IDChanged

Sent to an image when its ID property is changed.

# Metadata

Platforms: desktop, server, mobile OS: mac, windows, linux, ios, android Introduced: 1.0 Security:

# Syntax

IDChanged pOldID, pNewID

# Params

- pOldID : The image's original ID number. - pNewID : The image's new ID number.

# Examples

on IDChanged prevID,currentID -- update ID stored in another object set the storedID[the short name of image ID prevID] of this stack \ to currentID end IDChanged

# Description

Handle the IDChanged message if you want to make updates when an image ID is changed.

The ID property of most objects is set when the object is created and cannot be changed. There are two exceptions:stacks and images.

You can set the ID of an image to any positive integer. Be careful not to set an image ID to a number that's the ID of another image in the same stack : since LiveCode uses IDs to keep track of objects, a conflict may result in the inability to access one or both objects. The following ID numbers are reserved and should not be used for image IDs:

* 1-100: reserved for built-in cursors * 101-135: reserved for built-in brush shapes * 236-300: reserved for built-in patterns * 301-1000: reserved for built-in icons * 101,000-103,000: reserved * 200,000-299,999: reserved for application use

The actual change is not triggered by the IDChanged message, so trap the message and not allowing it to pass does not prevent the ID from being changed.

# Tags

objects,

# See

- **property:** altID, ID - **message:** nameChanged - **keyword:** image, integer - **object:** stack, image - **function:** stacks - **glossary:** object, property, trap, message, image - **control structure:** pass