item types - expressions

RE: item types - expressions

Jon Summers — Thu, 13 May 2021 07:28:35 GMT

[quote userid="3229" url="~/products/microstation/f/microstation-forum/213792/item-types---expressions/649413"]I do not know haw to get the surface area for a shape[/quote]

It's an element property. This expression gets that property: this.GetElement().Area, where this means the Item Type instance and this.GetElement() retrieves the DGN element that owns the instance.

MasterPlanner uses the above as part of an expression to calculate the number of buildings per plot. Here's an example DGN file that contains an Item Type named MasterPlanner. The definition of property Building Count contains the expression ...

communities.bentley.com/.../MasterPlanner-01.dgn

[quote userid="3229" url="~/products/microstation/f/microstation-forum/213792/item-types---expressions/649413"]... no popup box appears...[/quote]

Now I'm confused. Your first screenshot shows a modal dialog.

RE: item types - expressions

RikR — Wed, 12 May 2021 19:14:03 GMT

.... no popup box appears.....

if I set " 1+1" in the expression area, then the expression is showing the result in the properties window,

but I do not know haw to get the surface area for a shape to calculate with.... so the builder is necessary

RE: item types - expressions

Jon Summers — Wed, 12 May 2021 15:43:28 GMT

The error message is complaining about array access. I agree that it could be more meaningful: the way it's written appeals only to programmers. However, you have set the Item Type property Is Array to false, so it's unclear why MicroStation popped that message.

Had you already started to edit the Expression? What happens when you click OK in that message box?