WPF Binding - Changing property on one object in collection and all the objects are changing-CodePudding

When I change value of textbox or checkbox it changes in every line. Whats wrong? Here is an examplу: All checkboxes aren't checked. I click on one of them and all the other are now checked.

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Here is the code: enter image description here

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Adding position method: enter image description here

CodePudding user response：

The problem is because of the below line

spotPosition = AutoTradingPositions.Where(position => 
                          position.PositionNumber == latestPositionNumber).First();

Where you are getting the same instance (first item in the collection) and adding the same as other items to the collection.