Hey,

Can anybody please help me solve this little problem, I've been working on it for the past 3 days, I've googled and re-written the code, I'm getting the following error;

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error: LINE 269


Line 267:
Line 268: Sub Button1_Click(sender As Object, e As EventArgs)
Line 269: ServerSpec( _
Line 270: (DropDownList1.SelectedItem.Value), _
Line 271: (servercolour.SelectedItem.Value), _


I'll post code if required.

As always any suggestions and help greatly appreciated

D

This indicates that either one of the controls is not instantiated or that one of the controls does not have a selected item.

One thing to check is the condition under which you are loading the contents of those dropdownlists. If you are binding them on every page hit then when the button click handler fires, the list won't have a selected item, even though in the browser the DDL is sitting on the first item (because it has to, not because it is selected).

-Peter

Thanks Peter,
So what I have to do is to make sure that all my DDL's have a selected statement inserted.

D

Yes, the DDL will have to have a selected item but you don't have to explicitly select an item in the code-behind.

In normal behavior a drop down list will always have a selected item EXCEPT for the page execution where you bind the list then try to call SelectedItem on the DDL. That's why I suggested you check to see when the list is being databound. On any page hit after the first, as long as the list isn't being databound before you try to look at SelectedItem, the list will always have an item selected (even if it's the first item in the list).

-Peter

Hey Peter,
I've gone through every bit of my code I've made chages with the selected index value, and I'm still getting the same error. I don't know what else to do, I've re-written some of the code and I've re-written the database.

Without being able to debug the code myself, I don't know how else to help. Have you beeng able to see that values are being seen at the function call?

-Peter

Hey Peter,
Just wanted to say thanks for all your help, it turned out that I had a DDL hidden, silly me.

Sorry

D

Hummmmmm....

Seems like I haven't resolved this problem, if I wrote a Try....Catch Statement, would that help me rectify the exception?
Because when I'm writing to my database I have it so that Nulls are accepted, but when I click the save button I keep getting that error only when some fields are left blank.
So any idea how to write such a statement?? I've googled away, but I want it to happen on button click etc.

D

A try...catch won't necessarily help solve the problem, it may just mask it. It sounds like you need to do some extensive debugging to see how blank/null values are getting into the statement.

-Peter