8/17/2019 Preventing the User From Closing a VI During Execution - National Instruments

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Preventing the User From Closing a VI During Execution

Primary Software: LabVIEW Development Systems>>LabVIEW Full Development System

Primary Software Version: 8.0

Primary Software Fixed Version: N/A

Secondary Software: N/A

Problem:

I would like to prevent users from closing the front panel of my application when it is running. How can I

do this?

Solution:

There are two ways to prevent the user from closing the front panel of your application when it is

running: using an event structure or modifying the title bar.

Using an Event Structure

When the user closes the front panel of an application in LabVIEW, an event structure can capture theevent with the Panel Close?  event and discard the event, allowing the window to remain open. The

Panel Close?  event is a filter event which notifies you that the user has performed an action before

LabVIEW processes it. This allows you to modify the default behavior of the event. In the case of the

Panel Close?  filter event, you can discard the panel close action by wiring a True constant to the

Discard? filter node on the right side of the event structure.

Modifying the Title Bar 

You can prevent the user from closing the application by removing the title bar or selectively disabling

the buttons.

To hide the title bar, perform the following steps:

Go to File»VI Properties.1.

Choose the Window Appearance category.2.

Click Customize.3.Uncheck Window has title bar.4.

To programmatically hide the title bar, set the Front Panel: Title Bar Visible  property.

To disable the ability to allow the user to close the window but keep the title bar, perform the following

steps:

Go to File»VI Properties.1.

Choose the Window Appearance category.2.

Click Customize.3.

Uncheck Allow user to close window.4.

Related Links:NI Community: Prevent Front Panel Close Using Event Structures

Example Program: Use the Event Structure in LabVIEW to Capture a Panel Close Event

LabVIEW Help: Customize Window Appearance Dialog Box

LabVIEW Help: Front Panel Window:Title Bar Visible Property

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