Char.TryParse Method
Microsoft Silverlight will reach end of support after October 2021. Learn more.
Converts the value of the specified string to its equivalent Unicode character. A return code indicates whether the conversion succeeded or failed.
Namespace: System
Assembly: mscorlib (in mscorlib.dll)
Syntax
'Declaration
Public Shared Function TryParse ( _
s As String, _
<OutAttribute> ByRef result As Char _
) As Boolean
public static bool TryParse(
string s,
out char result
)
Parameters
- s
Type: System.String
A string containing a single character or nulla null reference (Nothing in Visual Basic).
- result
Type: System.Char%
When this method returns, contains a Unicode character equivalent to the sole character in s, if the conversion succeeded, or an undefined value if the conversion failed. The conversion fails if the s parameter is nulla null reference (Nothing in Visual Basic) or the length of s is not 1. This parameter is passed uninitialized.
Return Value
Type: System.Boolean
true if the s parameter was converted successfully; otherwise, false.
Remarks
The TryParse method does not throw an exception if the conversion fails.
Examples
The following example demonstrates overloads of the TryParse method for several base types, and the TryParseExact method for the DateTime base type.
' This example demonstrates overloads of the TryParse method for
' several base types, and the TryParseExact method for DateTime.
' In most cases, this example uses the most complex overload; that is, the overload
' with the most parameters for a particular type. If a complex overload specifies
' null (Nothing in Visual Basic) for the IFormatProvider parameter, formatting
' information is obtained from the culture associated with the current thread.
' If a complex overload specifies the style parameter, the parameter value is
' the default value used by the equivalent simple overload.
Imports System.Globalization
Class Example
Public Shared Sub Demo(ByVal outputBlock As System.Windows.Controls.TextBlock)
Dim result As Boolean
Dim ci As CultureInfo
Dim nl As String = vbCrLf
Dim msg1 As String = _
"This example demonstrates overloads of the TryParse method for{0}" & _
"several base types, as well as the TryParseExact method for DateTime.{0}"
Dim msg2 As String = "Non-numeric types:{0}"
Dim msg3 As String = "{0}Numeric types:{0}"
Dim msg4 As String = "{0}The following types are not CLS-compliant:{0}"
' Non-numeric types.
Dim booleanVal As [Boolean]
Dim charVal As [Char]
Dim datetimeVal As DateTime
' Numeric types.
Dim byteVal As [Byte]
Dim int16Val As Int16
Dim int32Val As Int32
Dim int64Val As Int64
Dim decimalVal As [Decimal]
Dim singleVal As [Single]
Dim doubleVal As [Double]
' The following types are not CLS-compliant.
Dim sbyteVal As SByte
Dim uint16Val As UInt16
Dim uint32Val As UInt32
Dim uint64Val As UInt64
'
outputBlock.Text &= String.Format(msg1, nl) & vbCrLf
' Non-numeric types:
outputBlock.Text &= String.Format(msg2, nl) & vbCrLf
' DateTime
' TryParse:
' Assume current culture is en-US, and dates of the form: MMDDYYYY.
result = DateTime.TryParse("7/4/2004 12:34:56", datetimeVal)
Show(outputBlock, result, "DateTime #1", datetimeVal.ToString())
' Use fr-FR culture, and dates of the form: DDMMYYYY.
ci = New CultureInfo("fr-FR")
result = DateTime.TryParse("4/7/2004 12:34:56", ci, DateTimeStyles.None, datetimeVal)
Show(outputBlock, result, "DateTime #2", datetimeVal.ToString())
' TryParseExact:
' Use fr-FR culture. The format, "G", is short date and long time.
result = DateTime.TryParseExact("04/07/2004 12:34:56", "G", ci, DateTimeStyles.None, datetimeVal)
Show(outputBlock, result, "DateTime #3", datetimeVal.ToString())
' Assume en-US culture.
Dim dateFormats As String() = {"f", "F", "g", "G"}
result = DateTime.TryParseExact("7/4/2004 12:34:56 PM", dateFormats, Nothing, DateTimeStyles.None, datetimeVal)
Show(outputBlock, result, "DateTime #4", datetimeVal.ToString())
outputBlock.Text &= vbCrLf
' Boolean
result = [Boolean].TryParse("true", booleanVal)
Show(outputBlock, result, "Boolean", booleanVal.ToString())
' Char
result = [Char].TryParse("A", charVal)
Show(outputBlock, result, "Char", charVal.ToString())
' Numeric types:
outputBlock.Text &= String.Format(msg3, nl) & vbCrLf
' Byte
result = [Byte].TryParse("1", NumberStyles.Integer, Nothing, byteVal)
Show(outputBlock, result, "Byte", byteVal.ToString())
' Int16
result = Int16.TryParse("-2", NumberStyles.Integer, Nothing, int16Val)
Show(outputBlock, result, "Int16", int16Val.ToString())
' Int32
result = Int32.TryParse("3", NumberStyles.Integer, Nothing, int32Val)
Show(outputBlock, result, "Int32", int32Val.ToString())
' Int64
result = Int64.TryParse("4", NumberStyles.Integer, Nothing, int64Val)
Show(outputBlock, result, "Int64", int64Val.ToString())
' Decimal
result = [Decimal].TryParse("-5.5", NumberStyles.Number, Nothing, decimalVal)
Show(outputBlock, result, "Decimal", decimalVal.ToString())
' Single
result = [Single].TryParse("6.6", NumberStyles.Float Or NumberStyles.AllowThousands, Nothing, singleVal)
Show(outputBlock, result, "Single", singleVal.ToString())
' Double
result = [Double].TryParse("-7", NumberStyles.Float Or NumberStyles.AllowThousands, Nothing, doubleVal)
Show(outputBlock, result, "Double", doubleVal.ToString())
' Use the simple Double.TryParse overload, but specify an invalid value.
result = [Double].TryParse("abc", doubleVal)
Show(outputBlock, result, "Double #2", doubleVal.ToString())
'
outputBlock.Text &= String.Format(msg4, nl) & vbCrLf
' SByte
result = SByte.TryParse("-8", NumberStyles.Integer, Nothing, sbyteVal)
Show(outputBlock, result, "SByte", sbyteVal.ToString())
' UInt16
result = UInt16.TryParse("9", NumberStyles.Integer, Nothing, uint16Val)
Show(outputBlock, result, "UInt16", uint16Val.ToString())
' UInt32
result = UInt32.TryParse("10", NumberStyles.Integer, Nothing, uint32Val)
Show(outputBlock, result, "UInt32", uint32Val.ToString())
' UInt64
result = UInt64.TryParse("11", NumberStyles.Integer, Nothing, uint64Val)
Show(outputBlock, result, "UInt64", uint64Val.ToString())
End Sub 'Main
Protected Shared Sub Show(ByVal outputBlock As System.Windows.Controls.TextBlock, ByVal parseResult As Boolean, ByVal typeName As String, ByVal parseValue As String)
Dim msgSuccess As String = "Parse for {0} = {1}"
Dim msgFailure As String = "** Parse for {0} failed. Invalid input."
'
If parseResult = True Then
outputBlock.Text &= String.Format(msgSuccess, typeName, parseValue) & vbCrLf
Else
outputBlock.Text &= String.Format(msgFailure, typeName) & vbCrLf
End If
End Sub 'Show
End Class 'Sample '
'This example produces the following results:
'
'This example demonstrates overloads of the TryParse method for
'several base types, as well as the TryParseExact method for DateTime.
'
'Non-numeric types:
'
'Parse for DateTime #1 = 7/4/2004 12:34:56 PM
'Parse for DateTime #2 = 7/4/2004 12:34:56 PM
'Parse for DateTime #3 = 7/4/2004 12:34:56 PM
'Parse for DateTime #4 = 7/4/2004 12:34:56 PM
'
'Parse for Boolean = True
'Parse for Char = A
'
'Numeric types:
'
'Parse for Byte = 1
'Parse for Int16 = -2
'Parse for Int32 = 3
'Parse for Int64 = 4
'Parse for Decimal = -5.5
'Parse for Single = 6.6
'Parse for Double = -7
'** Parse for Double #2 failed. Invalid input.
'
'The following types are not CLS-compliant:
'
'Parse for SByte = -8
'Parse for UInt16 = 9
'Parse for UInt32 = 10
'Parse for UInt64 = 11
'
// This example demonstrates overloads of the TryParse method for
// several base types, and the TryParseExact method for DateTime.
// In most cases, this example uses the most complex overload; that is, the overload
// with the most parameters for a particular type. If a complex overload specifies
// null (Nothing in Visual Basic) for the IFormatProvider parameter, formatting
// information is obtained from the culture associated with the current thread.
// If a complex overload specifies the style parameter, the parameter value is
// the default value used by the equivalent simple overload.
using System;
using System.Globalization;
class Example
{
public static void Demo(System.Windows.Controls.TextBlock outputBlock)
{
bool result;
CultureInfo ci;
string nl = "\n";
string msg1 =
"This example demonstrates overloads of the TryParse method for{0}" +
"several base types, as well as the TryParseExact method for DateTime.{0}";
string msg2 = "Non-numeric types:{0}";
string msg3 = "{0}Numeric types:{0}";
string msg4 = "{0}The following types are not CLS-compliant:{0}";
// Non-numeric types.
Boolean booleanVal;
Char charVal;
DateTime datetimeVal;
// Numeric types.
Byte byteVal;
Int16 int16Val;
Int32 int32Val;
Int64 int64Val;
Decimal decimalVal;
Single singleVal;
Double doubleVal;
// The following types are not CLS-compliant.
SByte sbyteVal;
UInt16 uint16Val;
UInt32 uint32Val;
UInt64 uint64Val;
//
outputBlock.Text += String.Format(msg1, nl) + "\n";
// Non-numeric types:
outputBlock.Text += String.Format(msg2, nl) + "\n";
// DateTime
// TryParse:
// Assume current culture is en-US, and dates of the form: MMDDYYYY.
result = DateTime.TryParse("7/4/2004 12:34:56", out datetimeVal);
Show(outputBlock, result, "DateTime #1", datetimeVal.ToString());
// Use fr-FR culture, and dates of the form: DDMMYYYY.
ci = new CultureInfo("fr-FR");
result = DateTime.TryParse("4/7/2004 12:34:56",
ci, DateTimeStyles.None, out datetimeVal);
Show(outputBlock, result, "DateTime #2", datetimeVal.ToString());
// TryParseExact:
// Use fr-FR culture. The format, "G", is short date and long time.
result = DateTime.TryParseExact("04/07/2004 12:34:56", "G",
ci, DateTimeStyles.None, out datetimeVal);
Show(outputBlock, result, "DateTime #3", datetimeVal.ToString());
// Assume en-US culture.
string[] dateFormats = { "f", "F", "g", "G" };
result = DateTime.TryParseExact("7/4/2004 12:34:56 PM",
dateFormats, null, DateTimeStyles.None,
out datetimeVal);
Show(outputBlock, result, "DateTime #4", datetimeVal.ToString());
outputBlock.Text += "\n";
// Boolean
result = Boolean.TryParse("true", out booleanVal);
Show(outputBlock, result, "Boolean", booleanVal.ToString());
// Char
result = Char.TryParse("A", out charVal);
Show(outputBlock, result, "Char", charVal.ToString());
// Numeric types:
outputBlock.Text += String.Format(msg3, nl) + "\n";
// Byte
result = Byte.TryParse("1", NumberStyles.Integer, null, out byteVal);
Show(outputBlock, result, "Byte", byteVal.ToString());
// Int16
result = Int16.TryParse("-2", NumberStyles.Integer, null, out int16Val);
Show(outputBlock, result, "Int16", int16Val.ToString());
// Int32
result = Int32.TryParse("3", NumberStyles.Integer, null, out int32Val);
Show(outputBlock, result, "Int32", int32Val.ToString());
// Int64
result = Int64.TryParse("4", NumberStyles.Integer, null, out int64Val);
Show(outputBlock, result, "Int64", int64Val.ToString());
// Decimal
result = Decimal.TryParse("-5.5", NumberStyles.Number, null, out decimalVal);
Show(outputBlock, result, "Decimal", decimalVal.ToString());
// Single
result = Single.TryParse("6.6",
(NumberStyles.Float | NumberStyles.AllowThousands),
null, out singleVal);
Show(outputBlock, result, "Single", singleVal.ToString());
// Double
result = Double.TryParse("-7",
(NumberStyles.Float | NumberStyles.AllowThousands),
null, out doubleVal);
Show(outputBlock, result, "Double", doubleVal.ToString());
// Use the simple Double.TryParse overload, but specify an invalid value.
result = Double.TryParse("abc", out doubleVal);
Show(outputBlock, result, "Double #2", doubleVal.ToString());
//
outputBlock.Text += String.Format(msg4, nl) + "\n";
// SByte
result = SByte.TryParse("-8", NumberStyles.Integer, null, out sbyteVal);
Show(outputBlock, result, "SByte", sbyteVal.ToString());
// UInt16
result = UInt16.TryParse("9", NumberStyles.Integer, null, out uint16Val);
Show(outputBlock, result, "UInt16", uint16Val.ToString());
// UInt32
result = UInt32.TryParse("10", NumberStyles.Integer, null, out uint32Val);
Show(outputBlock, result, "UInt32", uint32Val.ToString());
// UInt64
result = UInt64.TryParse("11", NumberStyles.Integer, null, out uint64Val);
Show(outputBlock, result, "UInt64", uint64Val.ToString());
}
protected static void Show(System.Windows.Controls.TextBlock outputBlock, bool parseResult, string typeName,
string parseValue)
{
string msgSuccess = "Parse for {0} = {1}";
string msgFailure = "** Parse for {0} failed. Invalid input.";
//
if (parseResult == true)
outputBlock.Text += String.Format(msgSuccess, typeName, parseValue) + "\n";
else
outputBlock.Text += String.Format(msgFailure, typeName) + "\n";
}
}
/*
This example produces the following results:
This example demonstrates overloads of the TryParse method for
several base types, as well as the TryParseExact method for DateTime.
Non-numeric types:
Parse for DateTime #1 = 7/4/2004 12:34:56 PM
Parse for DateTime #2 = 7/4/2004 12:34:56 PM
Parse for DateTime #3 = 7/4/2004 12:34:56 PM
Parse for DateTime #4 = 7/4/2004 12:34:56 PM
Parse for Boolean = True
Parse for Char = A
Numeric types:
Parse for Byte = 1
Parse for Int16 = -2
Parse for Int32 = 3
Parse for Int64 = 4
Parse for Decimal = -5.5
Parse for Single = 6.6
Parse for Double = -7
** Parse for Double #2 failed. Invalid input.
The following types are not CLS-compliant:
Parse for SByte = -8
Parse for UInt16 = 9
Parse for UInt32 = 10
Parse for UInt64 = 11
*/
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.