My understanding of the Command Pattern is that you simply have 1 virtual method ‘execute()’, and all dependencies that an implementation might have are put in the constructor or through setter injection in the implementation (like discussed here).
However, in the WPF implementation of the pattern, I noticed they are passing a generic argument to the execute() function (explained here).
This seems like a pollution of the interface to me, what would have been the motivation to add a generic parameter to the execute() function?
It’s for databinding. When you bind the command to every object in a list, for example, the current instance is sent to the execute method so that you don’t have to keep track of the current instance yourself.
That said, I don’t think that the WPF command notion is an implementation of the command pattern, they just share terminology.