Where o' where has my "HasChanges() gone"?

Hiya,

I have a windows form displaying a dataset from a select query and I am trying to find a way to determine when my datset has changed so I can pop a message box when the naviagte to a different record or close the form asking the user if he/she would like to save. I came across the HasChanges() method which seemed like a grand idea but when I try it like:

if (myDataset.HasChanges())
{
pop me a MessageBox() to save or discard;
}

else

{
....just keep on rolling;
}

......my app will not build explaining that I am missing an object reference and as expected, when I press the . to the right of the dataset there is no haschanges method available. The system.data reference is there, hence I am baffled. I am using C# with Visual Studio 2005 with a pretty generic set of TableAdapters and generic SQL Select statements. Can someone help me here

J.H.

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Where o' where has my "HasChanges() gone"?

Meta
Ya, no kidding! I did notice a difference in the case of the type. MyDataSet and mydataset are indeed two completely different objects.

Thanks for noticing.

J.H.
Sergey Karimov
A-Hah! I was correct in my assumption that .net is indeed creating the datasets for me and instantiating them. My oversite was a simple lack of adding "this" to my call. Should be....

if (this.mydataset.HasChanges())

Works like a charm...Thanks anyhoo.

J.H.
abzz

Just a stab in the dark...is it boolean

if (myDataset.HasChanges() = True)

---edited---oops sorry...you already figured it out...lol

Adamus
dajeeper
Well, maybe I am confused about something here. Doesn't C# create this dataset for me when the application runs the select statement I can see my data in the form, I can navigate it and change it without doing any saves, deletes, or updates back to the database. Isn't this existing dataset accessible without instantiating and filling another one I am presuming, perhaps wrong, that this class is already being created and filled for me...Can someone clarify

J.H.
Javalier
You are sure that you've created an instance of DataSet that is called myDataSet , and you're also sure that this object is 'accessible' within the scope where you call the HasChanges() method
NoviceGeek

Hi,

Just a note that this doesn't solve anything in this case. Your problem was casing of mydataset - mydataset is an instance while myDataset is a type in your case I assume.

Thus even dropping this should work if you write mydataset.
Where o' where has my "HasChanges() gone"?

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