jQuery Ajax POST请求WebAPI 2.1控制器失败：未找到匹配HTTP资源

当前错误是因为WebAPI无法将你发送的JSON请求体与控制器方法的三个独立字符串参数绑定——默认情况下，WebAPI会从URI查询字符串中获取简单类型参数，而你通过请求体发送JSON对象，导致找不到匹配的Action。

1. 修正控制器代码 #

方式一：使用ViewModel封装参数（推荐） #

创建与前端JSON结构匹配的ViewModel类，让WebAPI自动完成请求体绑定：

// 定义ViewModel
public class DiscrepancyReportViewModel
{
    public string lid { get; set; }
    public string ProblemTypes { get; set; }
    public string ProblemTypeOther { get; set; }
}

// 修正控制器方法
[Route("api/reportdiscrepancy")]
[HttpPost]
public async Task<IHttpActionResult> ReportDiscrepancy([FromBody] DiscrepancyReportViewModel model)
{
    string retval = string.Empty;
    if (model == null)
    {
        return BadRequest("无效的请求数据");
    }

    string lid = AppCore.Validation.StripToGUID(model.lid);
    string problemTypes = AppCore.Validation.StripToDigitInCSVFromStr(model.ProblemTypes);
    string problemTypeOther = AppCore.Validation.StripAllCharsForMetaTag(StripHtml(model.ProblemTypeOther));
    var session = HttpContext.Current.Session;

    if (lid.Length == 36 && (problemTypes.Length > 0 || problemTypeOther.Length > 0))
    {
        if (IsGUID(lid))
        {
            if (session != null && !string.IsNullOrEmpty(session.SessionID))
            {
                var dr = new Discrepancy
                {
                    lid = lid,
                    SessionId = session.SessionID,
                    IPAddress = Ops.Site.GetUserIP(HttpContext.Current),
                    UserId = "anonymous"
                };
                if (User?.Identity?.IsAuthenticated == true)
                {
                    dr.UserId = User.Identity.GetUserId();
                }
                dr.ProblemTypeIds = problemTypes;
                dr.ProblemTypeOther = problemTypeOther;
                dr.idx = await DiscrepancyReportData.InsertDiscrepancyAsync(dr);
                if (dr.idx > 0)
                {
                    retval = "success";
                }
            }
        }
    }

    return Ok(retval);
}

方式二：单个[FromBody]动态参数（不推荐，仅当不想创建ViewModel时） #

如果不想创建ViewModel，可通过动态参数接收请求体：

[Route("api/reportdiscrepancy")]
[HttpPost]
public async Task<IHttpActionResult> ReportDiscrepancy([FromBody] dynamic model)
{
    string lid = AppCore.Validation.StripToGUID(model.lid.ToString());
    string problemTypes = AppCore.Validation.StripToDigitInCSVFromStr(model.ProblemTypes.ToString());
    string problemTypeOther = AppCore.Validation.StripAllCharsForMetaTag(StripHtml(model.ProblemTypeOther.ToString()));
    // 后续逻辑同方式一
}

2. 修正jQuery代码（jQuery 3.x+） #

优化请求路径与代码逻辑，确保格式匹配：

$("#btnSendReport").on('click', function (e) {
    e.preventDefault(); // 阻止默认提交行为
    var parElem = $(this).closest('.report-container'); // 用closest替代多层parent，更可靠
    var listID = parElem.find("#hidLID").val();
    var problemTypes = parElem.find('option:selected').map(function () { 
        return this.value; 
    }).get().join(',');
    var problemTypeOther = parElem.find("#txtProblemTypeOther").val();

    var requestData = {
        lid: listID,
        ProblemTypes: problemTypes,
        ProblemTypeOther: problemTypeOther
    };

    $.ajax({
        type: "POST",
        url: "/api/reportdiscrepancy", // 使用根相对路径，避免层级错误
        data: JSON.stringify(requestData),
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        success: function (response) {
            console.log("提交成功:", response);
            // 可添加前端反馈逻辑，如提示用户、隐藏弹窗等
        },
        error: function (xhr, status, error) {
            console.error("提交失败:", status, error);
        }
    });
});

额外检查点 #

• 确认WebAPI配置启用JSON格式化：在WebApiConfig.cs中添加

config.Formatters.JsonFormatter.SupportedMediaTypes.Add(new MediaTypeHeaderValue("application/json"));

• 检查控制器类是否正确继承ApiController，无冲突路由属性
• 确保请求URL的域名、端口与WebAPI部署地址一致，若跨域需配置CORS

内容的提问来源于stack exchange，提问作者MC9000