WPF - 使用ObserableCollections更新现有的ROW值而不是DataGrid中的新Row

I'm new to WPF and I'm trying to learn the basic things to build a simple tool for a time saving purpose. Here I'm trying to read a remote file to get the status and updating the datagrid with machine name and status of the file. I'm new to WPF and I'm trying to learn the basi