Use the .NET framework to shorten a path string with an ellipsis

''' <summary>
''' Truncates a file path to fit within a given pixel width by replacing path components with ellipses.
''' </summary>
''' <param name="hdc">[in] A handle to the device context used for font metrics.</param>
''' <param name="lpszPath">[in, out] A pointer to a null-terminated string of length MAX_PATH that contains the path to be modified. On return, this buffer will contain the modified string.</param>
''' <param name="dx">[in] The width, in pixels, in which the string must fit.</param>
''' <returns>Returns TRUE if the path was successfully compacted to the specified width. Returns FALSE on failure, or if the base portion of the path would not fit the specified width.</returns>
''' <remarks>
''' <para>This Shell Lightweight Utility function uses the font currently selected in hDC to calculate the width of the text. This function will not compact the path beyond the base file name preceded by ellipses.</para>
''' <para>The .NET Framework version 2.0 contains the TextRenderer.MeasureText method, which can reproduce the functionality of the PathCompactPath function, as shown in the following example.</para>
''' <example>
''' <code>
'''    Public Function CompactPath(ByVal text As String, ByVal control As Control) As String
''' 
'''        'make a copy because the measure text call is instructed to modify string
'''        Dim sResult As String = String.Copy(text)
''' 
'''        TextRenderer.MeasureText(sResult, control.Font, control.ClientSize, TextFormatFlags.PathEllipsis Or TextFormatFlags.ModifyString)
'''  
'''        Return sResult
''' 
'''    End Function
''' </code>
''' </example>
''' </remarks>
<Obsolete("In .NET 2.0, use TextRenderer.MeasureText with TextFormatFlags.PathEllipsis", True)> _
Declare Auto Function PathCompactPath Lib "shlwapi.dll" ( _
    ByVal hdc As IntPtr, _
    ByVal lpszPath As System.Text.StringBuilder, _
    ByVal dx As Int32) As Boolean
 
''' <summary>
''' Truncates a file path to fit within a given pixel width by replacing path components with ellipses.
''' </summary>
''' <returns>Returns the path compacted to the specified width. This function will not compact the path beyond the base file name preceded by ellipses. Therefore, the base portion of the path may not always fit within the specified width.</returns>
''' <remarks>
''' <para>Works well with monospace/fixed-width fonts. Tends to compact text too much when using proportional fonts.</para>
''' </remarks>
Public Function CompactPath(ByVal path As String, ByVal control As Control) As String
    Const MAX_PATH As Integer = 260
 
    Dim oPath As New System.Text.StringBuilder(path, MAX_PATH)
    Dim oGraphics As System.Drawing.Graphics = control.CreateGraphics
 
    Try
 
        If PathCompactPath(oGraphics.GetHdc, oPath, control.ClientSize.Width) Then
            'okay
        Else
            'failure or base name too long for specified width
        End If
 
    Finally
 
        If Not (oGraphics Is Nothing) Then
 
            'if you do not release the device context then you will get
            '   An unhandled exception of type 'System.InvalidOperationException' occurred in system.drawing.dll
            '   The object is currently in use elsewhere.
 
            oGraphics.ReleaseHdc()
            oGraphics.Dispose()
 
        End If
 
    End Try
 
    Return oPath.ToString
End Function

    Public Function ShrinkString(ByVal strString As String, ByVal intWidth As Integer, ByVal Font As Drawing.Font, ByVal FormatFlags As Windows.Forms.TextFormatFlags) As String

        Dim strWorking As String = String.Copy(strString)
        Dim strResult As String = ""
        Dim charResult As Char = ""

        TextRenderer.MeasureText(strWorking, Font, New Drawing.Size(intWidth, 0), FormatFlags Or TextFormatFlags.ModifyString)

        For Each charResult In strWorking
            If charResult = Nothing Then
                Exit For
            End If
            strResult &= charResult
        Next

        Return strResult

    End Function