Loading a Dataset asynchronously from SQL + VB.NET

A

aah_what

Member
Joined
Aug 18, 2003
Messages
7
Hi,

I would like to know if anyone knows how to load a dataset asynchronously and if anyone has an example.

I have tried using threading but when I move the form it gives an error - "OBJECT NOT SET TO AN INSTANCE OF AN OBJECT"

Is there anybody that can help with either of the problems? I am using windows forms and a sql backend.

Thanks

Matt
 
You can use a WebService which returns a DataSet. Use the Begin___ and End___ webservice methods to handle the data asyncronously. I dont think youll be able to do anything with the DataSet until its completely retrieved though. Meaning, you should call the End___ method in or before Form_Load.

If you want a more built-in asynchronous method of getting data, use a DataReader. You can always pump the data into a DataSet as its retreived if thats what you want.

-Ner
 
Hi,

I do not want to use a datareader or a web service. I want to load a dataset through a datadapter because the data in the dataset is going to be altered later and then updated.

Is there a way of doing this async?

Matt
 
Why is it so important to do this async? What are you trying to do while youre extracting the data???
 
Hi Derek,

Thanks, that sounds like what I want to do, do you have an example of the code to do it, please?

Matt
 
Hi Sam,

Maybe you can help me then, I had my app set up like this. It starts off with the mainform opening and then shows another form that loads with threads like you have. After a while and especialy if I move the form around or anything I get an error.

"OBJECT NOT SET TO AN INSTANCE OF AN OBJECT"

If it is in release mode, a thread error comes up and the program terminates.

Have you got any other Ideas?

Matt
 
Maybe you can link to a zip of your project here, then we can all have a look at it. (or email it, as long as its only a couple meg)
 
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