IConvertible Interface

Defines methods that convert the value of the implementing reference or value type to a common language runtime type that has an equivalent value.

Module Example
 Public Class Complex
 Implements IConvertible
 Private x As Double
 Private y As Double
 Public Sub New(ByVal x As Double, ByVal y As Double)
 Me.x = x
 Me.y = y
 End Sub 'New
 Public Function GetTypeCode() As TypeCode Implements IConvertible.GetTypeCode
 Return TypeCode.Object
 End Function
 Function ToBoolean(ByVal provider As IFormatProvider) As Boolean Implements IConvertible.ToBoolean
 If x <> 0 Or y <> 0 Then
 Return True
 Else
 Return False
 End If
 End Function
 Function GetDoubleValue() As Double
 Return Math.Sqrt((x * x + y * y))
 End Function
 Function ToByte(ByVal provider As IFormatProvider) As Byte Implements IConvertible.ToByte
 Return Convert.ToByte(GetDoubleValue())
 End Function
 Function ToChar(ByVal provider As IFormatProvider) As Char Implements IConvertible.ToChar
 Return Convert.ToChar(GetDoubleValue())
 End Function
 Function ToDateTime(ByVal provider As IFormatProvider) As DateTime Implements IConvertible.ToDateTime
 Return Convert.ToDateTime(GetDoubleValue())
 End Function
 Function ToDecimal(ByVal provider As IFormatProvider) As Decimal Implements IConvertible.ToDecimal
 Return Convert.ToDecimal(GetDoubleValue())
 End Function
 Function ToDouble(ByVal provider As IFormatProvider) As Double Implements IConvertible.ToDouble
 Return GetDoubleValue()
 End Function
 Function ToInt16(ByVal provider As IFormatProvider) As Short Implements IConvertible.ToInt16
 Return Convert.ToInt16(GetDoubleValue())
 End Function
 Function ToInt32(ByVal provider As IFormatProvider) As Integer Implements IConvertible.ToInt32
 Return Convert.ToInt32(GetDoubleValue())
 End Function
 Function ToInt64(ByVal provider As IFormatProvider) As Long Implements IConvertible.ToInt64
 Return Convert.ToInt64(GetDoubleValue())
 End Function
 Function ToSByte(ByVal provider As IFormatProvider) As SByte Implements IConvertible.ToSByte
 Return Convert.ToSByte(GetDoubleValue())
 End Function
 Function ToSingle(ByVal provider As IFormatProvider) As Single Implements IConvertible.ToSingle
 Return Convert.ToSingle(GetDoubleValue())
 End Function
 Overloads Function ToString(ByVal provider As IFormatProvider) As String Implements IConvertible.ToString
 Return "( " + x.ToString() + " , " + y.ToString() + " )"
 End Function
 Function ToType(ByVal conversionType As Type, ByVal provider As IFormatProvider) As Object Implements IConvertible.ToType
 Return Convert.ChangeType(GetDoubleValue(), conversionType, provider)
 End Function
 Function ToUInt16(ByVal provider As IFormatProvider) As UInt16 Implements IConvertible.ToUInt16
 Return Convert.ToUInt16(GetDoubleValue())
 End Function
 Function ToUInt32(ByVal provider As IFormatProvider) As UInt32 Implements IConvertible.ToUInt32
 Return Convert.ToUInt32(GetDoubleValue())
 End Function
 Function ToUInt64(ByVal provider As IFormatProvider) As UInt64 Implements IConvertible.ToUInt64
 Return Convert.ToUInt64(GetDoubleValue())
 End Function
 End Class
 Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
 Dim testComplex As New Complex(4, 7)
 WriteObjectInfo(outputBlock, testComplex)
 WriteObjectInfo(outputBlock, Convert.ToBoolean(testComplex))
 WriteObjectInfo(outputBlock, Convert.ToDecimal(testComplex))
 WriteObjectInfo(outputBlock, Convert.ToString(testComplex))
 End Sub
 Sub WriteObjectInfo(ByVal outputBlock As System.Windows.Controls.TextBlock, ByVal testObject As Object)
 Dim typeCode As TypeCode = Type.GetTypeCode(testObject.GetType())
 Select Case typeCode
 Case typeCode.Boolean
 outputBlock.Text += String.Format("Boolean: {0}", testObject) & vbCrLf
 Case typeCode.Double
 outputBlock.Text += String.Format("Double: {0}", testObject) & vbCrLf
 Case Else
 outputBlock.Text += String.Format("{0}: {1}", typeCode.ToString(), testObject) & vbCrLf
 End Select
 End Sub
End Module

using System;
/// Class that implements IConvertible
class Complex : IConvertible
{
 double x;
 double y;
 public Complex(double x, double y)
 {
 this.x = x;
 this.y = y;
 }
 public TypeCode GetTypeCode()
 {
 return TypeCode.Object;
 }
 bool IConvertible.ToBoolean(IFormatProvider provider)
 {
 if ((x != 0.0) || (y != 0.0))
 return true;
 else
 return false;
 }
 double GetDoubleValue()
 {
 return Math.Sqrt(x * x + y * y);
 }
 byte IConvertible.ToByte(IFormatProvider provider)
 {
 return Convert.ToByte(GetDoubleValue());
 }
 char IConvertible.ToChar(IFormatProvider provider)
 {
 return Convert.ToChar(GetDoubleValue());
 }
 DateTime IConvertible.ToDateTime(IFormatProvider provider)
 {
 return Convert.ToDateTime(GetDoubleValue());
 }
 decimal IConvertible.ToDecimal(IFormatProvider provider)
 {
 return Convert.ToDecimal(GetDoubleValue());
 }
 double IConvertible.ToDouble(IFormatProvider provider)
 {
 return GetDoubleValue();
 }
 short IConvertible.ToInt16(IFormatProvider provider)
 {
 return Convert.ToInt16(GetDoubleValue());
 }
 int IConvertible.ToInt32(IFormatProvider provider)
 {
 return Convert.ToInt32(GetDoubleValue());
 }
 long IConvertible.ToInt64(IFormatProvider provider)
 {
 return Convert.ToInt64(GetDoubleValue());
 }
 sbyte IConvertible.ToSByte(IFormatProvider provider)
 {
 return Convert.ToSByte(GetDoubleValue());
 }
 float IConvertible.ToSingle(IFormatProvider provider)
 {
 return Convert.ToSingle(GetDoubleValue());
 }
 string IConvertible.ToString(IFormatProvider provider)
 {
 return "( " + x.ToString() + " , " + y.ToString() + " )";
 }
 object IConvertible.ToType(Type conversionType, IFormatProvider provider)
 {
 return Convert.ChangeType(GetDoubleValue(), conversionType, provider);
 }
 ushort IConvertible.ToUInt16(IFormatProvider provider)
 {
 return Convert.ToUInt16(GetDoubleValue());
 }
 uint IConvertible.ToUInt32(IFormatProvider provider)
 {
 return Convert.ToUInt32(GetDoubleValue());
 }
 ulong IConvertible.ToUInt64(IFormatProvider provider)
 {
 return Convert.ToUInt64(GetDoubleValue());
 }
}
/// <summary>
/// Summary description for Class1.
/// </summary>
class Example
{
 public static void Demo(System.Windows.Controls.TextBlock outputBlock)
 {
 Complex testComplex = new Complex(4, 7);
 WriteObjectInfo(outputBlock, testComplex);
 WriteObjectInfo(outputBlock, Convert.ToBoolean(testComplex));
 WriteObjectInfo(outputBlock, Convert.ToDecimal(testComplex));
 WriteObjectInfo(outputBlock, Convert.ToString(testComplex));
 }
 static void WriteObjectInfo(System.Windows.Controls.TextBlock outputBlock, object testObject)
 {
 TypeCode typeCode = Type.GetTypeCode(testObject.GetType());
 switch (typeCode)
 {
 case TypeCode.Boolean:
 outputBlock.Text += String.Format("Boolean: {0}", testObject) + "\n";
 break;
 case TypeCode.Double:
 outputBlock.Text += String.Format("Double: {0}", testObject) + "\n";
 break;
 default:
 outputBlock.Text += String.Format("{0}: {1}", typeCode.ToString(), testObject) + "\n";
 break;
 }
 }
}

System Namespace