Convert.ToString Method (Object)
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Converts the value of the specified Object to its String representation.
Assembly: mscorlib (in mscorlib.dll)
Parameters
- value
- Type: System.Object
An Object or Nothing.
Return Value
Type: System.StringThe String representation of the value of value, or String.Empty if value is Nothing.
To convert value to its string representation, the method tries to call the IConvertible.ToString implementation of value. If value does not implement the IConvertible interface, the method tries to call the IFormattable.ToString implementation of value. If value does not implement the IFormattable interface, the method calls the ToString method of the underlying type of value.
The following code example converts a non-numeric Object and a boxed numeric value to String s with the ToString method, using default formatting.
' Example of Convert.ToString( non-numeric types, IFormatProvider ). Imports System.Globalization ' An instance of this class can be passed to methods that require ' an IFormatProvider. Public Class DummyProvider Implements IFormatProvider ' Normally, GetFormat returns an object of the requested type ' (usually itself) if it is able; otherwise, it returns Nothing. Public Function GetFormat(ByVal argType As Type) As Object _ Implements IFormatProvider.GetFormat ' Here, the type of argType is displayed, and GetFormat ' always returns Nothing. outputBlock.Text &= String.Format("{0,-40}", argType.ToString()) Return Nothing End Function End Class Module Example Public Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock) ' Create an instance of the IFormatProvider. Dim provider As New DummyProvider() Dim converted As String ' Convert these values using DummyProvider. Dim Int32A As Integer = -252645135 Dim DoubleA As Double = 61680.3855 Dim ObjDouble As Object = CType(-98765.4321, Object) Dim DayTimeA As DateTime = _ New DateTime(2001, 9, 11, 13, 45, 0) Dim BoolA As Boolean = True Dim StringA As String = "Qwerty" Dim CharA As Char = "$"c Dim TSpanA As TimeSpan = New TimeSpan(0, 18, 0) Dim ObjOther As Object = CType(provider, Object) outputBlock.Text &= "This example of " & _ "Convert.ToString( non-numeric, IFormatProvider ) " & _ vbCrLf & "generates the following output. The " & _ "provider type, argument type, " & vbCrLf & "and " & _ "argument value are displayed." & vbCrLf outputBlock.Text &= vbCrLf & _ "Note: The IFormatProvider object is not called for " & _ "Boolean, String, " & vbCrLf & "Char, TimeSpan, " & _ "and non-numeric Object." & vbCrLf ' The format provider is called for these conversions. outputBlock.Text &= vbCrLf converted = Convert.ToString(Int32A, provider) outputBlock.Text &= String.Format("Int32 {0}", converted) & vbCrLf converted = Convert.ToString(DoubleA, provider) outputBlock.Text &= String.Format("Double {0}", converted) & vbCrLf converted = Convert.ToString(ObjDouble, provider) outputBlock.Text &= String.Format("Object {0}", converted) & vbCrLf converted = Convert.ToString(DayTimeA, provider) outputBlock.Text &= String.Format("DateTime {0}", converted) & vbCrLf ' The format provider is not called for these conversions. outputBlock.Text &= vbCrLf converted = Convert.ToString(BoolA, provider) outputBlock.Text &= String.Format("Boolean {0}", converted) & vbCrLf converted = Convert.ToString(StringA, provider) outputBlock.Text &= String.Format("String {0}", converted) & vbCrLf converted = Convert.ToString(CharA, provider) outputBlock.Text &= String.Format("Char {0}", converted) & vbCrLf converted = Convert.ToString(TSpanA, provider) outputBlock.Text &= String.Format("TimeSpan {0}", converted) & vbCrLf converted = Convert.ToString(ObjOther, provider) outputBlock.Text &= String.Format("Object {0}", converted) & vbCrLf End Sub End Module ' This example of Convert.ToString( non-numeric, IFormatProvider ) ' generates the following output. The provider type, argument type, ' and argument value are displayed. ' ' Note: The IFormatProvider object is not called for Boolean, String, ' Char, TimeSpan, and non-numeric Object. ' ' System.Globalization.NumberFormatInfo Int32 -252645135 ' System.Globalization.NumberFormatInfo Double 61680.3855 ' System.Globalization.NumberFormatInfo Object -98765.4321 ' System.Globalization.DateTimeFormatInfo DateTime 9/11/2001 1:45:00 PM ' ' Boolean True ' String Qwerty ' Char $ ' TimeSpan 00:18:00 ' Object DummyProvider