Type: Integer
Availability: Read or write at development time, read-only at run time
The mdiChild property of the Form class specifies whether a form is displayed as an MDI child form inside an MDI frame form. Use this property when creating a Multiple Document Interface (MDI) application.
At run time, forms with this property set to MdiChild_IsMdi (2) are displayed inside an MDI form. An MDI child form can be maximized, minimized, and moved inside the parent MDI form (if the minButton and maxButton property values are true).
The settings of the mdiChild property are listed in the following table.
| Form Class Constant | Value | Description |
|---|---|---|
| MdiChild_UseAppDefault | 0 | Use the value of the |
| MdiChild_NotMdi | 1 | Form create results in a non-MDI form |
| MdiChild_IsMdi | 2 | Form create results in an MDI form |
The mdiChild property can then be used to provide the user with the choice of running the application as MDI forms when forms that do not specifically have to be MDI forms are assigned the default mdiChild property value.
Setting the application preference at startup time then runs those forms as MDI or standalone forms.
Set this property to a non-default value in the JADE development environment only if it is specifically required to run MDI or standalone forms. For example, forms shown modally must have a resulting mdiChild property value of MdiChild_NotMdi (1), otherwise the form could be created as MDI and then the modal status is ignored, as it cannot be converted after creation.
When working with MDI child forms, keep the following in mind.
At run time, when an MDI child form is given the focus, its caption is combined with that of the parent frame. Its menu also replaces the MDI form menu of the parent.
In the JADE development environment, an MDI child form is displayed like any other form, as the form is displayed inside the parent form only at run time.
MDI child forms cannot be modal. The showModal method on a form declared as an MDI child form raises an exception. For more details, see "Windows Events and JADE Events", later in this document.
The Windows environment controls the placement of MDI child forms unless you specifically set the placement in the load event of the form.
The MDI frame form is automatically loaded for the first MDI child. If the MDI frame form is the default (supplied by jade.exe), it is unloaded when its last MDI child is unloaded.