Convert::ToChar Method (String, IFormatProvider)
Converts the first character of a specified string to a Unicode character, using specified culture-specific formatting information.
Assembly: mscorlib (in mscorlib.dll)
Parameters
- value
- Type: System::String
A string of length 1 or nullptr.
- provider
- Type: System::IFormatProvider
An object that supplies culture-specific formatting information. This parameter is ignored.
Return Value
Type: System::CharA Unicode character that is equivalent to the first and only character in value.
| Exception | Condition |
|---|---|
| ArgumentNullException | value is nullptr. |
| FormatException | The length of value is not 1. |
value must be a string that contains a single character.
If you prefer not to handle an exception if the conversion fails, you can call the Char::TryParse method instead. It returns a Boolean value that indicates whether the conversion succeeded or failed.
The following example converts a string representation of a Char value with the ToChar method, using an IFormatProvider object that displays the type of the format provider for which it is called. The example shows that the format provider is not referenced.
using namespace System; using namespace System::Globalization; ref class DummyProvider: public IFormatProvider { public: // Normally, GetFormat returns an object of the requested type // (usually itself) if it is able; otherwise, it returns Nothing. virtual Object^ GetFormat( Type^ argType ) { // Here, GetFormat displays the name of argType, after removing // the namespace information. GetFormat always returns null. String^ argStr = argType->ToString(); if ( argStr->Equals( "" ) ) argStr = "Empty"; argStr = argStr->Substring( argStr->LastIndexOf( '.' ) + 1 ); Console::Write( "{0,-20}", argStr ); return (Object^)0; } }; int main() { // Create an instance of IFormatProvider. DummyProvider^ provider = gcnew DummyProvider; String^ format = "{0,-17}{1,-17}{2}"; // Convert these values using DummyProvider. String^ Int32A = "-252645135"; String^ DoubleA = "61680.3855"; String^ DayTimeA = "2001/9/11 13:45"; String^ BoolA = "True"; String^ StringA = "Qwerty"; String^ CharA = "$"; Console::WriteLine( "This example of selected " "Convert::To<Type>( String*, IFormatProvider* ) \nmethods " "generates the following output. The example displays the " "\nprovider type if the IFormatProvider is called." ); Console::WriteLine( "\nNote: For the " "ToBoolean, ToString, and ToChar methods, the \n" "IFormatProvider object is not referenced." ); // The format provider is called for the following conversions. Console::WriteLine(); Console::WriteLine( format, "ToInt32", Int32A, Convert::ToInt32( Int32A, provider ) ); Console::WriteLine( format, "ToDouble", DoubleA, Convert::ToDouble( DoubleA, provider ) ); Console::WriteLine( format, "ToDateTime", DayTimeA, Convert::ToDateTime( DayTimeA, provider ) ); // The format provider is not called for these conversions. Console::WriteLine(); Console::WriteLine( format, "ToBoolean", BoolA, Convert::ToBoolean( BoolA, provider ) ); Console::WriteLine( format, "ToString", StringA, Convert::ToString( StringA, provider ) ); Console::WriteLine( format, "ToChar", CharA, Convert::ToChar( CharA, provider ) ); } /* This example of selected Convert::To<Type>( String*, IFormatProvider* ) methods generates the following output. The example displays the provider type if the IFormatProvider is called. Note: For the ToBoolean, ToString, and ToChar methods, the IFormatProvider object is not referenced. NumberFormatInfo ToInt32 -252645135 -252645135 NumberFormatInfo ToDouble 61680.3855 61680.3855 DateTimeFormatInfo ToDateTime 2001/9/11 13:45 9/11/2001 1:45:00 PM ToBoolean True True ToString Qwerty Qwerty ToChar $ $ */
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.