如何访问子窗体上的文本框控件的值，其中子窗体本身只是主窗体的另一个子窗体上的控件

Question

I've just assumed responsibility for a database written ages ago in MS Access and I need to make some changes but unfortunately, even though I used to be a very experienced Access developer some time ago, I haven't really used it to an advanced level for about 15 years and I just can't work out how to do what I need.

Specifically, I have a main form called frmOrders. On that form I have a subform called frmJobCard. But frmJobCard is itself a form with a subform called frmSFJCOrders. So, when someone clicks a particular button on frmOrders, I need to be able to read the value of a textbox on frmSFJCOrders and take action based on that value.

I've so far read through dozens of posts (both on StackOverflow and other techy sources) all of which touch upon different aspects of reading from controls on subforms and I've spent over a day trying to get this right but it never actually works so I'd be grateful if someone could tell me how I just read this value.

I think I need something along the lines of...

If Forms.frmOrders.frmJobCard.Form.frmSFJCOrders.[Estimate QTY] = 0 Then

...but I just can't make it work.

I would expect the code above to evaluate to 0 then take the actions below but it just always fails on the evaluation with

Run-time error '2465': Application-defined or object-defined error

Any help is greatly appreciated - thanks in advance :)

Answer 1

Consider this Access MVPs resource which I bookmarked in my early Access programming days. Specifically you need ! to delineate within objects and . to delineate between parent/child objects with Form. qualifier for every form object.

If Forms!frmOrders!frmJobCard.Form!frmSFJCOrders![Estimate QTY] = 0 Then

Alternatively, use a functional version:

If Forms("frmOrders").Controls("frmJobCard") _
                     .Controls("frmSFJCOrders") _
                     .Controls("[Estimate QTY]") = 0 Then

Answer 2

It should be close to this:

If Me!frmJobCard.Form!frmSFJCOrders.Form![Estimate QTY].Value = 0 Then

Note that frmJobCard and frmSFJCOrders must be names of the subform controls which may differ from the names of the forms.