Cannot modify resource set without a write transaction 问题

TransactionalEditingDomainImpl editingDomain = (TransactionalEditingDomainImpl) diagramEditor.getEditingDomain();
        editingDomain.getCommandStack().execute(new RecordingCommand(editingDomain) {
            @Override
            protected void doExecute() {
            　　//do something
            }
        });

EMF中模型不能直接编辑，需要有事务，支持undo redo。