通过 REST API 在 C# 中将图像上传到 ServiceNow答案

【问题标题】：Uploading image to ServiceNow in C# via REST API通过 REST API 在 C# 中将图像上传到 ServiceNow
【发布时间】：2021-05-09 00:51:44
【问题描述】：

我正在尝试使用此链接中提供的 SNow API 将图像上传到 ServiceNow 事件： https://developer.servicenow.com/dev.do#!/reference/api/orlando/rest/c_AttachmentAPI#r_AttachmentAPI-POSTmultipart

我在下面写了C# 代码来发布图片：

    string url = "https://mycompany.service-now.com/api/now/attachment/upload/"
        , userName = "MyUser", passwd = "MyPassword";

    var httpClientHandler = new HttpClientHandler()
    {
        Credentials = new NetworkCredential(userName, passwd),
    };

    using (var httpClient = new HttpClient(httpClientHandler))
    {

        // Add an Accept header for JSON format.
        httpClient.DefaultRequestHeaders.Accept.Clear();
        httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

        var multipartContent = new MultipartFormDataContent();
        multipartContent.Headers.TryAddWithoutValidation("Content-Type", "multipart/form-data");
        multipartContent.Add(new StringContent("incident"), "table_name");
        multipartContent.Add(new StringContent("f264fd3a1bghghgjjhg8f7b4bcbb6"), "table_sys_id"); // id of my incident
        multipartContent.Add(new ByteArrayContent(File.ReadAllBytes("D:\\MyImage.jpeg")), "uploadFile", "MyImage.jpeg");

        var response = httpClient.PostAsync(new Uri(url), multipartContent).Result;
        string result = response.Content.ReadAsStringAsync().Result;
        MessageBox.Show(result);
    }

但是，我不断得到：

请求的 URI 不代表任何资源

可能是什么问题以及如何相应地调整代码？

【问题讨论】：

只需从您的 url 中删除尾随“/” - string url = "mycompany.service-now.com/api/now/attachment/upload"
@Sergey 做到了，现在收到一条新消息：Failed to create the attachment. File part might be missing in the request :(
你必须发一条新消息。
你的意思是使用另一个事件？
对代码进行了一些更改，在标题中的键周围添加了双引号。我将发布新代码

标签： c# api httpclient servicenow servicenow-rest-api

【解决方案1】：

在删除url 末尾的“/”之后，并在我从这篇文章中读到的标题中的键周围添加双引号：

https://community.servicenow.com/community?id=community_question&sys_id=328614ffdb00eb808e7c2926ca9619ad&view_source=searchResult

最终的工作代码是：

string url = "https://mycompany.service-now.com/api/now/attachment/upload"
    , userName = "MyUser", passwd = "MyPassword";

var httpClientHandler = new HttpClientHandler()
{
    Credentials = new NetworkCredential(userName, passwd),
};

using (var httpClient = new HttpClient(httpClientHandler))
{

    // Add an Accept header for JSON format.
    httpClient.DefaultRequestHeaders.Accept.Clear();
    httpClient.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

    var fileStream = new ByteArrayContent(File.ReadAllBytes("D:\\Image.jpeg"));
            fileStream.Headers.Remove("Content-Type");
            fileStream.Headers.Add("Content-Type", "application/octet-stream");
            fileStream.Headers.Add("Content-Transfer-Encoding", "binary");
            fileStream.Headers.Add("Content-Disposition", $"form-data;name=\"uploadFile\"; filename=\"{"Image.jpeg"}\"");

            var multipartContent = new MultipartFormDataContent();
            multipartContent.Add(new StringContent("incident"), "\"table_name\"");
            multipartContent.Add(new StringContent("f264fd3a1bghghgjjhg8f7b4bcbb6"), "\"table_sys_id\"");
            multipartContent.Add(fileStream, "uploadFile");

    var response = httpClient.PostAsync(new Uri(url), multipartContent).Result;
    string result = response.Content.ReadAsStringAsync().Result;
    MessageBox.Show(result);
}

【讨论】：