.NetCore2.1 WebAPI 根据swagger.json自动生成客户端代码

前言

上一篇博客中我们可以得知通过Swagger插件可以很方便的提供给接口开发者在线调试，但是实际上Swagger附带的功能还有很多，

比如使用NSwag生成客户端调用代码，进一步解放接口开发者。

NSwag

NSwag是一个发布在GitHub上的开源项目，它可以根据Swagger说明页上的swagger.json文件生成C#、TypeScript客户端代码。

NSwag的项目地址:https://github.com/RSuter/NSwag

Nswag提供4种代码生成方法

1、使用 NSwagStudio，这是一款 Windows 桌面应用，用于在 C# 和 TypeScript 中为 API 生成客户端代码。

2、使用 NSwag.CodeGeneration.CSharp 或 NSwag.CodeGeneration.TypeScript NuGet 包在项目中执行代码生成。

3、使用命令行中的 NSwag。

4、使用 NSwag.MSBuild NuGet 包。

这里推荐使用NSwagStudio，可以从GitHub上下载该工具，地址:https://github.com/RSuter/NSwag/wiki/NSwagStudio

下载后开始安装，安装完毕后打开NSwagStudio，如下图，在左侧选择Tab页菜单里选择Documents

如上图框框选中的几点，我们需要留意。其中Swagger Specification URL就是我们WebAPI的swagger.json的在线地址。

如果点击【Create local Copy 】按钮时你的WebAPI未在线则代码生成工具会弹出错误对话框，如下图:

所以采取读取Swagger Specification URL 方式进行生成代码的前提条件是你必须保证swagger.json文件能在线读取！

其次你可以选择RunTime（运行时），这里应该是服务端WebAPI的运行时(毕竟TypeScript是不关心你服务端是.NET Core还是.NET Framework).

因为我的环境是.NET Core2.1，所以这里选择NET Core21。

接下来，点击【Create local Copy】按钮，点击后NSwagStudio会与WebAPI服务端进行交互，成功后会将swagger.json文件格式化到左边的文本编辑器中，如下图:

此时，你可以在右侧的Outputs中勾选你需要输出的文件格式，这里我选择TypeScript和CSharp Client，

这个地方有个C# WebAPI Controller，我有点纳闷，我都有swagger.json文件了绝壁是已经存在webapi了，

没有必要反向再去生成一遍webapi的控制器啦。 不懂，反正只管生成客户端代码就好。

我们勾选好后下面就会出现相应的输出配合页面，如下图:

我们选择CSharp Client页面，该页面左侧分为Setting和Output两个页面，Setting页可以对输出的cs文件进行配置，如命名空间、类名称、输出文件路径等等(很多配置我也不会....)

我们点击【Generate Outputs】后NSwagStudio会根据配置生成客户端操作类，在Output页面即可检查，检查无误后再点击【Generate Files】可将类文件导出到配置的输出目录。

TypeScript亦是如此，同时NSwagStudio也可支持加载DLL反射生成，具体方法可根据官网操作(毕竟可以直接使用json文件在线生成没必要再自己手工选择dll..)

这里截图看SwagerUI页和NSwagStudio生成后的客户端cs文件

生成的客户端C#代码：

//----------------------
// <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测试</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测试</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;
        }
    }

}

在线生成客户端|服务端调用代码

如果嫌代码生成工具需要下载或你们前端的电脑操作系统是MacOs则可以考虑使用Swagger在线代码生成，地址: https://editor.swagger.io/

Swagger线上代码生成支持导入swagger.json文件和引用SwaggerUI线上地址两种模式。

推荐使用Import File，我使用Import URL压根就没成功过。。。。

导入方法如下图

导入后可以选择导出的方式(服务端 OR 客户端)，并且这个比前面的代码生成器exe要强大啊，它支持导出的语言真是把我惊呆了，牛逼啊。

没图我会乱说？？ 是不是很牛逼。

选择生成后，浏览器就会下载代码啦~~~~~~真的牛批啊~~！~！！！

给你们贴一张线上生成TypeScript-angular的代码，真的比那个exe生成出来的代码规范多了，线上生成的会根据每一个Controller生成一个Service.ts，

exe工具是把所有Controllser的action都生成在一个Service.ts文件里(尼玛，这也能不同。。我还是以后都从线上生成算了....)

结语

不得不赞叹Swagger的强大，它的出现解放了多少程序员啊，后续但凡有客户端码农说不会调用哥的API，哥都可以直接给他代码生成器生成的代码，一个字：爽。