GraphQL教程(二) .net Core api 2.1
阿新 • • 發佈：2018-12-30
一、編輯Schema資料夾內容
真正的GraphQL教程才剛剛開始QWQ，怕了吧，Schema的資料夾才是關於Graph的
置於GraphQL是什麼,一種用於 API 的查詢語言
GraphQL 既是一種用於 API 的查詢語言也是一個滿足你資料查詢的執行時。 GraphQL 對你的 API 中的資料提供了一套易於理解的完整描述，使得客戶端能夠準確地獲得它需要的資料，而且沒有任何冗餘，也讓 API 更容易地隨著時間推移而演進，還能用於構建強大的開發者工具。
據我所知的是GraphQL由facebook所製造，現階段github等一群大佬企業也在用這個
在類庫schema資料夾中新增三個類MovieType,ActorType,MovieRatingEnum
其中MovieRatingEnum是列舉型別，其他的你可以一一對應下
程式碼看不看的懂，看不懂就對了，不然你也不用學了，直接抄吧，抄個一兩遍就有感悟了，到時候再去官網逛逛提升下自己
首先編寫MovieRatingEnum類，直接上程式碼
using GraphQL.Types; using GraphStudy.Movies.Movies; namespace GraphStudy.Movies.Schema { public class MovieRatingEnum:EnumerationGraphType<MovieRatingEnum> { //先定義下建構函式,列表列舉的GraphQL public MovieRatingEnum() { Name = "MovieRating";//型別的名字 Description = "";//型別的描述 //將滑鼠置於AddValue上顯示name,description,value,[deprecationReason] []的含義是可填可不填的意思 AddValue(MovieRating.Unrated.ToString(), "Unrated",MovieRating.Unrated); AddValue(MovieRating.G.ToString(), "G", MovieRating.G); AddValue(MovieRating.PG.ToString(), "PG", MovieRating.PG); AddValue(MovieRating.PG13.ToString(), "PG13", MovieRating.PG13); AddValue(MovieRating.R.ToString(), "R", MovieRating.R); AddValue(MovieRating.NC17.ToString(), "NC17", MovieRating.NC17); } } }
編寫ActorType類，直接上程式碼
using GraphQL.Types; using GraphStudy.Movies.Movies; namespace GraphStudy.Movies.Schema { public class ActorType:ObjectGraphType<Actor> { public ActorType() { Field(x => x.Id); Field(x => x.Name); } } }
編寫MovieType類
using GraphQL.Types;
using GraphStudy.Movies.Movies;
using GraphStudy.Movies.Services;
namespace GraphStudy.Movies.Schema
{
public class MovieType:ObjectGraphType<Movie>
{
//先定義下建構函式
public MovieType(IActorService actorService)
{
Name = "Movie";//型別的名字
Description = "";//型別的描述
Field(x => x.Id);
Field(x => x.Name);
Field(x => x.Company);
Field(x => x.ReleaseDate);
Field(x => x.ActorId);
//將列舉的Graph也加入其中,這是在查詢Movie中巢狀（學過sql應該懂得巢狀查詢）一個MovieRatingEnum
//取名movieRating，查詢結果context.Source.MovieRating
Field<MovieRatingEnum>("movieRating", resolve: context => context.Source.MovieRating);
Field<ActorType>("Actor", resolve: context => actorService.GetByIdAsync(context.Source.ActorId));
//做一個小小的測試
Field<StringGraphType>("customString", resolve: context => "1234");
}
}
}
在Schema資料夾中進行新增查詢類MoviesQuery
using GraphQL.Types;
using GraphStudy.Movies.Services;
namespace GraphStudy.Movies.Schema
{
//查詢
class MoviesQuery:ObjectGraphType
{
public MoviesQuery(IMovieService movieService)
{
Name = "Query";
//查詢所有Movie
Field<ListGraphType<MovieType>>("movies", resolve: context => movieService.GetAsyncs());
}
}
}
在Service資料夾內新增MovieSchema類，以後的增刪改查都在此新增服務
using GraphQL;
namespace GraphStudy.Movies.Schema
{
class MovieSchema:GraphQL.Types.Schema
{
public MovieSchema(IDependencyResolver dependencyResolver, MoviesQuery moviesQuery)
{
DependencyResolver = dependencyResolver;
Query = moviesQuery;
}
}
}
在startup新增服務
services.AddSingleton<ActorType>();
services.AddSingleton<MovieRatingEnum>();
services.AddSingleton<MovieType>();
services.AddSingleton<MoviesQuery>();
services.AddSingleton<MovieSchema>();
services.AddSingleton<IDependencyResolver>(s => new FuncDependencyResolver(s.GetRequiredService));
2.呼叫GraphQL 的UI介面
進入GraphQL的github
https://github.com/graphql-dotnet
找到這個
GraphStudy.Api在NuGet程式包新增這三個包
GraphQL.Server.Transports.AspNetCore
GraphQL.Server.Transports.WebSockets
GraphQL.Server.Ui.Playground
將途中的複製下來
startup全部程式碼
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using GraphQL;
using GraphQL.Server;
using GraphQL.Server.Ui.Playground;
using GraphStudy.Movies.Schema;
using GraphStudy.Movies.Services;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.DependencyInjection;
namespace GraphStudy.Api
{
public class Startup
{
// This method gets called by the runtime. Use this method to add services to the container.
// For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=398940
public void ConfigureServices(IServiceCollection services)
{
services.AddSingleton<IMovieService, MovieService>();
services.AddSingleton<IActorService, ActorService>();
services.AddSingleton<ActorType>();
services.AddSingleton<MovieRatingEnum>();
services.AddSingleton<MovieType>();
services.AddSingleton<MoviesQuery>();
services.AddSingleton<MovieSchema>();
services.AddSingleton<IDependencyResolver>(s => new FuncDependencyResolver(s.GetRequiredService));
// Add GraphQL services and configure options
services.AddGraphQL(options =>
{
options.EnableMetrics = true;
options.ExposeExceptions = true;//是否包容異常，改下
})
.AddWebSockets() // Add required services for web socket support
.AddDataLoader(); // Add required services for DataLoader support
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
// this is required for websockets support
app.UseWebSockets();
// use websocket middleware for ChatSchema at path /graphql
app.UseGraphQLWebSockets<MovieSchema>("/graphql");
// use HTTP middleware for ChatSchema at path /graphql
app.UseGraphQL<MovieSchema>("/graphql");
//去點另外兩個UI，因為我們剛剛新增的包就是Playground，所以保留這個就行
// use graphql-playground middleware at default url /ui/playground
app.UseGraphQLPlayground(new GraphQLPlaygroundOptions());
}
}
}
執行成功
query{
movies{
id
name
company
movieRating
releaseDate
actorId
customString
}
}
是類似sql的查詢語句，GraphQL獨有
可參閱官方學習，或者以後教
https://github.com/1045683477/GraphQL-
這是到現在的寫的,程式碼在GitHub上