C# Signature:

[DllImport("psapi")]
public static extern bool EmptyWorkingSet(IntPtr hProcess);

VB Signature:

Public Declare Function EmptyWorkingSet Lib "psapi.dll" (hwProc As IntPtr) As Int32

User-Defined Types:

None.

Alternative Managed API:

System.Diagnostics.Process.MaxWorkingSet and System.Diagnostics.Process.MinWorkingSet are similar but are used to set thresholds rather than just free whatever can be freed.

Notes:

Tips & Tricks:

Please add some!

Sample Code:

    public static bool TrimWSByProcess(Process process)
    {
        bool _result = false; //assume failed

        try
        {
            if (process != null)
            { //only continue if we have a process
                long _workingSet = process.WorkingSet64;

                //trim working set
                _result = PsapiHelper.EmptyWorkingSet(process.Handle);

                //check result
                if (_result)
                { //sucessfully trimed

                }
                else
                { //failed to trim

                }
            }
            else
            { //no process passed in

            }
        }
        catch (Exception ex)
        { //exception occured. Do some error handling
            _result = false;
            throw; //throw the error in this case.
        }

        return _result;
    }

Sample Code:

    Module Module1
        Sub Main()
    BackAgain:
            Dim MemEater$() = New String(-1){}
            ReDim MemEater(&O141231232)
            Dim Proc As Process = Process.GetCurrentProcess()
            Print("{0:N0} Mb", ((Proc.WorkingSet64 \ 1024) \ 1024))            
            Call EmptyWorkingSet(Process.GetCurrentProcess().Handle)
            Print("{0:N0} Mb", ((Proc.WorkingSet64 \ 1024) \ 1024)) : Print("")
            Console.Write("Back ? ""Y"" or ""No""")
            If Console.ReadLine().ToLower = "y" Then GoTo BackAgain Else Exit Sub
        End Sub

        Sub Print(format$, ParamArray args As Object)
            Console.WriteLine(format, args)
        End Sub
    End Module