string stringValue = "1.35";
decimal d = System.Convert.ToDecimal( stringValue );
次のような変換メソッドがあります
ChangeType
FromBase64CharArray
FromBase64String
FromHexString
GetTypeCode
IsDBNull
ToBase64CharArray
ToBase64String
ToBoolean
ToByte
ToChar
ToDateTime
ToDecimal
ToDouble
ToHexString
ToInt16
ToInt32
ToInt64
ToSByte
ToSingle
ToString
ToUInt16
ToUInt32
ToUInt64
TryFromBase64Chars
TryFromBase64String
TryToBase64Chars