Erasing the block will change the Handle ID for the object, and thus break this method. This means you can move a block anywhere you wish in the drawing (even a different Layout tab), but you cannot erase the block. No two objects in an AutoCAD drawing will have the same Handle ID, and the ID itself is designed to function as a unique identifier in the DWG database. Blocks are updated based on their Handle ID: Every object (including blocks) are assigned a unique Handle ID.Whislt the blocks can be anything you wish, there are a few tricks to using this method in production:
In the video above I demonstrate how to use these commands in tandem with Microsoft Excel to quickly renumber the room tags in a floor plan. Put simply, the commands will export Block Attribute values to a Tab-Delimited text file (ATTOUT), and update Block Attribute values from a Tab-Delimited text file (ATTIN). Two of my favorite Express Tool commands are ATTIN and ATTOUT. Although that wish has never been granted, the next best thing exists in the form of AutoCAD’s Express Tools. I’ve long wished AutoCAD had a command that would let you link a block to something like an Excel spreadsheet. Whilst it isn’t too difficult to update a couple of Block Attributes, when the blocks to update ventures beyond that – the task quickly becomes as tedious as it is time-consuming. Beyond the ubiquitous title block, Block Attributes are commonly used for Room Tags, to display calculations, and more. Block Attributes are an integral component of nearly every AutoCAD-based project I’ve worked on.