JeffreySu/WeiXinMPSDK · error · ArgumentException

参数不能为空。

Error message

参数不能为空。

What it means

EnsureNotEmpty is a private guard used by DecryptAndParse, ParsePlaintext and EncryptResponse in OpenHardwareCallbackHandler. It throws ArgumentException with the message 参数不能为空。 when a required string parameter (e.g. token, encodingAesKey, receiveId, timestamp, nonce, or the plaintext being parsed) is null, empty, or whitespace.

Solutions

  1. Supply all required string arguments (token, encodingAesKey, receiveId, timestamp, nonce, plaintext) with non-empty values
  2. Load configuration before the call and fail fast if token/aesKey/receiveId are missing
  3. Ensure the decrypt step succeeded and produced non-empty plaintext before calling ParsePlaintext

Example fix

// before
var msg = OpenHardwareCallbackHandler.ParsePlaintext<MyMsg>(decryptResult); // decryptResult == ""
// after
if (string.IsNullOrWhiteSpace(decryptResult)) throw new InvalidOperationException("Decrypt produced empty plaintext");
var msg = OpenHardwareCallbackHandler.ParsePlaintext<MyMsg>(decryptResult);
Defensive patterns

Strategy: validation

Validate before calling

string[] required = { token, encodingAesKey, receiveId, timestamp, nonce };
if (required.Any(string.IsNullOrWhiteSpace)) throw new InvalidOperationException("token/aesKey/receiveId/timestamp/nonce must all be non-empty");

Try / catch

try { var msg = OpenHardwareCallbackHandler.ParsePlaintext<TMessage>(plaintext); }
catch (ArgumentException ex) { logger.LogError(ex, "Empty parameter {Param}", ex.ParamName); return BadRequest(); }

Prevention

When it happens

Trigger: Calling DecryptAndParse / ParsePlaintext / EncryptResponse with any required string argument left null or empty — most often an unconfigured token or EncodingAESKey, or an empty callback payload/plaintext passed to ParsePlaintext.

Common situations: Configuration values read from appsettings/environment not yet set (empty strings); decrypt step returning empty string due to an earlier failed decrypt; passing null timestamp/nonce when synthesizing test requests.

Understand the failure class

Background: "must not be empty", "cannot be empty" — required-field validation errors across open-source libraries — this error's family across 41 libraries.

Related errors

AI-assisted analysis of JeffreySu/WeiXinMPSDK@be573f6f94 (2026-09-12). Data as JSON: /api/errors/a778c981ba152b5b. Report an issue: GitHub.

Appendix: source

Thrown at src/Senparc.Weixin.Work/Senparc.Weixin.Work/AdvancedAPIs/OpenHardware/OpenHardwareCallbackHandler.cs:223

            return new OpenHardwareEncryptedCallbackReply
            {
                encrypt = encryptedReply.encrypt,
                msgsignature = encryptedReply.msgsignature,
                timestamp = timestamp,
                nonce = encryptedReply.nonce
            };
        }

        private static TMessage Deserialize<TMessage>(string plaintext)
            where TMessage : OpenHardwareCallbackMessageBase
            => JsonConvert.DeserializeObject<TMessage>(plaintext);

        private static void EnsureNotEmpty(string value, string parameterName)
        {
            if (string.IsNullOrWhiteSpace(value))
            {
                throw new ArgumentException("参数不能为空。", parameterName);
            }
        }
    }
}

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