使用C# HttpClient登录Salesforce

using System;
using System.Net.Http;
using System.Threading.Tasks;

HttpClient client = new HttpClient();

string loginUrl = "https://login.salesforce.com/services/oauth2/token";
string clientId = "Your_Client_Id";
string clientSecret = "Your_Client_Secret";
string username = "Your_Salesforce_Username";
string password = "Your_Salesforce_Password";
string securityToken = "Your_Salesforce_Security_Token";
string grantType = "password";
string requestContent = $"grant_type={grantType}&client_id={clientId}&client_secret={clientSecret}&username={username}&password={password}{securityToken}";

HttpResponseMessage response = await client.PostAsync(loginUrl, new StringContent(requestContent));
string responseContent = await response.Content.ReadAsStringAsync();

string accessToken = "";
if (response.IsSuccessStatusCode)
{
    // 解析响应内容，获取访问令牌
    // 这里使用JSON解析库进行解析，比如Newtonsoft.Json
    dynamic jsonResponse = Newtonsoft.Json.JsonConvert.DeserializeObject(responseContent);
    accessToken = jsonResponse.access_token;
}

if (!string.IsNullOrEmpty(accessToken))
{
    // 在这里可以使用访问令牌进行Salesforce的其他操作，比如查询数据、创建记录等
    // 例如：
    // string queryUrl = "https://your_salesforce_instance_url/services/data/vXX.X/query?q=SELECT+Id,Name+FROM+Account";
    // client.DefaultRequestHeaders.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", accessToken);
    // HttpResponseMessage queryResponse = await client.GetAsync(queryUrl);
    // string queryResponseContent = await queryResponse.Content.ReadAsStringAsync();
}