Επεξεργασία

Κοινή χρήση μέσω

ASCIIEncoding.GetMaxCharCount(Int32) Method

  • Reference

Definition

Namespace:
System.Text
Assemblies:
mscorlib.dll, System.Text.Encoding.Extensions.dll
Assembly:
System.Text.Encoding.Extensions.dll
Assembly:
mscorlib.dll
Assembly:
netstandard.dll
Source:
ASCIIEncoding.cs
Source:
ASCIIEncoding.cs
Source:
ASCIIEncoding.cs

Calculates the maximum number of characters produced by decoding the specified number of bytes.

public:
 override int GetMaxCharCount(int byteCount);
public override int GetMaxCharCount (int byteCount);
override this.GetMaxCharCount : int -> int
Public Overrides Function GetMaxCharCount (byteCount As Integer) As Integer

Parameters

byteCount
Int32

The number of bytes to decode.

Returns

Int32

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

Exceptions

ArgumentOutOfRangeException

byteCount is less than zero.

-or-

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

Examples

The following example demonstrates how to use the GetMaxCharCount method to calculate the maximum number of characters needed to decode a specified number of bytes.

using namespace System;
using namespace System::Text;
int main()
{
   ASCIIEncoding^ ascii = gcnew ASCIIEncoding;
   int byteCount = 8;
   int maxCharCount = ascii->GetMaxCharCount( byteCount );
   Console::WriteLine( "Maximum of {0} characters needed to decode {1} bytes.", maxCharCount, byteCount );
}

using System;
using System.Text;

class ASCIIEncodingExample {
    public static void Main() {
        ASCIIEncoding ascii = new ASCIIEncoding();
        int byteCount = 8;
        int maxCharCount = ascii.GetMaxCharCount(byteCount);
        Console.WriteLine(
            "Maximum of {0} characters needed to decode {1} bytes.",
            maxCharCount,
            byteCount
        );
    }
}

Imports System.Text

Class ASCIIEncodingExample
    Public Shared Sub Main()
        Dim ascii As New ASCIIEncoding()
        Dim byteCount As Integer = 8
        Dim maxCharCount As Integer = ascii.GetMaxCharCount(byteCount)
        Console.WriteLine( _
            "Maximum of {0} characters needed to decode {1} bytes.", _
            maxCharCount, _
            byteCount _
        )
    End Sub
End Class

Remarks

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

GetMaxCharCount retrieves a worst-case number, including the worst case for the currently selected DecoderFallback. If a decoder fallback is present that has a maximum fallback length of n, the GetMaxCharCount method returns n * byteCount.

GetMaxCharCount has no relation to GetBytes. If your application needs a similar function to use with GetBytes, it should use GetMaxByteCount.

Note

GetMaxCharCount(N) is not necessarily the same value as N* GetMaxCharCount(1).

Applies to

See also