how pass list from one form to another in C# winform?

Question

I have the following list on DisplayRooms form and same list(but not static) on the WalkinGuest form.

public static List<Room> RoomList

{get;set;}

public class Room

{

public int RoomID { get; set; }

public string RoomNumber { get; set; }

public string RoomType { get; set; }

}

List<Room> RoomsList = new List<Room>();

...

..

Now after insert data in RoomList I pass it to showwalkinform method then its give error..

showwalkinForm(RoomList);

private void showwalkinForm(List<Room> Rooms)

{

IxSolutionSuite.Forms.MDIMaster omdi = IxSolutionSuite.Forms.MDIMaster.Instance;

WalkinGuest oFrmWalkinGuest = WalkinGuest.Instance;

oFrmWalkinGuest.RoomList = (List<WalkinGuest.Room>)Rooms; //here it gives error:- can't convert type ... to ...

oFrmWalkinGuest.Show();

oFrmWalkinGuest.Focus();

}

Can any one tell help me to solve this problem..

Vulpes · Answer

No you just have the one Room class (at least I hope you do) whose qualified name is DisplayRooms.Room. All I'm saying is that you need to use this qualified name when referrring to the Room class from outside the DisplayRooms form so the compiler can find it. Each form that uses the List will therefore need a field of type List . It would have been better IMO if you'd made Room a top level class (i.e. not nested) in the same namespace as your forms. You could then simply have referred to it as 'Room' in all those forms but if you don't want to change anything you can't do that now.

Vikas Ahlawat · Answer

yes! we can use DisplayRooms.Room as a global class so... My problem is solved thnx very much Vulpes have you facebook account? I want to add you..

Vikas Ahlawat · Answer

I appreciate your thoughts ! fb and twitter are waste of time..

Vulpes · Answer

Sorry Vikas I don't have Facebook or Twitter accounts as I've never been too keen on the social networking sites. What thoughts I do have I tend to express on here :)

Vikas Ahlawat · Answer

ok but  am I need to declare list for every form? in WalkinGuest form like public List RoomList = null; // no need to create a new List here public List RoomList1 = null; public List Form1 .Room> RoomList2 = null; ??

Vulpes · Answer

In that case you'll always need to refer to it as the DisplayRooms.Room class in other forms and classes within the application. So your WalkinGuest form should be coded like this: public List RoomList = null; // no need to create a new List here and the showwalkinForm method (which I assume is on the DisplayRooms form) as follows: private void showwalkinForm(List Rooms) { IxSolutionSuite.Forms.MDIMaster omdi = IxSolutionSuite.Forms.MDIMaster.Instance; WalkinGuest oFrmWalkinGuest = WalkinGuest.Instance; oFrmWalkinGuest.RoomList = Rooms; // no need for a cast here oFrmWalkinGuest.Show(); oFrmWalkinGuest.Focus(); }

Vikas Ahlawat · Answer

It is nested within DisplayRooms class

Vulpes · Answer

Where is the Room class defined? Is it a 'top level' class or is it nested within the DisplayRooms form?

Vikas Ahlawat · Answer

@Vulpes thnx for reply I have already done coding for that and not want to change... because we redirect to WalkinGuest form from may other forms and every for this we need to create every form object... and switch case.. it req. many changes ........... So I don't want to access using DisplayRooms.RoomList Before this I was using simple list like List RoomList = new List (); then there was no error but when I start using public static List Room > RoomList { get ; set ; } public class Room { public int RoomID { get ; set ; } public string RoomNumber { get ; set ; } public string RoomType { get ; set ; } } then error occured.

Vulpes · Answer

If RoomList is a public static field of the DisplayRooms form then you don't actually need to pass it to any other form or class in the application - it's automatically available to them using the expression DisplayRooms.RoomList.

how pass list<> from one form to another in C# winform?