C# Signature:

[DllImport("netapi32.dll", SetLastError=true, CharSet = CharSet.Unicode)]
static extern int NetFileClose(
    string servername,
    int id);

VB Signature:

Declare Unicode Function NetFileClose Lib "netapi32.dll"  _
     ByVal servername As String, _
     ByVal fileid As Integer) As Integer

User-Defined Types:

None.

Notes:

Definition from the API

    'NET_API_STATUS NetFileClose(
    '  LPWSTR servername,
    '  DWORD fileid
    ');

Tips & Tricks:

See NetFileEnum for how to get the fileid

C# Sample Code:

    if (MessageBox.Show(this, "Are you sure you want to close this connection?" == DialogResult.Yes))
        NetFileClose(strServerName, fileId);

VB.Net Sample Code:

    If MsgBox("Are you sure you want to disconnect this resource?", MsgBoxStyle.YesNo) = MsgBoxResult.Yes Then
        NetFileClose(strServerName, fileid)
    End If

Alternative Managed API:

Do you know one? Please contribute it!