前言上一篇博客中我們可以得知通過Swagger插件可以很方便的提供給介面開發者線上調試，但是實際上Swagger附帶的功能還有很多，比如使用NSwag生成客戶端調用代碼，進一步解放介面開發者。 NSwag NSwag是一個發佈在GitHub上的開源項目，它可以根據Swagger說明頁上的swag ...

前言

上一篇博客中我們可以得知通過Swagger插件可以很方便的提供給介面開發者線上調試，但是實際上Swagger附帶的功能還有很多，

比如使用NSwag生成客戶端調用代碼，進一步解放介面開發者。

NSwag

NSwag是一個發佈在GitHub上的開源項目，它可以根據Swagger說明頁上的swagger.json文件生成C#、TypeScript客戶端代碼。

NSwag的項目地址:https://github.com/RSuter/NSwag

Nswag提供4種代碼生成方法

1、使用 NSwagStudio，這是一款 Windows 桌面應用，用於在 C# 和 TypeScript 中為 API 生成客戶端代碼。

2、使用 NSwag.CodeGeneration.CSharp 或 NSwag.CodeGeneration.TypeScript NuGet 包在項目中執行代碼生成。

3、使用命令行中的 NSwag。

4、使用 NSwag.MSBuild NuGet 包。

這裡推薦使用NSwagStudio，可以從GitHub上下載該工具，地址:https://github.com/RSuter/NSwag/wiki/NSwagStudio

下載後開始安裝，安裝完畢後打開NSwagStudio，如下圖，在左側選擇Tab頁菜單里選擇Documents

如上圖框框選中的幾點，我們需要留意。其中Swagger Specification URL就是我們WebAPI的swagger.json的線上地址。

如果點擊【Create local Copy 】按鈕時你的WebAPI未線上則代碼生成工具會彈出錯誤對話框，如下圖:

所以採取讀取Swagger Specification URL 方式進行生成代碼的前提條件是你必須保證swagger.json文件能線上讀取！

其次你可以選擇RunTime（運行時），這裡應該是服務端WebAPI的運行時(畢竟TypeScript是不關心你服務端是.NET Core還是.NET Framework).

因為我的環境是.NET Core2.1，所以這裡選擇NET Core21。

接下來，點擊【Create local Copy】按鈕，點擊後NSwagStudio會與WebAPI服務端進行交互，成功後會將swagger.json文件格式化到左邊的文本編輯器中，如下圖:

此時，你可以在右側的Outputs中勾選你需要輸出的文件格式，這裡我選擇TypeScript和CSharp Client，

這個地方有個C# WebAPI Controller，我有點納悶，我都有swagger.json文件了絕壁是已經存在webapi了，

沒有必要反向再去生成一遍webapi的控制器啦。不懂，反正只管生成客戶端代碼就好。

我們勾選好後下麵就會出現相應的輸出配合頁面，如下圖:

我們選擇CSharp Client頁面，該頁面左側分為Setting和Output兩個頁面，Setting頁可以對輸出的cs文件進行配置，如命名空間、類名稱、輸出文件路徑等等(很多配置我也不會....)

我們點擊【Generate Outputs】後NSwagStudio會根據配置生成客戶端操作類，在Output頁面即可檢查，檢查無誤後再點擊【Generate Files】可將類文件導出到配置的輸出目錄。

TypeScript亦是如此，同時NSwagStudio也可支持載入DLL反射生成，具體方法可根據官網操作(畢竟可以直接使用json文件線上生成沒必要再自己手工選擇dll..)

這裡截圖看SwagerUI頁和NSwagStudio生成後的客戶端cs文件

生成的客戶端C#代碼：

//----------------------
// <auto-generated>
//     Generated using the NSwag toolchain v11.17.19.0 (NJsonSchema v9.10.58.0 (Newtonsoft.Json v9.0.0.0)) (http://NSwag.org)
// </auto-generated>
//----------------------

namespace Test
{
    #pragma warning disable // Disable all warnings

    [System.CodeDom.Compiler.GeneratedCode("NSwag", "11.17.19.0 (NJsonSchema v9.10.58.0 (Newtonsoft.Json v9.0.0.0))")]
    public  partial class Client 
    {
        private string _baseUrl = "http://localhost:58985";
        private System.Lazy<Newtonsoft.Json.JsonSerializerSettings> _settings;
    
        public Client()
        {
            _settings = new System.Lazy<Newtonsoft.Json.JsonSerializerSettings>(() => 
            {
                var settings = new Newtonsoft.Json.JsonSerializerSettings();
                UpdateJsonSerializerSettings(settings);
                return settings;
            });
        }
    
        public string BaseUrl 
        {
            get { return _baseUrl; }
            set { _baseUrl = value; }
        }
    
        protected Newtonsoft.Json.JsonSerializerSettings JsonSerializerSettings { get { return _settings.Value; } }
    
        partial void UpdateJsonSerializerSettings(Newtonsoft.Json.JsonSerializerSettings settings);
        partial void PrepareRequest(System.Net.Http.HttpClient client, System.Net.Http.HttpRequestMessage request, string url);
        partial void PrepareRequest(System.Net.Http.HttpClient client, System.Net.Http.HttpRequestMessage request, System.Text.StringBuilder urlBuilder);
        partial void ProcessResponse(System.Net.Http.HttpClient client, System.Net.Http.HttpResponseMessage response);
    
        /// <summary>巴拉巴拉</summary>
        /// <returns>Success</returns>
        /// <exception cref="SwaggerException">A server side error occurred.</exception>
        public System.Threading.Tasks.Task ApiTestGetAsync()
        {
            return ApiTestGetAsync(System.Threading.CancellationToken.None);
        }
    
        /// <summary>巴拉巴拉</summary>
        /// <returns>Success</returns>
        /// <exception cref="SwaggerException">A server side error occurred.</exception>
        /// <param name="cancellationToken">A cancellation token that can be used by other objects or threads to receive notice of cancellation.</param>
        public async System.Threading.Tasks.Task ApiTestGetAsync(System.Threading.CancellationToken cancellationToken)
        {
            var urlBuilder_ = new System.Text.StringBuilder();
            urlBuilder_.Append(BaseUrl != null ? BaseUrl.TrimEnd('/') : "").Append("/api/Test");
    
            var client_ = new System.Net.Http.HttpClient();
            try
            {
                using (var request_ = new System.Net.Http.HttpRequestMessage())
                {
                    request_.Method = new System.Net.Http.HttpMethod("GET");
    
                    PrepareRequest(client_, request_, urlBuilder_);
                    var url_ = urlBuilder_.ToString();
                    request_.RequestUri = new System.Uri(url_, System.UriKind.RelativeOrAbsolute);
                    PrepareRequest(client_, request_, url_);
    
                    var response_ = await client_.SendAsync(request_, System.Net.Http.HttpCompletionOption.ResponseHeadersRead, cancellationToken).ConfigureAwait(false);
                    try
                    {
                        var headers_ = System.Linq.Enumerable.ToDictionary(response_.Headers, h_ => h_.Key, h_ => h_.Value);
                        if (response_.Content != null && response_.Content.Headers != null)
                        {
                            foreach (var item_ in response_.Content.Headers)
                                headers_[item_.Key] = item_.Value;
                        }
    
                        ProcessResponse(client_, response_);
    
                        var status_ = ((int)response_.StatusCode).ToString();
                        if (status_ == "200") 
                        {
                            return;
                        }
                        else
                        if (status_ != "200" && status_ != "204")
                        {
                            var responseData_ = response_.Content == null ? null : await response_.Content.ReadAsStringAsync().ConfigureAwait(false); 
                            throw new SwaggerException("The HTTP status code of the response was not expected (" + (int)response_.StatusCode + ").", (int)response_.StatusCode, responseData_, headers_, null);
                        }
                    }
                    finally
                    {
                        if (response_ != null)
                            response_.Dispose();
                    }
                }
            }
            finally
            {
                if (client_ != null)
                    client_.Dispose();
            }
        }
    
        /// <returns>Success</returns>
        /// <exception cref="SwaggerException">A server side error occurred.</exception>
        public System.Threading.Tasks.Task ApiTestPostAsync(string value)
        {
            return ApiTestPostAsync(value, System.Threading.CancellationToken.None);
        }
    
        /// <returns>Success</returns>
        /// <exception cref="SwaggerException">A server side error occurred.</exception>
        /// <param name="cancellationToken">A cancellation token that can be used by other objects or threads to receive notice of cancellation.</param>
        public async System.Threading.Tasks.Task ApiTestPostAsync(string value, System.Threading.CancellationToken cancellationToken)
        {
            var urlBuilder_ = new System.Text.StringBuilder();
            urlBuilder_.Append(BaseUrl != null ? BaseUrl.TrimEnd('/') : "").Append("/api/Test");
    
            var client_ = new System.Net.Http.HttpClient();
            try
            {
                using (var request_ = new System.Net.Http.HttpRequestMessage())
                {
                    var content_ = new System.Net.Http.StringContent(Newtonsoft.Json.JsonConvert.SerializeObject(value, _settings.Value));
                    content_.Headers.ContentType = System.Net.Http.Headers.MediaTypeHeaderValue.Parse("multipart/form-data");
                    request_.Content = content_;
                    request_.Method = new System.Net.Http.HttpMethod("POST");
    
                    PrepareRequest(client_, request_, urlBuilder_);
                    var url_ = urlBuilder_.ToString();
                    request_.RequestUri = new System.Uri(url_, System.UriKind.RelativeOrAbsolute);
                    PrepareRequest(client_, request_, url_);
    
                    var response_ = await client_.SendAsync(request_, System.Net.Http.HttpCompletionOption.ResponseHeadersRead, cancellationToken).ConfigureAwait(false);
                    try
                    {
                        var headers_ = System.Linq.Enumerable.ToDictionary(response_.Headers, h_ => h_.Key, h_ => h_.Value);
                        if (response_.Content != null && response_.Content.Headers != null)
                        {
                            foreach (var item_ in response_.Content.Headers)
                                headers_[item_.Key] = item_.Value;
                        }
    
                        ProcessResponse(client_, response_);
    
                        var status_ = ((int)response_.StatusCode).ToString();
                        if (status_ == "200") 
                        {
                            return;
                        }
                        else
                        if (status_ != "200" && status_ != "204")
                        {
                            var responseData_ = response_.Content == null ? null : await response_.Content.ReadAsStringAsync().ConfigureAwait(false); 
                            throw new SwaggerException("The HTTP status code of the response was not expected (" + (int)response_.StatusCode + ").", (int)response_.StatusCode, responseData_, headers_, null);
                        }
                    }
                    finally
                    {
                        if (response_ != null)
                            response_.Dispose();
                    }
                }
            }
            finally
            {
                if (client_ != null)
                    client_.Dispose();
            }
        }
    
        /// <summary>我是get測試</summary>
        /// <returns>Success</returns>
        /// <exception cref="SwaggerException">A server side error occurred.</exception>
        public System.Threading.Tasks.Task<string> ApiTestByIdGetAsync(int id)
        {
            return ApiTestByIdGetAsync(id, System.Threading.CancellationToken.None);
        }
    
        /// <summary>我是get測試</summary>
        /// <returns>Success</returns>
        /// <exception cref="SwaggerException">A server side error occurred.</exception>
        /// <param name="cancellationToken">A cancellation token that can be used by other objects or threads to receive notice of cancellation.</param>
        public async System.Threading.Tasks.Task<string> ApiTestByIdGetAsync(int id, System.Threading.CancellationToken cancellationToken)
        {
            if (id == null)
                throw new System.ArgumentNullException("id");
    
            var urlBuilder_ = new System.Text.StringBuilder();
            urlBuilder_.Append(BaseUrl != null ? BaseUrl.TrimEnd('/') : "").Append("/api/Test/{id}");
            urlBuilder_.Replace("{id}", System.Uri.EscapeDataString(ConvertToString(id, System.Globalization.CultureInfo.InvariantCulture)));
    
            var client_ = new System.Net.Http.HttpClient();
            try
            {
                using (var request_ = new System.Net.Http.HttpRequestMessage())
                {
                    request_.Method = new System.Net.Http.HttpMethod("GET");
                    request_.Headers.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
    
                    PrepareRequest(client_, request_, urlBuilder_);
                    var url_ = urlBuilder_.ToString();
                    request_.RequestUri = new System.Uri(url_, System.UriKind.RelativeOrAbsolute);
                    PrepareRequest(client_, request_, url_);
    
                    var response_ = await client_.SendAsync(request_, System.Net.Http.HttpCompletionOption.ResponseHeadersRead, cancellationToken).ConfigureAwait(false);
                    try
                    {
                        var headers_ = System.Linq.Enumerable.ToDictionary(response_.Headers, h_ => h_.Key, h_ => h_.Value);
                        if (response_.Content != null && response_.Content.Headers != null)
                        {
                            foreach (var item_ in response_.Content.Headers)
                                headers_[item_.Key] = item_.Value;
                        }
    
                        ProcessResponse(client_, response_);
    
                        var status_ = ((int)response_.StatusCode).ToString();
                        if (status_ == "200") 
                        {
                            var responseData_ = response_.Content == null ? null : await response_.Content.ReadAsStringAsync().ConfigureAwait(false); 
                            var result_ = default(string); 
                            try
                            {
                                result_ = Newtonsoft.Json.JsonConvert.DeserializeObject<string>(responseData_, _settings.Value);
                                return result_; 
                            } 
                            catch (System.Exception exception_) 
                            {
                                throw new SwaggerException("Could not deserialize the response body.", (int)response_.StatusCode, responseData_, headers_, exception_);
                            }
                        }
                        else
                        if (status_ != "200" && status_ != "204")
                        {
                            var responseData_ = response_.Content == null ? null : await response_.Content.ReadAsStringAsync().ConfigureAwait(false); 
                            throw new SwaggerException("The HTTP status code of the response was not expected (" + (int)response_.StatusCode + ").", (int)response_.StatusCode, responseData_, headers_, null);
                        }
            
                        return default(string);
                    }
                    finally
                    {
                        if (response_ != null)
                            response_.Dispose();
                    }
                }
            }
            finally
            {
                if (client_ != null)
                    client_.Dispose();
            }
        }
    
        /// <returns>Success</returns>
        /// <exception cref="SwaggerException">A server side error occurred.</exception>
        public System.Threading.Tasks.Task ApiTestByIdPutAsync(int id, string value)
        {
            return ApiTestByIdPutAsync(id, value, System.Threading.CancellationToken.None);
        }
    
        /// <returns>Success</returns>
        /// <exception cref="SwaggerException">A server side error occurred.</exception>
        /// <param name="cancellationToken">A cancellation token that can be used by other objects or threads to receive notice of cancellation.</param>
        public async System.Threading.Tasks.Task ApiTestByIdPutAsync(int id, string value, System.Threading.CancellationToken cancellationToken)
        {
            if (id == null)
                throw new System.ArgumentNullException("id");
    
            var urlBuilder_ = new System.Text.StringBuilder();
            urlBuilder_.Append(BaseUrl != null ? BaseUrl.TrimEnd('/') : "").Append("/api/Test/{id}");
            urlBuilder_.Replace("{id}", System.Uri.EscapeDataString(ConvertToString(id, System.Globalization.CultureInfo.InvariantCulture)));
    
            var client_ = new System.Net.Http.HttpClient();
            try
            {
                using (var request_ = new System.Net.Http.HttpRequestMessage())
                {
                    var content_ = new System.Net.Http.StringContent(Newtonsoft.Json.JsonConvert.SerializeObject(value, _settings.Value));
                    content_.Headers.ContentType = System.Net.Http.Headers.MediaTypeHeaderValue.Parse("multipart/form-data");
                    request_.Content = content_;
                    request_.Method = new System.Net.Http.HttpMethod("PUT");
    
                    PrepareRequest(client_, request_, urlBuilder_);
                    var url_ = urlBuilder_.ToString();
                    request_.RequestUri = new System.Uri(url_, System.UriKind.RelativeOrAbsolute);
                    PrepareRequest(client_, request_, url_);
    
                    var response_ = await client_.SendAsync(request_, System.Net.Http.HttpCompletionOption.ResponseHeadersRead, cancellationToken).ConfigureAwait(false);
                    try
                    {
                        var headers_ = System.Linq.Enumerable.ToDictionary(response_.Headers, h_ => h_.Key, h_ => h_.Value);
                        if (response_.Content != null && response_.Content.Headers != null)
                        {
                            foreach (var item_ in response_.Content.Headers)
                                headers_[item_.Key] = item_.Value;
                        }
    
                        ProcessResponse(client_, response_);
    
                        var status_ = ((int)response_.StatusCode).ToString();
                        if (status_ == "200") 
                        {
                            return;
                        }
                        else
                        if (status_ != "200" && status_ != "204")
                        {
                            var responseData_ = response_.Content == null ? null : await response_.Content.ReadAsStringAsync().ConfigureAwait(false); 
                            throw new SwaggerException("The HTTP status code of the response was not expected (" + (int)response_.StatusCode + ").", (int)response_.StatusCode, responseData_, headers_, null);
                        }
                    }
                    finally
                    {
                        if (response_ != null)
                            response_.Dispose();
                    }
                }
            }
            finally
            {
                if (client_ != null)
                    client_.Dispose();
            }
        }
    
        /// <summary>小魔仙</summary>
        /// <returns>Success</returns>
        /// <exception cref="SwaggerException">A server side error occurred.</exception>
        public System.Threading.Tasks.Task ApiTestByIdDeleteAsync(int id)
        {
            return ApiTestByIdDeleteAsync(id, System.Threading.CancellationToken.None);
        }
    
        /// <summary>小魔仙</summary>
        /// <returns>Success</returns>
        /// <exception cref="SwaggerException">A server side error occurred.</exception>
        /// <param name="cancellationToken">A cancellation token that can be used by other objects or threads to receive notice of cancellation.</param>
        public async System.Threading.Tasks.Task ApiTestByIdDeleteAsync(int id, System.Threading.CancellationToken cancellationToken)
        {
            if (id == null)
                throw new System.ArgumentNullException("id");
    
            var urlBuilder_ = new System.Text.StringBuilder();
            urlBuilder_.Append(BaseUrl != null ? BaseUrl.TrimEnd('/') : "").Append("/api/Test/{id}");
            urlBuilder_.Replace("{id}", System.Uri.EscapeDataString(ConvertToString(id, System.Globalization.CultureInfo.InvariantCulture)));
    
            var client_ = new System.Net.Http.HttpClient();
            try
            {
                using (var request_ = new System.Net.Http.HttpRequestMessage())
                {
                    request_.Method = new System.Net.Http.HttpMethod("DELETE");
    
                    PrepareRequest(client_, request_, urlBuilder_);
                    var url_ = urlBuilder_.ToString();
                    request_.RequestUri = new System.Uri(url_, System.UriKind.RelativeOrAbsolute);
                    PrepareRequest(client_, request_, url_);
    
                    var response_ = await client_.SendAsync(request_, System.Net.Http.HttpCompletionOption.ResponseHeadersRead, cancellationToken).ConfigureAwait(false);
                    try
                    {
                        var headers_ = System.Linq.Enumerable.ToDictionary(response_.Headers, h_ => h_.Key, h_ => h_.Value);
                        if (response_.Content != null && response_.Content.Headers != null)
                        {
                            foreach (var item_ in response_.Content.Headers)
                                headers_[item_.Key] = item_.Value;
                        }
    
                        ProcessResponse(client_, response_);
    
                        var status_ = ((int)response_.StatusCode).ToString();
                        if (status_ == "200") 
                        {
                            return;
                        }
                        else
                        if (status_ != "200" && status_ != "204")
                        {
                            var responseData_ = response_.Content == null ? null : await response_.Content.ReadAsStringAsync().ConfigureAwait(false); 
                            throw new SwaggerException("The HTTP status code of the response was not expected (" + (int)response_.StatusCode + ").", (int)response_.StatusCode, responseData_, headers_, null);
                        }
                    }
                    finally
                    {
                        if (response_ != null)
                            response_.Dispose();
                    }
                }
            }
            finally
            {
                if (client_ != null)
                    client_.Dispose();
            }
        }
    
        private string ConvertToString(object value, System.Globalization.CultureInfo cultureInfo)
        {
            if (value is System.Enum)
            {
                string name = System.Enum.GetName(value.GetType(), value);
                if (name != null)
                {
                    var field = System.Reflection.IntrospectionExtensions.GetTypeInfo(value.GetType()).GetDeclaredField(name);
                    if (field != null)
                    {
                        var attribute = System.Reflection.CustomAttributeExtensions.GetCustomAttribute(field, typeof(System.Runtime.Serialization.EnumMemberAttribute)) 
                            as System.Runtime.Serialization.EnumMemberAttribute;
                        if (attribute != null)
                        {
                            return attribute.Value;
                        }
                    }
                }
            }
            else if (value is byte[])
            {
                return System.Convert.ToBase64String((byte[]) value);
            }
            else if (value != null && value.GetType().IsArray)
            {
                var array = System.Linq.Enumerable.OfType<object>((System.Array) value);
                return string.Join(",", System.Linq.Enumerable.Select(array, o => ConvertToString(o, cultureInfo)));
            }
        
            return System.Convert.ToString(value, cultureInfo);
        }
    }
    
    

    

    [System.CodeDom.Compiler.GeneratedCode("NSwag", "11.17.19.0 (NJsonSchema v9.10.58.0 (Newtonsoft.Json v9.0.0.0))")]
    public partial class SwaggerException : System.Exception
    {
        public int StatusCode { get; private set; }

        public string Response { get; private set; }

        public System.Collections.Generic.Dictionary<string, System.Collections.Generic.IEnumerable<string>> Headers { get; private set; }

        public SwaggerException(string message, int statusCode, string response, System.Collections.Generic.Dictionary<string, System.Collections.Generic.IEnumerable<string>> headers, System.Exception innerException) 
            : base(message, innerException)
        {
            StatusCode = statusCode;
            Response = response; 
            Headers = headers;
        }

        public override string ToString()
        {
            return string.Format("HTTP Response: \n\n{0}\n\n{1}", Response, base.ToString());
        }
    }

    [System.CodeDom.Compiler.GeneratedCode("NSwag", "11.17.19.0 (NJsonSchema v9.10.58.0 (Newtonsoft.Json v9.0.0.0))")]
    public partial class SwaggerException<TResult> : SwaggerException
    {
        public TResult Result { get; private set; }

        public SwaggerException(string message, int statusCode, string response, System.Collections.Generic.Dictionary<string, System.Collections.Generic.IEnumerable<string>> headers, TResult result, System.Exception innerException) 
            : base(message, statusCode, response, headers, innerException)
        {
            Result = result;
        }
    }

}

結語

不得不贊嘆Swagger的強大，它的出現解放了多少程式員啊，後續但凡有客戶端碼農說不會調用哥的API，哥都可以直接給他代碼生成器生成的代碼，一個字：爽。

.NetCore2.1 WebAPI 根據swagger.json自動生成客戶端代碼

前言

NSwag

結語