Azure Function无法获取请求体问题求助

问题描述 #

我创建了一个示例.NET 8 Function App并部署至Azure，通过POST请求发送数据调用函数时，函数能正常触发，但请求体始终返回为空/Null。以下是我的函数代码及local.settings.json配置：

函数代码 #

public static class Function1
{
    [FunctionName("Test")]
    public static async Task<IActionResult> Run(
        [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req,
        ILogger log)
    {
        string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
        log.LogInformation($" RequestBody: {requestBody}");

        string name = req.Query["name"];

        dynamic data = JsonConvert.DeserializeObject(requestBody);
        name = name ?? data?.name;

        string responseMessage = string.IsNullOrEmpty(name)
            ? "This HTTP triggered function executed successfully. Pass a name in the query string or in the request body for a personalized response."
            : $"Hello, {name}. This HTTP triggered function executed successfully.";

        return new OkObjectResult(responseMessage);
    }
}

local.settings.json配置 #

{
    "IsEncrypted": false,
    "Values": {
        "AzureWebJobsStorage": "UseDevelopmentStorage=true",
        "FUNCTIONS_INPROC_NET8_ENABLED": "1",
        "FUNCTIONS_WORKER_RUNTIME": "dotnet"
    }
}

解决方案 #

• 确保请求携带正确的Content-Type头
  POST请求必须设置Content-Type: application/json，否则Azure Functions无法正确识别JSON格式的请求体，导致req.Body读取为空。

• 改用模型绑定简化请求体处理
  .NET 8支持直接将请求体绑定到强类型模型，避免手动操作流的潜在问题。修改后的代码示例：

  public class NameRequest
  {
      public string Name { get; set; }
  }
  
  public static class Function1
  {
      [FunctionName("Test")]
      public static IActionResult Run(
          [HttpTrigger(AuthorizationLevel.Anonymous, "get", "post", Route = null)] HttpRequest req,
          [FromBody] NameRequest requestModel,
          ILogger log)
      {
          string name = req.Query["name"] ?? requestModel?.Name;
  
          string responseMessage = string.IsNullOrEmpty(name)
              ? "This HTTP triggered function executed successfully. Pass a name in the query string or in the request body for a personalized response."
              : $"Hello, {name}. This HTTP triggered function executed successfully.";
  
          return new OkObjectResult(responseMessage);
      }
  }
  

• 重置流位置后再读取
  如果坚持手动读取流，需确保流的指针回到起始位置，避免因流已被读取过导致空值：

  req.Body.Position = 0; // 添加这行重置流位置
  string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
  

• 检查请求体格式是否匹配
  如果使用Postman等工具测试，确认请求体是raw格式的JSON内容，而非form-data或x-www-form-urlencoded。如果是表单格式，需要通过req.Form["name"]获取参数，而非读取req.Body。

• 确认部署后的应用配置一致
  检查Azure门户中Function App的应用设置，确保FUNCTIONS_WORKER_RUNTIME为dotnet、FUNCTIONS_INPROC_NET8_ENABLED为1，与本地配置一致。

内容的提问来源于stack exchange，提问作者Balanjaneyulu K