System.Data.SqlClient.SqlParameter.ValidateTypeLengths C# (CSharp) Méthode

        internal MetaType ValidateTypeLengths()
        {
            MetaType mt = InternalMetaType;
            // Since the server will automatically reject any
            // char, varchar, binary, varbinary, nchar, or nvarchar parameter that has a
            // byte sizeInCharacters > 8000 bytes, we promote the parameter to image, text, or ntext.  This
            // allows the user to specify a parameter type using a COM+ datatype and be able to
            // use that parameter against a BLOB column.
            if ((SqlDbType.Udt != mt.SqlDbType) && (false == mt.IsFixed) && (false == mt.IsLong))
            { // if type has 2 byte length
                long actualSizeInBytes = this.GetActualSize();
                long sizeInCharacters = this.Size;

                // 'actualSizeInBytes' is the size of value passed; 
                // 'sizeInCharacters' is the parameter size;
                // 'actualSizeInBytes' is in bytes; 
                // 'this.Size' is in characters; 
                // 'sizeInCharacters' is in characters; 
                // 'TdsEnums.TYPE_SIZE_LIMIT' is in bytes;
                // For Non-NCharType and for non-Yukon or greater variables, size should be maintained;
                // Modified variable names from 'size' to 'sizeInCharacters', 'actualSize' to 'actualSizeInBytes', and 
                // 'maxSize' to 'maxSizeInBytes'
                // The idea is to
                // Keeping these goals in mind - the following are the changes we are making

                long maxSizeInBytes = 0;
                if (mt.IsNCharType)
                    maxSizeInBytes = ((sizeInCharacters * sizeof(char)) > actualSizeInBytes) ? sizeInCharacters * sizeof(char) : actualSizeInBytes;
                else
                {
                    // Notes:
                    // Elevation from (n)(var)char (4001+) to (n)text succeeds without failure only with Yukon and greater.
                    // it fails in sql server 2000
                    maxSizeInBytes = (sizeInCharacters > actualSizeInBytes) ? sizeInCharacters : actualSizeInBytes;
                }

                if ((maxSizeInBytes > TdsEnums.TYPE_SIZE_LIMIT) || (_coercedValueIsDataFeed) ||
                    (sizeInCharacters == -1) || (actualSizeInBytes == -1))
                { // is size > size able to be described by 2 bytes
                    // Convert the parameter to its max type
                    mt = MetaType.GetMaxMetaTypeFromMetaType(mt);
                    _metaType = mt;
                    InternalMetaType = mt;
                    if (!mt.IsPlp)
                    {
                        if (mt.SqlDbType == SqlDbType.Xml)
                        {
                            throw ADP.InvalidMetaDataValue();     //Xml should always have IsPartialLength = true
                        }
                        if (mt.SqlDbType == SqlDbType.NVarChar
                         || mt.SqlDbType == SqlDbType.VarChar
                         || mt.SqlDbType == SqlDbType.VarBinary)
                        {
                            Size = (int)(SmiMetaData.UnlimitedMaxLengthIndicator);
                        }
                    }
                }
            }
            return mt;
        }