UTF8Encoding.GetCharCount UTF8Encoding.GetCharCount UTF8Encoding.GetCharCount UTF8Encoding.GetCharCount Method

Definition

Calculates the number of characters produced by decoding a sequence of bytes.

Overloads

GetCharCount(Byte[], Int32, Int32) GetCharCount(Byte[], Int32, Int32) GetCharCount(Byte[], Int32, Int32) GetCharCount(Byte[], Int32, Int32)

Calculates the number of characters produced by decoding a sequence of bytes from the specified byte array.

GetCharCount(ReadOnlySpan<Byte>) GetCharCount(ReadOnlySpan<Byte>) GetCharCount(ReadOnlySpan<Byte>) GetCharCount(ReadOnlySpan<Byte>)

Calculates the number of characters produced by decoding the specified byte span.

GetCharCount(Byte*, Int32) GetCharCount(Byte*, Int32) GetCharCount(Byte*, Int32)

Calculates the number of characters produced by decoding a sequence of bytes starting at the specified byte pointer.

GetCharCount(Byte[], Int32, Int32) GetCharCount(Byte[], Int32, Int32) GetCharCount(Byte[], Int32, Int32) GetCharCount(Byte[], Int32, Int32)

Calculates the number of characters produced by decoding a sequence of bytes from the specified byte array.

public:
 override int GetCharCount(cli::array <System::Byte> ^ bytes, int index, int count);
public override int GetCharCount (byte[] bytes, int index, int count);
override this.GetCharCount : byte[] * int * int -> int
Public Overrides Function GetCharCount (bytes As Byte(), index As Integer, count As Integer) As Integer

Parameters

bytes
Byte[]

The byte array containing the sequence of bytes to decode.

index
Int32 Int32 Int32 Int32

The index of the first byte to decode.

count
Int32 Int32 Int32 Int32

The number of bytes to decode.

Returns

The number of characters produced by decoding the specified sequence of bytes.

Exceptions

index or count is less than zero.

-or-

index and count do not denote a valid range in bytes.

-or-

The resulting number of bytes is greater than the maximum number that can be returned as an integer.

Error detection is enabled, and bytes contains an invalid sequence of bytes.

Examples

The following example uses the GetCharCount method to return the number of characters produced by decoding a range of elements in a byte array.

using namespace System;
using namespace System::Text;
int main()
{
   array<Byte>^bytes = {85,84,70,56,32,69,110,99,111,100,105,110,103,32,69,120,97,109,112,108,101};
   UTF8Encoding^ utf8 = gcnew UTF8Encoding;
   int charCount = utf8->GetCharCount( bytes, 2, 8 );
   Console::WriteLine( "{0} characters needed to decode bytes.", charCount );
}

using System;
using System.Text;

class UTF8EncodingExample {
    public static void Main() {
        Byte[] bytes = new Byte[] {
             85,  84,  70,  56,  32,  69, 110,
             99, 111, 100, 105, 110, 103,  32,
             69, 120,  97, 109, 112, 108, 101
        };

        UTF8Encoding utf8 = new UTF8Encoding();
        int charCount = utf8.GetCharCount(bytes, 2, 8);
        Console.WriteLine(
            "{0} characters needed to decode bytes.", charCount
        );
    }
}
Imports System.Text

Class UTF8EncodingExample
    
    Public Shared Sub Main()
        Dim bytes() As Byte = { _
            85,  84,  70,  56,  32,  69, 110, _
            99, 111, 100, 105, 110, 103,  32, _
            69, 120,  97, 109, 112, 108, 101 _
        }
        
        Dim utf8 As New UTF8Encoding()
        Dim charCount As Integer = utf8.GetCharCount(bytes, 2, 8)
        Console.WriteLine("{0} characters needed to decode bytes.", charCount)
    End Sub
End Class

Remarks

To calculate the exact array size required by GetChars to store the resulting characters, call the GetCharCount method. To calculate the maximum array size, call the GetMaxCharCount method. The GetCharCount method generally allocates less memory, while the GetMaxCharCount method generally executes faster.

With error detection, an invalid sequence causes this method to throw an ArgumentException exception. Without error detection, invalid sequences are ignored, and no exception is thrown.

See also

GetCharCount(ReadOnlySpan<Byte>) GetCharCount(ReadOnlySpan<Byte>) GetCharCount(ReadOnlySpan<Byte>) GetCharCount(ReadOnlySpan<Byte>)

Calculates the number of characters produced by decoding the specified byte span.

public:
 override int GetCharCount(ReadOnlySpan<System::Byte> bytes);
public override int GetCharCount (ReadOnlySpan<byte> bytes);
override this.GetCharCount : ReadOnlySpan<byte> -> int
Public Overrides Function GetCharCount (bytes As ReadOnlySpan(Of Byte)) As Integer

Parameters

bytes
ReadOnlySpan<Byte>

The span containing the set of bytes to decode.

Returns

The number of characters produced by decoding the specified byte span.

Remarks

To calculate the exact size required by GetChars to store the resulting characters, call the GetCharCount method. To calculate the maximum size, call the GetMaxCharCount method. The GetCharCount method generally allocates less memory, while the GetMaxCharCount method generally executes faster.

With error detection, an invalid sequence causes this method to throw an ArgumentException exception. Without error detection, invalid sequences are ignored, and no exception is thrown.

GetCharCount(Byte*, Int32) GetCharCount(Byte*, Int32) GetCharCount(Byte*, Int32)

Important

This API is not CLS-compliant.

Calculates the number of characters produced by decoding a sequence of bytes starting at the specified byte pointer.

public:
 override int GetCharCount(System::Byte* bytes, int count);
[System.CLSCompliant(false)]
[System.Runtime.InteropServices.ComVisible(false)]
[System.Security.SecurityCritical]
public override int GetCharCount (byte* bytes, int count);
override this.GetCharCount : nativeptr<byte> * int -> int

Parameters

bytes
Byte*

A pointer to the first byte to decode.

count
Int32 Int32 Int32 Int32

The number of bytes to decode.

Returns

The number of characters produced by decoding the specified sequence of bytes.

Exceptions

count is less than zero.

-or-

The resulting number of bytes is greater than the maximum number that can be returned as an integer.

Error detection is enabled, and bytes contains an invalid sequence of bytes.

Remarks

To calculate the exact array size required by GetChars to store the resulting characters, call the GetCharCount method. To calculate the maximum array size, call the GetMaxCharCount method. The GetCharCount method generally allocates less memory, while the GetMaxCharCount method generally executes faster.

With error detection, an invalid sequence causes this method to throw an ArgumentException exception. Without error detection, invalid sequences are ignored, and no exception is thrown.

Security

SecurityCriticalAttribute
Requires full trust for the immediate caller. This member cannot be used by partially trusted or transparent code.

See also

Applies to