使用Rest API开发SharePoint Online

一、首先需要在扩展中引用3个dll：

System.Net.Http;

Microsoft.SharePoint.Client;

Microsoft.SharePoint.Client.Runtime;

在Nuget中安装Newtonsoft.dll

二、再新建两个类：

SPHttpClient.cs

using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Net.Http.Headers;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

namespace Call_SharePoint_Restful
{
/// <summary>
/// Http client for SharePoint Online
/// </summary>
public class SPHttpClient : HttpClient
{

public SPHttpClient(Uri webUri, string userName, string password)
: base(new SPHttpClientHandler(webUri, userName, password))
{
BaseAddress = webUri;
}

/// <summary>
/// Execure request method
/// </summary>
/// <param name="requestUri"></param>
/// <param name="method"></param>
/// <param name="headers"></param>
/// <param name="payload"></param>
/// <returns></returns>
public JObject ExecuteJson<T>(string requestUri, HttpMethod method, IDictionary<string, string> headers, T payload)
{
HttpResponseMessage response;
switch (method.Method)
{
case "POST":
var requestContent = new StringContent(JsonConvert.SerializeObject(payload));
requestContent.Headers.ContentType = MediaTypeHeaderValue.Parse("application/json;odata=verbose");
DefaultRequestHeaders.Add("X-RequestDigest", RequestFormDigest());
if (headers != null)
{
foreach (var header in headers)
{
DefaultRequestHeaders.Add(header.Key, header.Value);
}
}
response = PostAsync(requestUri, requestContent).Result;
break;
case "GET":
response = GetAsync(requestUri).Result;
break;
default:
throw new NotSupportedException(string.Format("Method {0} is not supported", method.Method));
}

response.EnsureSuccessStatusCode();
var responseContent = response.Content.ReadAsStringAsync().Result;
return String.IsNullOrEmpty(responseContent) ? new JObject() : JObject.Parse(responseContent);
}

public JObject ExecuteJson<T>(string requestUri, HttpMethod method, T payload)
{
return ExecuteJson(requestUri, method, null, payload);
}

public JObject ExecuteJson(string requestUri)
{
return ExecuteJson(requestUri, HttpMethod.Get, null, default(string));
}

/// <summary>
/// Request Form Digest
/// </summary>
/// <returns></returns>
public string RequestFormDigest()
{
var endpointUrl = string.Format("{0}/_api/contextinfo", BaseAddress);
var result = this.PostAsync(endpointUrl, new StringContent(string.Empty)).Result;
result.EnsureSuccessStatusCode();
var content = result.Content.ReadAsStringAsync().Result;
var contentJson = JObject.Parse(content);
return contentJson["d"]["GetContextWebInformation"]["FormDigestValue"].ToString();
}
}
}

SPHttpClientHandler.cs

using System;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Security;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.SharePoint.Client;

namespace Call_SharePoint_Restful
{
public class SPHttpClientHandler : HttpClientHandler
{
public SPHttpClientHandler(Uri webUri, string userName, string password)
{
CookieContainer = GetAuthCookies(webUri, userName, password);
FormatType = FormatType.JsonVerbose;
}

protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
request.Headers.Add("X-FORMS_BASED_AUTH_ACCEPTED", "f");
if (FormatType == FormatType.JsonVerbose)
{
//request.Headers.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json;odata=verbose"));
request.Headers.Add("Accept", "application/json;odata=verbose");
}
return base.SendAsync(request, cancellationToken);
}

/// <summary>
/// Retrieve SPO Auth Cookies
/// </summary>
/// <param name="webUri"></param>
/// <param name="userName"></param>
/// <param name="password"></param>
/// <returns></returns>
private static CookieContainer GetAuthCookies(Uri webUri, string userName, string password)
{
var securePassword = new SecureString();
foreach (var c in password) {
securePassword.AppendChar(c);
}
var credentials = new SharePointOnlineCredentials(userName, securePassword);
var authCookie = credentials.GetAuthenticationCookie(webUri);
var cookieContainer = new CookieContainer();
cookieContainer.SetCookies(webUri, authCookie);
return cookieContainer;
}

public FormatType FormatType { get; set; }
}

public enum FormatType
{
JsonVerbose,
Xml
}
}

三、以下是调用的代码：

如何获取所有列表项

using (var client = new SPHttpClient(webUri, userName, password))
{
var listTitle = "Tasks";
var endpointUrl = string.Format("{0}/_api/web/lists/getbytitle('{1}')/items",webUri,listTitle);
var data = client.ExecuteJson(endpointUrl);
foreach (var item in data["value"])
{
Console.WriteLine(item["Title"]);
}
}

如何获取指定的列表项

using (var client = new SPHttpClient(webUri, userName, password))
{
var listTitle = "Tasks";
var itemId = 1;
var endpointUrl = string.Format("{0}/_api/web/lists/getbytitle('{1}')/items({2})",webUri,listTitle,itemId);
var data = client.ExecuteJson(endpointUrl);
Console.WriteLine(data["Title"]);
}

如何创建列表项

using (var client = new SPHttpClient(webUri, userName, password))
{
var listTitle = "Tasks";
var itemPayload = new { __metadata = new { type = "SP.Data.TasksListItem" }, Title = "Approval Task"};
var endpointUrl = string.Format("{0}/_api/web/lists/getbytitle('{1}')/items",webUri,listTitle);
var data = client.ExecuteJson(endpointUrl,HttpMethod.Post,itemPayload);
Console.WriteLine("Task item '{0}' has been created",data["Title"]);
}

如何更新列表项

using (var client = new SPHttpClient(webUri, userName, password))
{
var listTitle = "Tasks";
var itemId = 1;
var itemPayload = new { __metadata = new { type = "SP.Data.TasksListItem" }, Title = "Approval Task"};
var endpointUrl = string.Format("{0}/_api/web/lists/getbytitle('{1}')/items({2})",webUri,listTitle,itemId);
var headers = new Dictionary<string,string>();
headers["IF-MATCH"] = "*";
headers["X-HTTP-Method"] = "MERGE";
client.ExecuteJson(endpointUrl,HttpMethod.Post,headers, itemPayload);
Console.WriteLine("Task item has been updated");
}

如何删除列表项

using (var client = new SPHttpClient(webUri, userName, password))
{
var listTitle = "Tasks";
var itemId = 2;
var endpointUrl = string.Format("{0}/_api/web/lists/getbytitle('{1}')/items({2})",webUri,listTitle,itemId);
var headers = new Dictionary<string,string>();
headers["IF-MATCH"] = "*";
headers["X-HTTP-Method"] = "DELETE";
client.ExecuteJson(endpointUrl,HttpMethod.Post,null,headers);
Console.WriteLine("Task item has been deleted");
}

原文：https://blog.vgrem.com/2015/04/04/consume-sharepoint-online-rest-service-using-net/