Display sample currecny values as both a Double .ToString and a well formatted string.
[C#]
/// <summary>
/// Display sample currecny values as both a Double .ToString and a well formatted string.
/// </summary>
/// <remarks></remarks>
public void CurrencyFormatExample()
{
  ESRI.ArcGIS.esriSystem.INumberFormat numberFormat = new ESRI.ArcGIS.esriSystem.CurrencyFormatClass();
  // Use the ValueToString method to format numbers. 
  System.Double double_UnformattedNumber = 0;
  System.String string_ValueToString = null;
  System.Double double_StringToValue = 0;
  for (double_UnformattedNumber = 100.567; double_UnformattedNumber <= 1000101; double_UnformattedNumber += 200000)
  {
	// ValueToString() returns a formatted string, but does not change the passed in numerical value
	string_ValueToString = numberFormat.ValueToString(double_UnformattedNumber);
	// StringToValue() translates formatted strings back to a numerical value
	double_StringToValue = numberFormat.StringToValue(string_ValueToString);
	System.Windows.Forms.MessageBox.Show("ValueToString(" + double_UnformattedNumber + ") = '" + string_ValueToString + "'" + System.Environment.NewLine + "StringToValue('" + string_ValueToString + "') = " + double_StringToValue, "CurrencyFormat");
  }
}
[Visual Basic .NET]
''' <summary>
''' Display sample currecny values as both a Double .ToString and a well formatted string.
''' </summary>
''' <remarks></remarks>
Sub CurrencyFormatExample()
  Dim numberFormat As ESRI.ArcGIS.esriSystem.INumberFormat = New ESRI.ArcGIS.esriSystem.CurrencyFormatClass
  ' Use the ValueToString method to format numbers. 
  Dim double_UnformattedNumber As System.Double
  Dim string_ValueToString As System.String
  Dim double_StringToValue As System.Double
  For double_UnformattedNumber = 100.567 To 1000101 Step 200000
    ' ValueToString() returns a formatted string, but does not change the passed in numerical value
    string_ValueToString = numberFormat.ValueToString(double_UnformattedNumber)
    ' StringToValue() translates formatted strings back to a numerical value
    double_StringToValue = numberFormat.StringToValue(string_ValueToString)
      System.Windows.Forms.MessageBox.Show("ValueToString(" + double_UnformattedNumber.ToString + ") = '" + string_ValueToString + "'" + System.Environment.NewLine + _
           "StringToValue('" + string_ValueToString + "') = " + double_StringToValue.ToString, "CurrencyFormat")
  Next
End Sub