C# Signature:

[DllImport("shlwapi.dll", SetLastError=true)]
static extern int PathCreateFromUrl([In]string url, [Out] StringBuilder path, [In,Out]ref uint pathLength, [In]uint reserved);

VB Signature:

    Declare Unicode Function PathCreateFromUrl Lib "shlwapi.dll" Alias "PathCreateFromUrlW" _
    (ByVal url As String, _
     ByVal path As System.Text.StringBuilder, _
     ByRef pathLength As System.UInt32, _
     ByVal reserved As Integer _
    ) As Integer

User-Defined Types:

None.

Alternative Managed API:

    Dim myUri As String = "file:///C|/Temp/foo.txt"
    Dim myResult As String = (new System.Uri(myUri)).LocalPath 'returns "C:\Temp\foo.txt"

Notes:

The pathLength will be at most MAX_PATH (defined in WinDef.h).

Returns an HRESULT.

Tips & Tricks:

Please add some!

Sample Code (VB winform):

    Const MAX_PATH As Integer = 260

    Private Sub pathFromUrlButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles pathFromUrlButton.Click
      Dim sz As System.UInt32
      Dim sb As System.Text.StringBuilder
      Dim rc As Integer

      sz = Convert.ToUInt32(INTERNET_MAX_URL_LENGTH)
      sb = New System.Text.StringBuilder(INTERNET_MAX_URL_LENGTH)

      rc = PathCreateFromUrl(urlTextbox.Text, sb, sz, 0)

      pathTextbox.Text = sb.ToString()
    End Sub