通過jQuery和C#分別實現對.NET Core Web Api的訪問以及文件上傳

準備工作：建立.NET Core Web Api項目新建一個用於Api請求的UserInfo類 2、建立.NET Core Web項目一、使用jQuery Ajax訪問（一）、表單 [FromForm] 數據類型：Object ContenyType類型：application/x-www- ...

準備工作：

　　　建立.NET Core Web Api項目

　　　新建一個用於Api請求的UserInfo類

    public class UserInfo
    {
        public string name { get; set; }
        public int age { get; set; }
        public bool sex { get; set; }
    }

　　2、建立.NET Core Web項目

一、使用jQuery Ajax訪問

（一）、表單　　　　　 [FromForm]

數據類型：Object

ContenyType類型：application/x-www-form-urlencoded

 var model = { name: "劉大大", age: 23, sex: true };

前臺請求

        var model = { name: "劉大大", age: 23, sex: true };       
        $.ajax({
            url: "http://localhost:57954/API/Default/data",
            type: "POST",
            async: true,
            dataType: "json",
            data: model,
            contentType: "application/x-www-form-urlencoded",
            success: function (data) {
                console.log("data:");
                console.log(data);
            }
        });

後臺接受

（二）、JSON字元串　　[FromBdy]

數據類型：Json

ContenyType類型：application/json

var json={"name":"劉大大","age":23,"sex":true}

也可以使用JSON.stringify(Object)將Object轉換為JSON字元串

前端請求

        var model = { name: "劉大大", age: 23, sex: true };       
        $.ajax({
            url: "http://localhost:57954/API/Default/data",
            type: "POST",
            async: true,
            dataType: "json",
            data: JSON.stringify(model),
            contentType: "application/json",
            success: function (data) {
                console.log("data:");
                console.log(data);
            }
        });

後臺接受

（三）、文件上傳

建立FormData對象

數據類型：FromData

ContenyType類型false, //必須false才會避開jQuery對 formdata 的預設處理
processData類型: false, //必須false才會自動加上正確的Content-Type

html

 <input type="file" multiple id="file" />

JS獲取文件對象

        var file = document.getElementById("file");
        var files = file.files;
        var formData = new FormData();
        for (var i = 0; i < files.length; i++) {
            formData.append(files[i].name, files[i]);
        }
　　　　 formData.append("name", "劉大大");//可追加參數

AJAX請求

        $.ajax({
            url: "http://localhost:57954/API/Default/data",
            type: "POST",
            async: true,
            dataType: "json",
            data: formData,
            contentType: false, 
            processData: false,
            success: function (data) {
                console.log("data:");
                console.log(data);
            }
        });

後臺接受

追加的name參數

傳輸的文件

二、使用C#後臺訪問

（一）、Get訪問

var url = "http://localhost:57954/API/Default/values";

using (var client = new HttpClient(new HttpClientHandler() { AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip }))
{
var taskResponse = client.GetAsync(url);
taskResponse.Wait();
if (taskResponse.IsCompletedSuccessfully)
{
var taskStream = taskResponse.Result.Content.ReadAsStreamAsync();
taskStream.Wait();
using (var reader = new StreamReader(taskStream.Result))
{
jsonString = reader.ReadToEnd();
}
}
}

（二）、Post訪問

            var data = new {name="劉大大",age=23,sex=true };
            using (var client = new HttpClient(new HttpClientHandler() { AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip }))
            {
                var jsonToSend = JsonConvert.SerializeObject(data, Formatting.None, new IsoDateTimeConverter());
                var body = new StringContent(jsonToSend, Encoding.UTF8, "application/json");
                var taskResponse = client.PostAsync(url, body);
                taskResponse.Wait();
                if (taskResponse.IsCompletedSuccessfully)
                {
                    var taskStream = taskResponse.Result.Content.ReadAsStreamAsync();
                    taskStream.Wait();
                    using (var reader = new StreamReader(taskStream.Result))
                    {
                        jsonString = reader.ReadToEnd();
                    }
                }
            }

（三）、上傳文件

        public IActionResult Upload()
        {

            var url = "http://localhost:57954/API/Default/values";

            var data = new MultipartFormDataContent();
            if (Request.HasFormContentType)
            {
                var request = Request.Form.Files;
                foreach (var item in request)
                {
                    data.Add(new StreamContent(item.OpenReadStream()), item.Name, item.FileName);
                }

                foreach (var item in Request.Form)
                {
                    data.Add(new StringContent(item.Value), item.Key);
                }
            }
            string jsonString;
            using (var client = new HttpClient(new HttpClientHandler() { AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip }))
            {
                var taskResponse = client.PostAsync(url, data);
                taskResponse.Wait();
                if (taskResponse.IsCompletedSuccessfully)
                {
                    var taskStream = taskResponse.Result.Content.ReadAsStreamAsync();
                    taskStream.Wait();
                    using (var reader = new StreamReader(taskStream.Result))
                    {
                        jsonString = reader.ReadToEnd();
                    }
                }
            }
            return Json("OK");
        }

View Code

WebHelper

這裡包含了WebRequest和HttpClient兩種請求方式，以及包含了將Object對象序列化為HttpCotnent對象的方法。

/***************************************************************************************************************************************************
 * *文件名：WebHelper.cs
 * *創建人：Jon
 * *日 期 ：2018年5月25日
 * *描 述 ：實現HTTP協議中的GET、POST請求
 * *MVC使用HttpClient上傳文件實例：      
        public IActionResult Upload()
        {

            var url = "http://localhost:57954/API/Default/values";
            var data = new MultipartFormDataContent();
            if (Request.HasFormContentType)
            {
                var request = Request.Form.Files;
                foreach (var item in request)
                {
                    data.Add(new StreamContent(item.OpenReadStream()), item.Name, item.FileName);
                }

                foreach (var item in Request.Form)
                {
                    data.Add(new StringContent(item.Value), item.Key);
                }
            }
            WebHelper.PostByHttpClientFromHttpContent(url, data);
            return Json("OK");
        }
*****************************************************************************************************************************************************/
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;

namespace Expansion.Helper
{
    public static class WebHelper
    {
        /// <summary>
        /// 通過WebRequest發起Get請求
        /// </summary>
        /// <param name="url">請求地址</param>
        /// <returns>JSON字元串</returns>
        public static string GetByWebRequest(string url)
        {
            string jsonString = string.Empty;
            var request = (HttpWebRequest)WebRequest.Create(url);
            request.Method = "GET";
            request.ContentType = "application/json";
            request.AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip;
            var response = (HttpWebResponse)request.GetResponse();
            using (var stream = new StreamReader(response.GetResponseStream()))
            {
                jsonString = stream.ReadToEnd();
            }
            return jsonString;
        }

        /// <summary>
        /// 通過WebRequest發起Post請求
        /// </summary>
        /// <param name="url">請求地址</param>
        /// <param name="data">請求參數</param>
        /// <returns>JSON字元串</returns>
        public static string PostByWebRequest(string url, object data)
        {
            string jsonString = string.Empty;
            var request = (HttpWebRequest)WebRequest.Create(url);
            request.ContentType = "application/json";
            request.Method = "POST";
            request.Timeout = Int32.MaxValue;
            request.AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip;
            var jsonToSend = JsonConvert.SerializeObject(data, Formatting.None, new IsoDateTimeConverter());
            byte[] btBodys = Encoding.UTF8.GetBytes(jsonToSend);
            request.ContentLength = btBodys.Length;
            request.GetRequestStream().Write(btBodys, 0, btBodys.Length);
            var response = (HttpWebResponse)request.GetResponse();
            using (var stream = new StreamReader(response.GetResponseStream()))
            {
                jsonString = stream.ReadToEnd();
            }
            return jsonString;
        }


        /// <summary>
        /// 通過HttpClient發起Get請求
        /// </summary>
        /// <param name="url">請求地址</param>
        /// <returns>JSON字元串</returns>
        public static string GetByHttpClient(string url)
        {
            string jsonString = string.Empty;
            using (var client = new HttpClient(new HttpClientHandler() { AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip }))
            {
                var taskResponse = client.GetAsync(url);
                taskResponse.Wait();
                if (taskResponse.IsCompletedSuccessfully)
                {
                    var taskStream = taskResponse.Result.Content.ReadAsStreamAsync();
                    taskStream.Wait();
                    using (var reader = new StreamReader(taskStream.Result))
                    {
                        jsonString = reader.ReadToEnd();
                    }
                }
            }
            return jsonString;
        }

        /// <summary>
        /// 通過HttpClient發起Post請求
        /// </summary>
        /// <param name="url">請求地址</param>
        /// <param name="data">請求參數</param>
        /// <returns>JSON字元串</returns>
        public static string PostByHttpClient(string url, object data)
        {
            string jsonString = string.Empty;
            using (var client = new HttpClient(new HttpClientHandler() { AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip }))
            {
                var jsonToSend = JsonConvert.SerializeObject(data, Formatting.None, new IsoDateTimeConverter());
                var body = new StringContent(jsonToSend, Encoding.UTF8, "application/json");
                var taskResponse = client.PostAsync(url, body);
                taskResponse.Wait();
                if (taskResponse.IsCompletedSuccessfully)
                {
                    var taskStream = taskResponse.Result.Content.ReadAsStreamAsync();
                    taskStream.Wait();
                    using (var reader = new StreamReader(taskStream.Result))
                    {
                        jsonString = reader.ReadToEnd();
                    }
                }
            }
            return jsonString;
        }

        /// <summary>
        /// 通過數據來自HttpContent的HttpClient發起Post請求
        /// </summary>
        /// <param name="url">請求地址</param>
        /// <param name="content">請求參數</param>
        /// <returns>JSON字元串</returns>
        public static string PostByHttpClientFromHttpContent(string url, HttpContent content)
        {
            string jsonString = string.Empty;
            using (var client = new HttpClient(new HttpClientHandler() { AutomaticDecompression = DecompressionMethods.Deflate | DecompressionMethods.GZip }))
            {
                var taskResponse = client.PostAsync(url, content);
                taskResponse.Wait();
                if (taskResponse.IsCompletedSuccessfully)
                {
                    var taskStream = taskResponse.Result.Content.ReadAsStreamAsync();
                    taskStream.Wait();
                    using (var reader = new StreamReader(taskStream.Result))
                    {
                        jsonString = reader.ReadToEnd();
                    }
                }
            }
            return jsonString;
        }

        /// <summary>
        /// Object轉換為StreamContent
        /// </summary>
        /// <param name="data">請求參數</param>
        /// <returns>StreamContent</returns>
        public static HttpContent ToStreamContent(this object data)
        {

            var json = JsonConvert.SerializeObject(data, Formatting.None, new IsoDateTimeConverter());
            byte[] bytes = Encoding.UTF8.GetBytes(json);
            MemoryStream ms = new MemoryStream();
            ms.Write(bytes, 0, bytes.Length);
            ms.Position = 0;
            HttpContent streamContent = new StreamContent(ms);
            return streamContent;
        }

        /// <summary>
        /// Object轉換為StringContent
        /// </summary>
        /// <param name="data">請求參數</param>
        /// <returns>StringContent</returns>
        public static HttpContent ToStringContent(this object data)
        {
            HttpContent stringContent = new StringContent(JsonConvert.SerializeObject(data));
            return stringContent;
        }

        /// <summary>
        /// Object轉換為MultipartFormDataContent
        /// </summary>
        /// <param name="data"></param>
        /// <returns>MultipartFormDataContent</returns>
        public static HttpContent ToMultipartFormDataContent(this object data)
        {
            var json = JsonConvert.SerializeObject(data, Formatting.None, new IsoDateTimeConverter());
            var body = new StringContent(json, Encoding.UTF8, "application/json");
            var multipartFormDataContent = new MultipartFormDataContent();
            multipartFormDataContent.Add(body);
            return multipartFormDataContent;
        }

        /// <summary>
        /// Object轉換為FormUrlEncodedContent
        /// </summary>
        /// <param name="data">請求參數</param>
        /// <returns>FormUrlEncodedContent</returns>
        public static HttpContent ToFormUrlEncodedContent(this object data)
        {
            var param = new List<KeyValuePair<string, string>>();
            var values = JObject.FromObject(data);
            foreach (var item in values)
            {
                param.Add(new KeyValuePair<string, string>(item.Key, item.Value.ToString()));
            }
            HttpContent formUrlEncodedContent = new FormUrlEncodedContent(param);
            return formUrlEncodedContent;
        }


        /// <summary>
        /// Object轉換為ByteArrayContent
        /// </summary>
        /// <param name="data">請求參數</param>
        /// <returns>FormUrlEncodedContent</returns>
        public static HttpContent ToByteArrayContent(this object data)
        {
            var json = JsonConvert.SerializeObject(data, Formatting.None, new IsoDateTimeConverter());
            byte[] bytes = Encoding.UTF8.GetBytes(json);
            HttpContent byteArrayContent = new ByteArrayContent(bytes);
            return byteArrayContent;
        }

        /// <summary>
        /// Url編碼
        /// </summary>
        /// <param name="content">內容</param>
        /// <param name="encode">編碼類型</param>
        /// <returns></returns>
        private static string Encode(string content, Encoding encode = null)
        {
            if (encode == null) return content;

            return System.Web.HttpUtility.UrlEncode(content, Encoding.UTF8);

        }


        /// <summary>
        /// Url解碼
        /// </summary>
        /// <param name="content">內容</param>
        /// <param name="encode">編碼類型</param>
        /// <returns></returns>
        private static string Decode(string content, Encoding encode = null)
        {
            if (encode == null) return content;

            return System.Web.HttpUtility.UrlDecode(content, Encoding.UTF8);

        }

        /// <summary>
        /// 將鍵值對參數集合拼接為Url字元串
        /// </summary>
        /// <param name="paramArray">鍵值對集合</param>
        /// <param name="encode">轉碼類型</param>
        /// <returns></returns>
        private static string BuildParam(List<KeyValuePair<string, string>> paramArray, Encoding encode = null)
        {
            string url = "";

            if (encode == null) encode = Encoding.UTF8;

            if (paramArray != null && paramArray.Count > 0)
            {
                var parms = "";
                foreach (var item in paramArray)
                {
                    parms += string.Format("{0}={1}&", Encode(item.Key, encode), Encode(item.Value, encode));
                }
                if (parms != "")
                {
                    parms = parms.TrimEnd('&');
                }
                url += parms;

            }
            return url;
        }
    }
}

View Code

時間倉促，沒能說的太詳細，有時間再做補充。如本文中的有錯誤示範，歡迎指正