System Namespace Convert Class
Converts the value of a subset of an 8-bit unsigned integer array to an equivalent subset of a Unicode character array consisting of base 64 digits. Parameters specify the subsets as offsets of the input and output arrays and the number of elements in the input array.
[ VB ]
Public Shared Function ToBase64CharArray ( _
ByVal inArray( ) As Byte, _
ByVal offsetIn As Integer, _
ByVal length As Integer, _
ByVal outArray( ) As Char, _
ByVal offsetOut As Integer _
) As Integer
[ C# ]
public static int ToBase64CharArray (
byte[ ] inArray,
int offsetIn,
int length,
char[ ] outArray,
int offsetOut
);
[ C++ ]
public: static int ToBase64CharArray (
unsigned char inArray __gc [ ],
int offsetIn,
int length,
__wchar_t outArray __gc [ ],
int offsetOut
);
[ JScript ]
public static function ToBase64CharArray (
inArray : Byte[ ],
offsetIn : int,
length : int,
outArray : Char[ ],
offsetOut : int
) : int;
- inArray
- An input array of 8-bit unsigned integers.
- offsetIn
- A position within inArray.
- length
- The number of elements of inArray to convert.
- outArray
- An output array of Unicode characters.
- offsetOut
- A position within outArray.
A 32-bit signed integer containing the number of bytes in outArray.
| Exception Type |
Condition |
| ArgumentNullException |
inArray is a null reference ( Nothing in Visual Basic ). |
| ArgumentOutOfRangeException |
offsetIn, offsetOut, or length is negative.
-or-
offsetIn plus length is greater than the length of inArray.
-or-
offsetOut plus the number of elements to return is greater than the length of outArray.
|
The subset of length elements of inArray starting at position offsetIn, are taken as a numeric value and converted to a subset of elements in outArray starting at position offsetOut. The return value indicates the number of converted elements in outArray. The subset of outArray consists of base 64 digits.
The base 64 digits in ascending order from zero are the uppercase characters 'A' to 'Z', lowercase characters 'a' to 'z', numerals '0' to '9', and the symbols '+' and '/'. The valueless character, '=', is used for trailing padding.
offset and length are 32-bit signed numbers. offsetIn and offsetOut are zero-based array positions.
The following sample demonstrates the ToBase64CharArray method.
[ VB ]
Public Sub EncodeWithCharArray ( )
Dim inFile As System.IO.FileStream
Dim binaryData ( ) As Byte
Try
inFile = New System.IO.FileStream ( inputFileName, _
System.IO.FileMode.Open, _
System.IO.FileAccess.Read )
ReDim binaryData ( inFile.Length )
Dim bytesRead As Long = inFile.Read ( binaryData, _
0, _
CInt ( inFile.Length ) )
inFile.Close ( )
Catch exp As System.Exception
' Error creating stream or reading from it.
System.Response.WriteLine ( "{0}", exp.Message )
Return
End Try
' Convert the binary input into Base64 UUEncoded output.
' Each 3 byte sequence in the source data becomes a 4 byte
' sequence in the character array.
Dim arrayLength As Long
arrayLength = ( 4 / 3 ) * binaryData.Length
If arrayLength Mod 4 <> 0 Then
arrayLength = arrayLength + 4 - arrayLength Mod 4
End If
Dim base64CharArray ( arrayLength - 1 ) As Char
Try
System.Convert.ToBase64CharArray ( binaryData, _
0, _
binaryData.Length, _
base64CharArray, 0 )
Catch exp As System.ArgumentNullException
System.Response.WriteLine ( "Binary data array is null." )
Return
Catch exp As System.ArgumentOutOfRangeException
System.Response.WriteLine ( "Char Array is not large enough." )
Return
End Try
' Write the UUEncoded version to the output file.
Dim outFile As System.IO.StreamWriter
Try
outFile = New System.IO.StreamWriter ( outputFileName, _
False, _
System.Text.Encoding.ASCII )
outFile.Write ( base64CharArray )
outFile.Close ( )
Catch exp As System.Exception
' Error creating stream or writing to it.
System.Response.WriteLine ( "{0}", exp.Message )
End Try
End Sub
[ C# ]
public void EncodeWithCharArray ( ) {
System.IO.FileStream inFile;
byte [ ] binaryData;
try {
inFile = new System.IO.FileStream ( inputFileName,
System.IO.FileMode.Open,
System.IO.FileAccess.Read );
binaryData = new Byte [ inFile.Length ];
long bytesRead = inFile.Read ( binaryData, 0,
( int ) inFile.Length );
inFile.Close ( );
}
catch ( System.Exception exp ) {
// Error creating stream or reading from it.
System.Response.WriteLine ( "{0}", exp.Message );
return;
}
// Convert the binary input into Base64 UUEncoded output.
// Each 3 byte sequence in the source data becomes a 4 byte
// sequence in the character array.
long arrayLength = ( long ) ( ( 4.0d/3.0d ) * binaryData.Length );
// If array length is not divisible by 4, go up to the next
// multiple of 4.
if ( arrayLength % 4 != 0 ) {
arrayLength += 4 - arrayLength % 4;
}
char [ ] base64CharArray = new char [ arrayLength ];
try {
System.Convert.ToBase64CharArray ( binaryData,
0,
binaryData.Length,
base64CharArray,
0 );
}
catch ( System.ArgumentNullException ) {
System.Response.WriteLine ( "Binary data array is null." );
return;
}
catch ( System.ArgumentOutOfRangeException ) {
System.Response.WriteLine ( "Char Array is not large enough." );
return;
}
// Write the UUEncoded version to the output file.
System.IO.StreamWriter outFile;
try {
outFile = new System.IO.StreamWriter ( outputFileName,
false,
System.Text.Encoding.ASCII );
outFile.Write ( base64CharArray );
outFile.Close ( );
}
catch ( System.Exception exp ) {
// Error creating stream or writing to it.
System.Response.WriteLine ( "{0}", exp.Message );
}
}
Convert Members
