'ObservableCollection' could not be found even when using 'System.Collections.ObjectModel'

c#, visual-studio, visual-studio-2012

Solution

You're probably missing an assembly reference... depending on which framework you are targeting, this class might be found:

- in WindowsBase.dll (.NET 3.x)

- in System.dll (.NET 4.x)

- in System.Windows.dll (Silverlight/Windows Phone 7)

- in System.ObjectModel.dll (WinRT) (included in ".NET for Windows Store apps")

Problem

`System.Collections.ObjectModel` is included. Visual studio 2012 still says `Type or namespace name 'ObservableCollection' could not be found.` Similar to this question Code: ``` class ObservableClass : ObservableCollection<OtherClass> { } ``` EDIT: This is .NET Framework 3.5 and is a console application

Original source

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