这篇博客是上篇博客的续写，上篇博客用的是HttpClient取远程数据，用WebRequest提交，更新，删除数据。
今天进行了一下修改，全程用的都是HttpClient
说一下实现过程吧。
在实现的过程中，我发现了PostAsync和PutAsync需要的参数都是一个类型的，DeleteAsyc和GetAsync需要的参数都是一个类型的。那么这就省很多事了只用一个方法+反射，里边再加一个if{...}else{...}就可解决四个问题了。
主要就是添加了HandleDataFactoryAsync这个方法里边注释写的很详细。
/// <summary>
/// 这是用HttpClient调用Web Api实现CRUD到数据库中
/// </summary>
/// <param name="u">数据</param>
/// <param name="url">请求的url</param>
/// <param name="RequestType">请求的类型</param>
/// <returns></returns>
private async Task<string> HandleDataFactoryAsync(Users u, string url, string RequestType)
{
//声明一个HttpClient类
HttpClient client = new HttpClient();
//将Users转化为JSon字符串
string jsonString = UsersConvertToJson(u);
//声明一个String类型的Context在提交数据时需要用到这个参数
var context = new StringContent(jsonString, Encoding.UTF8, "application/json");
//设置反射需要获取的方法名称
string method = RequestType + "Async"; //我这里将两步写在了一起
//1.通过获取所有的方法
//2.通过linq语句查询我需要的方法
//当然也可以直接GetMethod(MethodName)
//我感觉那样的话可能会抛“方法找不到”的异常
//我用Linq查询避免了
MethodInfo info = client.GetType().GetMethods().FirstOrDefault(m => m.Name == method);
if (info != null)
{
HttpResponseMessage result; //由于put和post需要的参数类型和数目一致所以放在一块处理了
//get和delete也一样
if (method == "PutAsync" || method == "PostAsync")
{
//激活这个方法并且传递所需要的参数
result= await (Task<HttpResponseMessage>)info.Invoke(client, new Object[] { url, context });
}
else
{
result = await (Task<HttpResponseMessage>)info.Invoke(client, new Object[] { url });
}
//将响应内容返回
return await result.Content.ReadAsStringAsync(); } return ""; }
修改用法
/// <summary>
/// 传递数据到远程API的数据库中
/// </summary>
/// <param name="u"></param>
/// <returns></returns>
private async Task<string> CreateAsync(Users u)
{
string url = baseURL;
string requestMethod = "Post";
//return await HandleDataAsync(u, url, requestMethod);
return await HandleDataFactoryAsync(u, url, requestMethod);
} private async Task<string> UpdateAsync(Users u)
{
string url = baseURL + @"/" + u.ID;
string requestMethod = "Put";
// return await HandleDataAsync(u, url, requestMethod);
return await HandleDataFactoryAsync(u, url, requestMethod);
}
private async Task<string> DeleteAsync(Users u)
{
string url = baseURL + @"/" + u.ID;
string requestMethod = "Delete";
//return await HandleDataAsync(u, url, requestMethod);
return await HandleDataFactoryAsync(u, url, requestMethod); }
注释掉的那行是原来调用WebRequest的方法，别的都没有改变。
这是整个类
using Microsoft.AspNetCore.Mvc;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;
using TestAPI.Models; namespace TestAPI.Controllers
{
public class UsersController : Controller
{
#region 成员变量
//这个baseURL是我的webApi的地址
private static string baseURL = "http://localhost:56853/api/users";
//用于存放所有的用户
private static IList<Users> _context; #endregion #region 构造函数
public UsersController()
{
//实例化对象
_context = new List<Users>();
//获取所有的用户的信息
_context = GetAllUserList(); } #endregion #region 类内方法 /// <summary>
/// 通过api获取所有的用户的信息
/// </summary>
/// <returns>JSON String</returns>
private string GetALLUserInfoFromAPI()
{
HttpClient client = new HttpClient();
var con = client.GetStringAsync(baseURL);
return con.Result; } private string UsersConvertToJson(Users u)
{
return JsonConvert.SerializeObject(u);
}
/// <summary>
/// 传递数据到远程API的数据库中
/// </summary>
/// <param name="u"></param>
/// <returns></returns>
private async Task<string> CreateAsync(Users u)
{
string url = baseURL;
string requestMethod = "Post";
//return await HandleDataAsync(u, url, requestMethod);
return await HandleDataFactoryAsync(u, url, requestMethod);
} private async Task<string> UpdateAsync(Users u)
{
string url = baseURL + @"/" + u.ID;
string requestMethod = "Put";
// return await HandleDataAsync(u, url, requestMethod);
return await HandleDataFactoryAsync(u, url, requestMethod);
}
private async Task<string> DeleteAsync(Users u)
{
string url = baseURL + @"/" + u.ID;
string requestMethod = "Delete";
//return await HandleDataAsync(u, url, requestMethod);
return await HandleDataFactoryAsync(u, url, requestMethod); }
private bool UsersExist(int iD)
{
return _context.Any(u => u.ID == iD);
}
/// <summary>
/// 用WebRequest处理数据
/// </summary>
/// <param name="Data">User实体类</param>
/// <param name="Url">远程API的URL</param>
/// <param name="RequestMethod">请求的方法</param>
/// <returns></returns>
private async Task<string> HandleDataAsync(Users Data, string Url, string RequestMethod)
{
string UsersJson = UsersConvertToJson(Data);
var request = WebRequest.CreateHttp(Url);
request.Accept = "application/json";
//下边这行不设置会出现无法识别mediaType 415 这个错误
request.ContentType = "application/json";
request.Method = RequestMethod;
//向request提交数据
using (StreamWriter writer = new StreamWriter(await request.GetRequestStreamAsync()))
{
writer.Write(UsersJson);
}
//获取响应
var reponse = await request.GetResponseAsync();
//返回响应数据
using (StreamReader reader = new StreamReader(reponse.GetResponseStream()))
{
return reader.ReadToEnd();
}
} /// <summary>
/// 这是用HttpClient调用Web Api实现CRUD到数据库中
/// </summary>
/// <param name="u">数据</param>
/// <param name="url">请求的url</param>
/// <param name="RequestType">请求的类型</param>
/// <returns></returns>
private async Task<string> HandleDataFactoryAsync(Users u, string url, string RequestType)
{
//声明一个HttpClient类
HttpClient client = new HttpClient();
//将Users转化为JSon字符串
string jsonString = UsersConvertToJson(u);
//声明一个String类型的Context在提交数据时需要用到这个参数
var context = new StringContent(jsonString, Encoding.UTF8, "application/json");
//设置反射需要获取的方法名称
string method = RequestType + "Async"; //我这里将两步写在了一起
//1.通过获取所有的方法
//2.通过linq语句查询我需要的方法
//当然也可以直接GetMethod(MethodName)
//我感觉那样的话可能会抛“方法找不到”的异常
//我用Linq查询避免了
MethodInfo info = client.GetType().GetMethods().FirstOrDefault(m => m.Name == method);
if (info != null)
{
HttpResponseMessage result; //由于put和post需要的参数类型和数目一致所以放在一块处理了
//get和delete也一样
if (method == "PutAsync" || method == "PostAsync")
{
//激活这个方法并且传递所需要的参数
result= await (Task<HttpResponseMessage>)info.Invoke(client, new Object[] { url, context });
}
else
{
result = await (Task<HttpResponseMessage>)info.Invoke(client, new Object[] { url });
}
//将响应内容返回
return await result.Content.ReadAsStringAsync(); } return ""; }
/// <summary>
/// 获取所有用户的List
/// </summary>
private IList<Users> GetAllUserList()
{
IList<Users> userslist = new List<Users>();
var JsonString = GetALLUserInfoFromAPI();
JArray UsersArray = JArray.Parse(JsonString);
for (int i = ; i < UsersArray.Count; i++)
{
userslist.Add(StringConvertToUser(UsersArray[i].ToString()));
}
return userslist;
}
/// <summary>
/// 将Json对象的字符串转化为users对象
/// </summary>
/// <param name="JsonString">json对象的字符串</param>
/// <returns>Users对象</returns>
private Users StringConvertToUser(string JsonString)
{
return JsonConvert.DeserializeObject<Users>(JsonString);
}
#endregion #region Index
// GET: Users
public async Task<IActionResult> Index()
{
return View(_context);
} #endregion #region Details // GET: Users/Details/5
public async Task<IActionResult> Details(int? id)
{
if (id == null)
{
return BadRequest();
}
var users = _context.FirstOrDefault(u => u.ID == id);
if (users == null)
{
return NotFound();
}
return View(users);
} #endregion #region Create // GET: Users/Create
public IActionResult Create()
{
return View();
} // POST: Users/Create
// To protect from overposting attacks, please enable the specific properties you want to bind to, for
// more details see http://go.microsoft.com/fwlink/?LinkId=317598.
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Create([Bind("ID,name,pwd")] Users users)
{
if (ModelState.IsValid)
{ await CreateAsync(users);
return RedirectToAction("Index");
}
return View();
} #endregion #region Edit // GET: Users/Edit/5
public async Task<IActionResult> Edit(int? id)
{
if (id == null)
{
return BadRequest();
}
var users = _context.FirstOrDefault(u => u.ID == id);
if (users == null)
{
return NotFound();
}
return View(users);
} // POST: Users/Edit/5
// To protect from overposting attacks, please enable the specific properties you want to bind to, for
// more details see http://go.microsoft.com/fwlink/?LinkId=317598.
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Edit(int id, [Bind("ID,name,pwd")] Users users)
{ if (ModelState.IsValid)
{
if (id != users.ID)
{
return BadRequest();
}
try
{
await UpdateAsync(users);
return RedirectToAction("Index");
}
catch
{
if (UsersExist(users.ID))
{
return NotFound();
}
throw;
} }
return View();
} #endregion #region Delete // GET: Users/Delete/5
public async Task<IActionResult> Delete(int? id)
{
if (id == null)
{
return BadRequest();
}
var users = _context.FirstOrDefault(u => u.ID == id);
if (users == null)
{
return NotFound();
} return View(users);
} // POST: Users/Delete/5
[HttpPost, ActionName("Delete")]
[ValidateAntiForgeryToken]
public async Task<IActionResult> DeleteConfirmed(int id)
{
var users = _context.SingleOrDefault(u => u.ID == id);
await DeleteAsync(users);
return RedirectToAction("Index");
}
#endregion }
}
UsersController.cs
感觉HttpClient比WebRequest好用一点。毕竟都差不多吧，只不过是是现的方式不一样，用法不一样。又让我体验了一把反射的魅力。
这个是连接Web Api的git地址 https://github.com/1483523635/dotNetCoreAPIDemoTest
这个是用到的Web Api的git地址https://github.com/1483523635/dotNetCoreAPIDemo