Hi.  I've a small problem with adding and removing nodes on a treeview on the client and then persisting the changes on a postback, using the ClientChanges property.  For the most part, it works as expected, I can Insert, Edit and Remove nodes and process the changes on the server.  However, the issue arises if I Insert a node, then Remove it and then try to save the changes.

In the ClientChanges collection, there are ClientOperation items representing both the Insert and the Remove, which, despite being inefficient, should still work.  As part of the Insert operation, I am capturing the index property of the node but this throws a NullReferenceException due to, I'm guessing the *pending* Remove operation.

I thought I was maybe using the trackChanges / commitChanges incorrectly and that if instead tracking and committing each operation...

// psuedo code

trackChanges();

insertNode();

commitChanges();

trackChanges();

removeNode();

commitChanges();

...I enabled tracking, performed all my edits and then commited changes, like this

// psuedo code

trackChanges();

insertNode();

removeNode();

commitChanges();

...then it might be smart enough to figure out that net effect is no change.  I implemented this but the same problem exists.

Can anyone shed any light on how to

• Retrieve the index on a node that is subject to a pending Remove operation or
• Cancel the add operation for a node thatis subject to a pending Remove operation

Thanks,

Keith.

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