Create event for property update

Hi Swapnil,

I suggest you refer to the Programmer's Guide to get an overview of development in Aras. In it, you'll find examples on how to edit/update properties on Items using the .NET API and how to query for properties and connected Items.
For the examples you gave, the code could look something like this:

Edit a CAD Document:

// I'm assuming you have an Innovator object called inn
Item cadDocument = inn.newItem("CAD", "edit");
cadDocument.setID("idOfTheCadDocumentHere");
// Set the property you want to edit to its new value:
cadDocument.setProperty("name", "New Name");
Item editResult = cadDocument.apply();

Get the checked out file path of a file associated to a CAD Document:

Item cadDocument = inn.newItem("CAD", "get");
cadDocument.setID("idOfTheCadDocumentHere");
// Specify that you want to know the native_file's checkedout_path
cadDocument.setAttribute("select", "native_file(checkedout_path)");
Item getResult= cadDocument.apply();

There are multiple different ways to access this information, these are just two examples. Which one is best will depend on the specific use cases and setup in general. In any case, the Programmer's Guide is a good place to start (note that there are release-specific Programmer's Guides; the one I linked is for Innovator 12.0).

Hope this helps,

C