Udostępnij za pośrednictwem

  • Artykuł

Convert.ToChar Method (String)

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Converts the first character of a String to a Unicode character.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

Syntax

'Declaration
Public Shared Function ToChar ( _
    value As String _
) As Char

public static char ToChar(
    string value
)

Parameters

  • value
    Type: System.String
    A String of length 1 or nulla null reference (Nothing in Visual Basic).

Return Value

Type: System.Char
The Unicode character equivalent to the first and only character in value.

Exceptions

Exception Condition
ArgumentNullException

value is nulla null reference (Nothing in Visual Basic).
FormatException

The length of value is not 1.

Remarks

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.

Examples

The following code sample illustrates the use of ToByte, by attempting to convert a String value to a Char :

Public Sub ConvertStringChar(ByVal stringVal As String)
   Dim charVal As Char = "a"c

   ' A string must be one character long to convert to char.
   Try
      charVal = System.Convert.ToChar(stringVal)
      outputBlock.Text &= String.Format("{0} as a char is {1}", _
                                stringVal, charVal) & vbCrLf
   Catch exception As System.FormatException
      outputBlock.Text &= String.Format( _
       "The string is longer than one character.") & vbCrLf
   Catch exception As System.ArgumentNullException
      outputBlock.Text &= "The string is null." & vbCrLf
   End Try

   ' A char to string conversion will always succeed.
   stringVal = System.Convert.ToString(charVal)
   outputBlock.Text &= String.Format("The character as a string is {0}", _
                             stringVal) & vbCrLf
End Sub

public void ConvertStringChar(string stringVal)
{
   char charVal = 'a';

   // A string must be one character long to convert to char.
   try
   {
      charVal = System.Convert.ToChar(stringVal);
      outputBlock.Text += String.Format("{0} as a char is {1}",
         stringVal, charVal) + "\n";
   }
   catch (System.FormatException)
   {
      outputBlock.Text += String.Format(
         "The string is longer than one character.") + "\n";
   }
   catch (System.ArgumentNullException)
   {
      outputBlock.Text += "The string is null." + "\n";
   }

   // A char to string conversion will always succeed.
   stringVal = System.Convert.ToString(charVal);
   outputBlock.Text += String.Format("The character as a string is {0}",
         stringVal) + "\n";
}

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.