I can tell its empty because dstMaster is null. I'm really stumped by this! Is there something I should do in the constructor for my class to initialize dstMaster? The only code I have for it is the declaration and the three lines of code to copy an existing dataset and merge two others in. And of course, the code to access the master which tests for null first.
Thanks, Karen Healey [EMAIL PROTECTED] ----- Original Message ----- From: "Ian Griffiths" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, May 29, 2002 16:56 Subject: Re: [DOTNET] why does DataSet have to be static meber > It sounds like it should be OK. If it's all the one form then it should be > the same instance. If you wanted to verify that you could print out the > value for GetHashcode() in both places. (Use something like > Debug.WriteLine, defined in the System.Diagnostics namespace.) If the > numbers are the same then that normally means the instance is the same > unless GetHashcode has been overridden (and for a form it won't have been, > unless you've overidden it yourself.) If the hash codes are different you > definitely have different instances. > > How are you determining that the DataSet is empty? (Is the dstMaster itself > null? Or is it non-null but referring to something that appears to have no > data in it?) > > > -- > Ian Griffiths > DevelopMentor > > ----- Original Message ----- > From: "Karen Healey" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Wednesday, May 29, 2002 10:49 PM > Subject: Re: [DOTNET] why does DataSet have to be static meber > > > > I'm sure the methods are executing in the correct order. But I'm not sure > > about it being the same instance. It seems to me it should be the same > > instance but I'm new to this. > > > > I have a multi-panel form (similating multiple pages). At the bottom of > one > > of the last panels made visible, I have a finish button. In the > > FinishButton_Click method, the current panel is hidden, another panel is > > made visible and the data set is built using the data member, dstMaster. > > Then the user is at the new panel and this panel has a submit button (the > > finish button is no longer visible). When the user clicks on the submit > > button, the SubmitButton_Click method tries to access dstMaster and its > > empty. Seems like it goes away as soon as the code exits the > > FinishButton_Click method. > > > > So, since this is all one form and no other forms are brought up (just a > > bunch of panels hidden/made visible) then it should be the same instance, > > right? > > > > Thanks, > > > > Karen Healey > > [EMAIL PROTECTED] > > > > ----- Original Message ----- > > From: "Ian Griffiths" <[EMAIL PROTECTED]> > > To: <[EMAIL PROTECTED]> > > Sent: Wednesday, May 29, 2002 16:38 > > Subject: Re: [DOTNET] why does DataSet have to be static meber > > > > > > > I have never had any problems using DataSets as non-static members. I > > > suspect that something slightly more subtle is going wrong. Are you > > > absolutely sure that (a) the methods are executing in the order you > think > > > they are and (b) that they are actually executing on the same instance > > both > > > times? > > > > > > > > > -- > > > Ian Griffiths > > > DevelopMentor > > > > > > ----- Original Message ----- > > > From: "Karen Healey" <[EMAIL PROTECTED]> > > > > > > > I've created a class in C# with a DataSet data member declared like > > this: > > > > > > > > private DataSet dstMaster; > > > > > > > > I have a method that builds it by concatenating three datasets > together > > > > like this: > > > > > > > > dstMaster = dstOrg.Copy(); > > > > dstMaster.Merge( dstContact ); > > > > dstMaster.Merge( dstFunding ); > > > > > > > > In a SEPARATE method, I try to access the contents of the dataset but > it > > > > is empty! > > > > > > > > If I declare the dataset as static, I don't have this problem. I > don't > > > > understand why this is necessary. > > > > > > > > If someone could explain this to me it would be appreciated. > > > > > > You can read messages from the DOTNET archive, unsubscribe from DOTNET, > or > > > subscribe to other DevelopMentor lists at http://discuss.develop.com. > > > > > > > You can read messages from the DOTNET archive, unsubscribe from DOTNET, or > > subscribe to other DevelopMentor lists at http://discuss.develop.com. > > > > You can read messages from the DOTNET archive, unsubscribe from DOTNET, or > subscribe to other DevelopMentor lists at http://discuss.develop.com. > You can read messages from the DOTNET archive, unsubscribe from DOTNET, or subscribe to other DevelopMentor lists at http://discuss.develop.com.
