JeffreySu/WeiXinMPSDK · error · ArgumentOutOfRangeException

requestMethod

Error message

requestMethod

What it means

GetHttpMethod maps the ApiRequestMethod enum to System.Net.Http.HttpMethod; any value outside GET/POST/PUT/PATCH/DELETE falls into the default arm and throws ArgumentOutOfRangeException(nameof(requestMethod)). The message is just the parameter name.

Solutions

1. Use only defined ApiRequestMethod members: GET, POST, PUT, PATCH, DELETE.
2. Validate/parse inbound values with Enum.TryParse<ApiRequestMethod> before passing them on.
3. If you need a verb the library doesn't map, extend ApiRequestMethod and the switch, or use a lower-level HttpClient path.

Example fix

// before
var method = (ApiRequestMethod)99; // invalid
// after
if (!Enum.TryParse<ApiRequestMethod>(raw, out var method))
    method = ApiRequestMethod.GET;

if (!Enum.IsDefined(typeof(ApiRequestMethod), method))
    throw new ArgumentException($"Unsupported ApiRequestMethod: {method}");

bool IsValidMethod(ApiRequestMethod m) => m is ApiRequestMethod.GET or ApiRequestMethod.POST or ApiRequestMethod.PUT or ApiRequestMethod.PATCH or ApiRequestMethod.DELETE;

try { await client.SendAsync(method, url); }
catch (ArgumentOutOfRangeException ex) { logger.LogError(ex, "Unknown HTTP method enum value"); }

When it happens

Trigger: Passing an undefined/invalid ApiRequestMethod value (e.g. an int cast that doesn't correspond to a defined enum member) into SendAsync/request building, typically via GetHttpMethod.

Common situations: Enum deserialized from config or a database string that produced a non-member value; casting an int constant to ApiRequestMethod; a custom extension that introduced a new verb the switch doesn't handle.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

• certType
• ArgumentOutOfRangeException (certType: RSA/SM only)
• sendType
• requestMethod
• 超时时间必须大于 0，或使用 Timeout.Infinite。

AI-assisted analysis of JeffreySu/WeiXinMPSDK@be573f6f94 (2026-09-12). Data as JSON: /api/errors/835f9f71cdcc3865. Report an issue: GitHub.

Appendix: source

Thrown at src/Senparc.Weixin.TenPay/Senparc.Weixin.TenPayV3/TenPayHttpClient/TenPayHttpClient.cs:248

            request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("*/*"));

            var userAgentValues = UserAgentValues.Instance;
            request.Headers.UserAgent.Add(new ProductInfoHeaderValue("Senparc.Weixin.TenPayV3-C#", userAgentValues.TenPayV3Version));
            request.Headers.UserAgent.Add(new ProductInfoHeaderValue($"(Senparc.Weixin {userAgentValues.SenparcWeixinVersion})"));
            request.Headers.UserAgent.Add(new ProductInfoHeaderValue(".NET", userAgentValues.RuntimeVersion));
            request.Headers.UserAgent.Add(new ProductInfoHeaderValue($"({userAgentValues.OSVersion})"));
        }

        protected HttpMethod GetHttpMethod(ApiRequestMethod requestMethod)
        {
            return requestMethod switch
            {
                ApiRequestMethod.GET => HttpMethod.Get,
                ApiRequestMethod.POST => HttpMethod.Post,
                ApiRequestMethod.PUT => HttpMethod.Put,
                ApiRequestMethod.PATCH => HttpMethod.Patch,
                ApiRequestMethod.DELETE => HttpMethod.Delete,
                _ => throw new ArgumentOutOfRangeException(nameof(requestMethod)),
            };
        }

        protected async Task<string> GenerateAuthorizationHeader(HttpRequestMessage request)
        {
            string method = request.Method.ToString();
            string body = "";
            if (method == "POST" || method == "PUT" || method == "PATCH")
            {
                var content = request.Content;
                body = await content.ReadAsStringAsync();
            }

            string uri = request.RequestUri.PathAndQuery;
            var timestamp = DateTimeOffset.Now.ToUnixTimeSeconds();
            string nonce = Path.GetRandomFileName();

            string message = $"{method}\n{uri}\n{timestamp}\n{nonce}\n{body}\n";

View on GitHub (pinned to be573f6f94)