网站编辑做的准备,外贸建站公司排名,个人建设什么网站,广西网站建设哪里有问题在业务开发中#xff0c;对Web API的返回格式有一定要求#xff0c;需要是定制化的Json结构#xff0c;用于前端统一处理#xff1a;{Status : 0,Message: ,Info : xxx
}Status表示响应的状态码#xff0c;0为成功#xff1b;Message表示错误消息#x… 问题在业务开发中对Web API的返回格式有一定要求需要是定制化的Json结构用于前端统一处理{Status : 0,Message: ,Info : xxx
}
Status表示响应的状态码0为成功Message表示错误消息Status不为0时返回Info表示API返回的实际数据Json格式简单实现当然你可以定义一个数据结构作为每个API的返回值public class ResponseDataT
{public int Status { get; set; } 0;public string Message { get; set; }public T Info { get; set; }public ResponseData(T obj){Info obj;}
}[HttpGet]
public ResponseDataIEnumerableWeatherForecast Get()
{var rng new Random();var data Enumerable.Range(1, 5).Select(index new WeatherForecast{Date DateTime.Now.AddDays(index),TemperatureC rng.Next(-20, 55),Summary Summaries[rng.Next(Summaries.Length)]}).ToArray();return new ResponseDataIEnumerableWeatherForecast(data);
}
但是如果这样实现每一个API方法都必须修改实例化一个ResponseData对象返回。如果以后业务修改要移除这个自定义结构又是件麻烦事。有没有一劳永逸、并且更加优雅的实现方式呢自定义响应内容既然这个Json结构是在原有的返回数据外围再包了一层那么我们直接获取Web API的原始Response.Body然后格式化成新的JSon在赋值给Response.Body不就可以了 但是实际验证时发现在.NET 5下已经无法改写无任何数据返回。示例代码如下app.Use(async (context, next)
{var newContent string.Empty;using (var newBody new MemoryStream()){context.Response.Body newBody;await next();context.Response.Body new MemoryStream();newBody.Seek(0, SeekOrigin.Begin);newContent new StreamReader(newBody).ReadToEnd();newContent , World!;await context.Response.WriteAsync(newContent);}
});
难道这条路走不通IHttpResponseBodyFeature在aspnetcore的源代码中找到了ResponseCompressionMiddlewarehttps://github.com/dotnet/aspnetcore/blob/main/src/Middleware/ResponseCompression/src/ResponseCompressionMiddleware.cs。它是用来处理响应压缩的中间件也就是说对响应做了处理看看它的实现方式public async Task Invoke(HttpContext context)
{if (!_provider.CheckRequestAcceptsCompression(context)){await _next(context);return;}var originalBodyFeature context.Features.GetIHttpResponseBodyFeature();var originalCompressionFeature context.Features.GetIHttpsCompressionFeature();Debug.Assert(originalBodyFeature ! null);var compressionBody new ResponseCompressionBody(context, _provider, originalBodyFeature);context.Features.SetIHttpResponseBodyFeature(compressionBody);context.Features.SetIHttpsCompressionFeature(compressionBody);try{await _next(context);await compressionBody.FinishCompressionAsync();}finally{context.Features.Set(originalBodyFeature);context.Features.Set(originalCompressionFeature);}
}
它将IHttpResponseBodyFeature进行了替换context.Features.SetIHttpResponseBodyFeature(compressionBody);
那IHttpResponseBodyFeature到底是个什么玩意“ASP.NET Core 中的请求功能”https://docs.microsoft.com/zh-cn/aspnet/core/fundamentals/request-features?viewaspnetcore-5.0作出了相应的解释 ASP.NET Core 在 Microsoft.AspNetCore.Http.Features 中定义了许多常见的 HTTP 功能接口各种服务器和中间件共享这些接口来标识其支持的功能。服务器和中间件还可以提供自己的具有附加功能的接口。 ResponseCustomBody那我们就依葫芦画瓢实现我们的ResponseCustomBody:public class ResponseCustomBody : Stream, IHttpResponseBodyFeature
{private readonly HttpContext _context;private readonly IHttpResponseBodyFeature _innerBodyFeature;private readonly Stream _innerStream;public ResponseCustomBody(HttpContext context,IHttpResponseBodyFeature innerBodyFeature){_context context;_innerBodyFeature innerBodyFeature;_innerStream innerBodyFeature.Stream;} public Stream Stream this;public PipeWriter Writer throw new NotImplementedException();public override bool CanRead false;public override bool CanSeek false;public override bool CanWrite _innerStream.CanWrite;public override long Length throw new NotImplementedException();public override long Position { get throw new NotImplementedException(); set throw new NotImplementedException(); }public async Task CompleteAsync(){await _innerBodyFeature.CompleteAsync();}public void DisableBuffering(){_innerBodyFeature.DisableBuffering();}public Task SendFileAsync(string path, long offset, long? count, CancellationToken cancellationToken default){return _innerBodyFeature.SendFileAsync(path, offset, count, cancellationToken);}public Task StartAsync(CancellationToken cancellationToken default){return _innerBodyFeature.StartAsync(cancellationToken);}public override void Flush(){_innerStream.Flush();}public override int Read(byte[] buffer, int offset, int count){throw new NotImplementedException();}public override long Seek(long offset, SeekOrigin origin){throw new NotImplementedException();}public override void SetLength(long value){throw new NotImplementedException();}public override async Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken){var json System.Text.Encoding.UTF8.GetString(buffer).TrimEnd(\0);json {\Status\:0, \Info\: json };buffer System.Text.Encoding.UTF8.GetBytes(json);count buffer.Length;await _innerStream.WriteAsync(buffer, offset, count, cancellationToken);}public override void Write(byte[] buffer, int offset, int count){throw new NotImplementedException();}
}
关键代码就是下面这段我们取出原始响应内容格式化后再写入public override async Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
{var json System.Text.Encoding.UTF8.GetString(buffer).TrimEnd(\0);json {\Status\:0, \Info\: json };buffer System.Text.Encoding.UTF8.GetBytes(json);count buffer.Length;await _innerStream.WriteAsync(buffer, offset, count, cancellationToken);
}
最后我们再定义一个中间件使用ResponseCustomBody替换IHttpResponseBodyFeaturepublic class ResponseCustomMiddleware : IMiddleware
{public async Task InvokeAsync(HttpContext context, RequestDelegate next){var originalBodyFeature context.Features.GetIHttpResponseBodyFeature();var customBody new ResponseCustomBody(context, originalBodyFeature);context.Features.SetIHttpResponseBodyFeature(customBody);try{await next(context);}finally{context.Features.Set(originalBodyFeature);}}
}
运行效果也能满足我们的要求 结论在本文中我们利用了ASP.NET Core的功能接口实现了自定义格式响应。你也可以尝试使用功能接口实现一些有用的功能。如果你觉得这篇文章对你有所启发请关注我的个人公众号”My IO“记住我
