception. Public class myClass Function1() ----------- dim myObject is myClass myArraylist.Add(myObject) Function2(myArraylist.Item(0)) ....... ....... ....... Function2(myClass ) ------------------- I get exception when i call Function2 inside Function1 even after DirectCast Cor Ligthert [MVP] wrote: Show quoteHide quote > buddy, > > You mean something as > \\\ > dim myObject is myClass > myArraylist.Add(myObject) > DirectCast(myArrayList(0),myClass).WhatEver > /// > I hope this helps, > > Cor > > > "budy_ludy" <sent2a***@gmail.com> schreef in bericht > news:1157041346.317762.139540@i42g2000cwa.googlegroups.com... > > > > Hi All, > > > > I am new to vb .net, > > > > I have an ArrayList and i store class objects in it, > > and later i want to retrieve each ArrayList items and type cast to the > > class, > > How can it be done ? > > I used CType for casting but it is throwing exception. > > > > > > regards > > ludy > > Hello budy_ludy,
What Exception exactly? -Boo Show quoteHide quote > Hi Cor > > Below is the situation, > I am trying to pass the arraylist from function1 to the function2 > which accepts class, > even if i type cast using Direct cast i get exception. > Public class myClass > > Function1() > ----------- > dim myObject is myClass > myArraylist.Add(myObject) > Function2(myArraylist.Item(0)) > ...... > ...... > ...... > Function2(myClass ) > ------------------- > I get exception when i call Function2 inside Function1 even after > DirectCast > > Cor Ligthert [MVP] wrote: > >> buddy, >> >> You mean something as >> \\\ >> dim myObject is myClass >> myArraylist.Add(myObject) >> DirectCast(myArrayList(0),myClass).WhatEver >> /// >> I hope this helps, >> Cor >> >> "budy_ludy" <sent2a***@gmail.com> schreef in bericht >> news:1157041346.317762.139540@i42g2000cwa.googlegroups.com... >> >>> Hi All, >>> >>> I am new to vb .net, >>> >>> I have an ArrayList and i store class objects in it, >>> and later i want to retrieve each ArrayList items and type cast to >>> the >>> class, >>> How can it be done ? >>> I used CType for casting but it is throwing exception. >>> regards >>> ludy Try this (I think this is what you meant).
Public class myClass .... End Class Function1() Dim myObject as myClass myArraylist.Add(myObject) dim myFunctionReturn as boolean myFunctionReturn = Function2(DirectCast(myArraylist.Item(0), myclass)) ...... End Function Function2(myVariable as myClass ) as boolean End Function > ------------------- -- Show quoteHide quoteDennis in Houston "budy_ludy" wrote: > Hi Cor > > Below is the situation, > I am trying to pass the arraylist from function1 to the function2 > which accepts class, > even if i type cast using Direct cast i get exception. > > > Public class myClass > > Function1() > ----------- > dim myObject is myClass > myArraylist.Add(myObject) > > Function2(myArraylist.Item(0)) > ....... > ....... > ....... > > > Function2(myClass ) > ------------------- > > I get exception when i call Function2 inside Function1 even after > DirectCast > > > > > Cor Ligthert [MVP] wrote: > > buddy, > > > > You mean something as > > \\\ > > dim myObject is myClass > > myArraylist.Add(myObject) > > DirectCast(myArrayList(0),myClass).WhatEver > > /// > > I hope this helps, > > > > Cor > > > > > > "budy_ludy" <sent2a***@gmail.com> schreef in bericht > > news:1157041346.317762.139540@i42g2000cwa.googlegroups.com... > > > > > > Hi All, > > > > > > I am new to vb .net, > > > > > > I have an ArrayList and i store class objects in it, > > > and later i want to retrieve each ArrayList items and type cast to the > > > class, > > > How can it be done ? > > > I used CType for casting but it is throwing exception. > > > > > > > > > regards > > > ludy > > > > > Hi,
sorry if i have not communicated properly earlier, Exact situation, C# I have a Library created in C# and it has a class myClass(only integers and strings), i store the objects in ArrayList. VB i call the Library in VB and it returns me the ArrayList(items of myClass objects), i retrieve the first element and typecast it to myClass, which has the same definition in both vb and c# (the class has only integers and string as elements and no methods) Same class definition in vb and c#(library) now at the point when i try to type cast ArrayList element to myClass in vb, it gives me below exception, ---------------------------- Unable to cast object of type Library.myClass to type myClass When casting from a number, the value must be a number less than infinity Make sure the source type is convertible to the destination type ---------------------------- i tried both DirectCast and also CType but it gives me exception any other alternative, if it is not possible to communicate class from c# library to vb ? Dennis wrote: Show quoteHide quote > Try this (I think this is what you meant). > > Public class myClass > .... > End Class > > Function1() > Dim myObject as myClass > myArraylist.Add(myObject) > dim myFunctionReturn as boolean > myFunctionReturn = Function2(DirectCast(myArraylist.Item(0), myclass)) > ...... > End Function > > Function2(myVariable as myClass ) as boolean > > End Function > > ------------------- > > -- > Dennis in Houston > > > "budy_ludy" wrote: > > > Hi Cor > > > > Below is the situation, > > I am trying to pass the arraylist from function1 to the function2 > > which accepts class, > > even if i type cast using Direct cast i get exception. > > > > > > Public class myClass > > > > Function1() > > ----------- > > dim myObject is myClass > > myArraylist.Add(myObject) > > > > Function2(myArraylist.Item(0)) > > ....... > > ....... > > ....... > > > > > > Function2(myClass ) > > ------------------- > > > > I get exception when i call Function2 inside Function1 even after > > DirectCast > > > > > > > > > > Cor Ligthert [MVP] wrote: > > > buddy, > > > > > > You mean something as > > > \\\ > > > dim myObject is myClass > > > myArraylist.Add(myObject) > > > DirectCast(myArrayList(0),myClass).WhatEver > > > /// > > > I hope this helps, > > > > > > Cor > > > > > > > > > "budy_ludy" <sent2a***@gmail.com> schreef in bericht > > > news:1157041346.317762.139540@i42g2000cwa.googlegroups.com... > > > > > > > > Hi All, > > > > > > > > I am new to vb .net, > > > > > > > > I have an ArrayList and i store class objects in it, > > > > and later i want to retrieve each ArrayList items and type cast to the > > > > class, > > > > How can it be done ? > > > > I used CType for casting but it is throwing exception. > > > > > > > > > > > > regards > > > > ludy > > > > > > > > budy_ludy,
In your VB project, is your myClass object dimensioned as a new instance of Library.myClass? Or do you have 2 classes: Library.myClass and another myClass defined in your VB project? Kerry Moorman Show quoteHide quote "budy_ludy" wrote: > Hi, > > sorry if i have not communicated properly earlier, > > Exact situation, > > C# > I have a Library created in C# and it has a class myClass(only integers > and strings), > i store the objects in ArrayList. > > VB > i call the Library in VB and it returns me the ArrayList(items of > myClass objects), > i retrieve the first element and typecast it to myClass, which has the > same definition in > both vb and c# (the class has only integers and string as elements and > no methods) > Same class definition in vb and c#(library) > > now at the point when i try to type cast ArrayList element to myClass > in vb, it gives me below exception, > ---------------------------- > Unable to cast object of type Library.myClass to type myClass > > When casting from a number, the value must be a number less than > infinity > > Make sure the source type is convertible to the destination type > > ---------------------------- > > i tried both DirectCast and also CType but it gives me exception > > any other alternative, if it is not possible to communicate class from > c# library to vb ? > > > > > > Dennis wrote: > > Try this (I think this is what you meant). > > > > Public class myClass > > .... > > End Class > > > > Function1() > > Dim myObject as myClass > > myArraylist.Add(myObject) > > dim myFunctionReturn as boolean > > myFunctionReturn = Function2(DirectCast(myArraylist.Item(0), myclass)) > > ...... > > End Function > > > > Function2(myVariable as myClass ) as boolean > > > > End Function > > > ------------------- > > > > -- > > Dennis in Houston > > > > > > "budy_ludy" wrote: > > > > > Hi Cor > > > > > > Below is the situation, > > > I am trying to pass the arraylist from function1 to the function2 > > > which accepts class, > > > even if i type cast using Direct cast i get exception. > > > > > > > > > Public class myClass > > > > > > Function1() > > > ----------- > > > dim myObject is myClass > > > myArraylist.Add(myObject) > > > > > > Function2(myArraylist.Item(0)) > > > ....... > > > ....... > > > ....... > > > > > > > > > Function2(myClass ) > > > ------------------- > > > > > > I get exception when i call Function2 inside Function1 even after > > > DirectCast > > > > > > > > > > > > > > > Cor Ligthert [MVP] wrote: > > > > buddy, > > > > > > > > You mean something as > > > > \\\ > > > > dim myObject is myClass > > > > myArraylist.Add(myObject) > > > > DirectCast(myArrayList(0),myClass).WhatEver > > > > /// > > > > I hope this helps, > > > > > > > > Cor > > > > > > > > > > > > "budy_ludy" <sent2a***@gmail.com> schreef in bericht > > > > news:1157041346.317762.139540@i42g2000cwa.googlegroups.com... > > > > > > > > > > Hi All, > > > > > > > > > > I am new to vb .net, > > > > > > > > > > I have an ArrayList and i store class objects in it, > > > > > and later i want to retrieve each ArrayList items and type cast to the > > > > > class, > > > > > How can it be done ? > > > > > I used CType for casting but it is throwing exception. > > > > > > > > > > > > > > > regards > > > > > ludy > > > > > > > > > > > > > Hi Kerry Moorman ,
i have a scenario like this, ....... vb ---- ArrayList inarray,outarray outarray = LibraryFunction(inarray) vbobject = new myClass vbobject.Function1( DirectCast(outarray.Item(0), myClass) ) and now i understood that there is one function, Function1 in myClass of vb, and the same function i have not defined in c#. In vb i call the Function1 and pass the items from ArrayList, and i get exception when i call Function1 , should i have a dummy function1 in c# library class ? Kerry Moorman wrote: Show quoteHide quote > budy_ludy, > > In your VB project, is your myClass object dimensioned as a new instance of > Library.myClass? > > Or do you have 2 classes: Library.myClass and another myClass defined in > your VB project? > > Kerry Moorman > > > "budy_ludy" wrote: > > > Hi, > > > > sorry if i have not communicated properly earlier, > > > > Exact situation, > > > > C# > > I have a Library created in C# and it has a class myClass(only integers > > and strings), > > i store the objects in ArrayList. > > > > VB > > i call the Library in VB and it returns me the ArrayList(items of > > myClass objects), > > i retrieve the first element and typecast it to myClass, which has the > > same definition in > > both vb and c# (the class has only integers and string as elements and > > no methods) > > Same class definition in vb and c#(library) > > > > now at the point when i try to type cast ArrayList element to myClass > > in vb, it gives me below exception, > > ---------------------------- > > Unable to cast object of type Library.myClass to type myClass > > > > When casting from a number, the value must be a number less than > > infinity > > > > Make sure the source type is convertible to the destination type > > > > ---------------------------- > > > > i tried both DirectCast and also CType but it gives me exception > > > > any other alternative, if it is not possible to communicate class from > > c# library to vb ? > > > > > > > > > > > > Dennis wrote: > > > Try this (I think this is what you meant). > > > > > > Public class myClass > > > .... > > > End Class > > > > > > Function1() > > > Dim myObject as myClass > > > myArraylist.Add(myObject) > > > dim myFunctionReturn as boolean > > > myFunctionReturn = Function2(DirectCast(myArraylist.Item(0), myclass)) > > > ...... > > > End Function > > > > > > Function2(myVariable as myClass ) as boolean > > > > > > End Function > > > > ------------------- > > > > > > -- > > > Dennis in Houston > > > > > > > > > "budy_ludy" wrote: > > > > > > > Hi Cor > > > > > > > > Below is the situation, > > > > I am trying to pass the arraylist from function1 to the function2 > > > > which accepts class, > > > > even if i type cast using Direct cast i get exception. > > > > > > > > > > > > Public class myClass > > > > > > > > Function1() > > > > ----------- > > > > dim myObject is myClass > > > > myArraylist.Add(myObject) > > > > > > > > Function2(myArraylist.Item(0)) > > > > ....... > > > > ....... > > > > ....... > > > > > > > > > > > > Function2(myClass ) > > > > ------------------- > > > > > > > > I get exception when i call Function2 inside Function1 even after > > > > DirectCast > > > > > > > > > > > > > > > > > > > > Cor Ligthert [MVP] wrote: > > > > > buddy, > > > > > > > > > > You mean something as > > > > > \\\ > > > > > dim myObject is myClass > > > > > myArraylist.Add(myObject) > > > > > DirectCast(myArrayList(0),myClass).WhatEver > > > > > /// > > > > > I hope this helps, > > > > > > > > > > Cor > > > > > > > > > > > > > > > "budy_ludy" <sent2a***@gmail.com> schreef in bericht > > > > > news:1157041346.317762.139540@i42g2000cwa.googlegroups.com... > > > > > > > > > > > > Hi All, > > > > > > > > > > > > I am new to vb .net, > > > > > > > > > > > > I have an ArrayList and i store class objects in it, > > > > > > and later i want to retrieve each ArrayList items and type cast to the > > > > > > class, > > > > > > How can it be done ? > > > > > > I used CType for casting but it is throwing exception. > > > > > > > > > > > > > > > > > > regards > > > > > > ludy > > > > > > > > > > > > > > > > > > budy_ludy wrote:
Show quoteHide quote > vb You have TWO classes? Once in a .vb file in your vb project and> ---- > ArrayList inarray,outarray > outarray = LibraryFunction(inarray) > > vbobject = new myClass > vbobject.Function1( DirectCast(outarray.Item(0), myClass) ) > > > and now i understood that there is one function, Function1 in myClass > of vb, > and the same function i have not defined in c#. > In vb i call the Function1 and pass the items from ArrayList, > and i get exception when i call Function1 , > should i have a dummy function1 in c# library class ? > another defined in a .dll written in C#? Is that correct? If so, then you can't do that. Even if your class in VB was identical to the class in C#, they are still considered different types by the runtime and you cannot cast between them. Just use the class in the C# library and don't try to duplicate it in VB and you should be ok. Chris Chris Dunaway,
which means i cannot cast a c# class to vb class even though they share same structure, ok got it, Chris Dunaway wrote: Show quoteHide quote > budy_ludy wrote: > > vb > > ---- > > ArrayList inarray,outarray > > outarray = LibraryFunction(inarray) > > > > vbobject = new myClass > > vbobject.Function1( DirectCast(outarray.Item(0), myClass) ) > > > > > > and now i understood that there is one function, Function1 in myClass > > of vb, > > and the same function i have not defined in c#. > > In vb i call the Function1 and pass the items from ArrayList, > > and i get exception when i call Function1 , > > should i have a dummy function1 in c# library class ? > > > > You have TWO classes? Once in a .vb file in your vb project and > another defined in a .dll written in C#? Is that correct? > > If so, then you can't do that. Even if your class in VB was identical > to the class in C#, they are still considered different types by the > runtime and you cannot cast between them. > > Just use the class in the C# library and don't try to duplicate it in > VB and you should be ok. > > Chris Well, umm, yeah, that is correct I guess.
However, I think you're missing the point: *Any* class you create in C# is perfectly usuable from VB and vice versa. If you defined myClass in your C# project then use that class from your VB project. Don't create a new class with the same name. A class is never the same as another class even though they might have the same name. /claes Show quoteHide quote "budy_ludy" <sent2a***@gmail.com> wrote in message news:1157117750.053169.126500@e3g2000cwe.googlegroups.com... > > Chris Dunaway, > > which means i cannot cast a c# class to vb class even though they share > same structure, > > ok got it, > > > budy_ludy wrote:
> Chris Dunaway, Exactly. Just use the C# class and add the function that you need to> > which means i cannot cast a c# class to vb class even though they share > same structure, that or if you need it in VB or cannot alter the C# class, then in your VB class, just inherit from the C# class then you can add your function in VB plus you will be able to cast from the C# class to the VB class. ok got the point, i will reuse the vb class in c# and from the c#
library i will return the class object and in vb i will type cast the returned arraylist item to vb class. Thank you to all. Chris Dunaway wrote: Show quoteHide quote > budy_ludy wrote: > > Chris Dunaway, > > > > which means i cannot cast a c# class to vb class even though they share > > same structure, > > Exactly. Just use the C# class and add the function that you need to > that or if you need it in VB or cannot alter the C# class, then in your > VB class, just inherit from the C# class then you can add your function > in VB plus you will be able to cast from the C# class to the VB class. budy,
I don't see the problem as long as you have set a reference to your C# class and that is correct CLS compliant written. Than the code should be the same as in my first message. The only thing is that in that I have used Whatever, because I don't know what properties/methods you have in that C# class. I hope this helps, Cor Show quoteHide quote "budy_ludy" <sent2a***@gmail.com> schreef in bericht news:1157101426.522310.17740@e3g2000cwe.googlegroups.com... > Hi, > > sorry if i have not communicated properly earlier, > > Exact situation, > > C# > I have a Library created in C# and it has a class myClass(only integers > and strings), > i store the objects in ArrayList. > > VB > i call the Library in VB and it returns me the ArrayList(items of > myClass objects), > i retrieve the first element and typecast it to myClass, which has the > same definition in > both vb and c# (the class has only integers and string as elements and > no methods) > Same class definition in vb and c#(library) > > now at the point when i try to type cast ArrayList element to myClass > in vb, it gives me below exception, > ---------------------------- > Unable to cast object of type Library.myClass to type myClass > > When casting from a number, the value must be a number less than > infinity > > Make sure the source type is convertible to the destination type > > ---------------------------- > > i tried both DirectCast and also CType but it gives me exception > > any other alternative, if it is not possible to communicate class from > c# library to vb ? > > > > > > Dennis wrote: >> Try this (I think this is what you meant). >> >> Public class myClass >> .... >> End Class >> >> Function1() >> Dim myObject as myClass >> myArraylist.Add(myObject) >> dim myFunctionReturn as boolean >> myFunctionReturn = Function2(DirectCast(myArraylist.Item(0), >> myclass)) >> ...... >> End Function >> >> Function2(myVariable as myClass ) as boolean >> >> End Function >> > ------------------- >> >> -- >> Dennis in Houston >> >> >> "budy_ludy" wrote: >> >> > Hi Cor >> > >> > Below is the situation, >> > I am trying to pass the arraylist from function1 to the function2 >> > which accepts class, >> > even if i type cast using Direct cast i get exception. >> > >> > >> > Public class myClass >> > >> > Function1() >> > ----------- >> > dim myObject is myClass >> > myArraylist.Add(myObject) >> > >> > Function2(myArraylist.Item(0)) >> > ....... >> > ....... >> > ....... >> > >> > >> > Function2(myClass ) >> > ------------------- >> > >> > I get exception when i call Function2 inside Function1 even after >> > DirectCast >> > >> > >> > >> > >> > Cor Ligthert [MVP] wrote: >> > > buddy, >> > > >> > > You mean something as >> > > \\\ >> > > dim myObject is myClass >> > > myArraylist.Add(myObject) >> > > DirectCast(myArrayList(0),myClass).WhatEver >> > > /// >> > > I hope this helps, >> > > >> > > Cor >> > > >> > > >> > > "budy_ludy" <sent2a***@gmail.com> schreef in bericht >> > > news:1157041346.317762.139540@i42g2000cwa.googlegroups.com... >> > > > >> > > > Hi All, >> > > > >> > > > I am new to vb .net, >> > > > >> > > > I have an ArrayList and i store class objects in it, >> > > > and later i want to retrieve each ArrayList items and type cast to >> > > > the >> > > > class, >> > > > How can it be done ? >> > > > I used CType for casting but it is throwing exception. >> > > > >> > > > >> > > > regards >> > > > ludy >> > > > >> > >> > > | Same class definition in vb and c#(library) Ah! There's the rubThe "class definition" should only be in one language/library either VB or C#. Although they may have similar layouts, they are distinct as the CLR uses assembly, version, namespace & type name to identify a type. Seeing as the VB class is in a VB assembly & the C# class is in a C# assembly the runtime will consider them distinct types. One of the major benefits of .NET is its interoperability in that you can define the class once in C#, then use that class definition all your want in VB and visa versa. Provided the class is CLS compliant.... -- Show quoteHide quoteHope this helps Jay B. Harlow [MVP - Outlook] ..NET Application Architect, Enthusiast, & Evangelist T.S. Bradley - http://www.tsbradley.net "budy_ludy" <sent2a***@gmail.com> wrote in message news:1157101426.522310.17740@e3g2000cwe.googlegroups.com... | Hi, | | sorry if i have not communicated properly earlier, | | Exact situation, | | C# | I have a Library created in C# and it has a class myClass(only integers | and strings), | i store the objects in ArrayList. | | VB | i call the Library in VB and it returns me the ArrayList(items of | myClass objects), | i retrieve the first element and typecast it to myClass, which has the | same definition in | both vb and c# (the class has only integers and string as elements and | no methods) | Same class definition in vb and c#(library) | | now at the point when i try to type cast ArrayList element to myClass | in vb, it gives me below exception, | ---------------------------- | Unable to cast object of type Library.myClass to type myClass | | When casting from a number, the value must be a number less than | infinity | | Make sure the source type is convertible to the destination type | | ---------------------------- | | i tried both DirectCast and also CType but it gives me exception | | any other alternative, if it is not possible to communicate class from | c# library to vb ? | | | | | | Dennis wrote: | > Try this (I think this is what you meant). | > | > Public class myClass | > .... | > End Class | > | > Function1() | > Dim myObject as myClass | > myArraylist.Add(myObject) | > dim myFunctionReturn as boolean | > myFunctionReturn = Function2(DirectCast(myArraylist.Item(0), myclass)) | > ...... | > End Function | > | > Function2(myVariable as myClass ) as boolean | > | > End Function | > > ------------------- | > | > -- | > Dennis in Houston | > | > | > "budy_ludy" wrote: | > | > > Hi Cor | > > | > > Below is the situation, | > > I am trying to pass the arraylist from function1 to the function2 | > > which accepts class, | > > even if i type cast using Direct cast i get exception. | > > | > > | > > Public class myClass | > > | > > Function1() | > > ----------- | > > dim myObject is myClass | > > myArraylist.Add(myObject) | > > | > > Function2(myArraylist.Item(0)) | > > ....... | > > ....... | > > ....... | > > | > > | > > Function2(myClass ) | > > ------------------- | > > | > > I get exception when i call Function2 inside Function1 even after | > > DirectCast | > > | > > | > > | > > | > > Cor Ligthert [MVP] wrote: | > > > buddy, | > > > | > > > You mean something as | > > > \\\ | > > > dim myObject is myClass | > > > myArraylist.Add(myObject) | > > > DirectCast(myArrayList(0),myClass).WhatEver | > > > /// | > > > I hope this helps, | > > > | > > > Cor | > > > | > > > | > > > "budy_ludy" <sent2a***@gmail.com> schreef in bericht | > > > news:1157041346.317762.139540@i42g2000cwa.googlegroups.com... | > > > > | > > > > Hi All, | > > > > | > > > > I am new to vb .net, | > > > > | > > > > I have an ArrayList and i store class objects in it, | > > > > and later i want to retrieve each ArrayList items and type cast to the | > > > > class, | > > > > How can it be done ? | > > > > I used CType for casting but it is throwing exception. | > > > > | > > > > | > > > > regards | > > > > ludy | > > > > | > > | > > | 
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