.net core讀取json格式的配置檔案
阿新 • • 發佈:2018-12-26
在.Net Framework中,配置檔案一般採用的是XML格式的,.NET Framework提供了專門的ConfigurationManager來讀取配置檔案的內容,.net core中推薦使用json格式的配置檔案,那麼在.net core中該如何讀取json檔案呢?
1、在Startup類中讀取json配置檔案
1、使用Configuration直接讀取
看下面的程式碼:
public IConfiguration Configuration { get; }
Configuration屬性就是.net core中提供的用來讀取json檔案。例如:
publicvoid Configure(IApplicationBuilder app, IHostingEnvironment env) { string option1 = $"option1 = {this.Configuration["Option1"]}"; string option2 = $"option2 = {this.Configuration["Option2"]}"; string suboption1 = $"suboption1 = {this.Configuration["subsection:suboption1"]}"; // 讀取陣列 string name1 = $"Name={this.Configuration["student:0:Name"]} "; string age1 = $"Age= {this.Configuration["student:0:Age"]}"; string name2 = $"Name={this.Configuration["student:1:Name"]}"; string age2 = $"Age= {this.Configuration["student:1:Age"]}"; // 輸出 app.Run(c => c.Response.WriteAsync(option1+"\r\n"+option2+ "\r\n"+suboption1+ "\r\n"+name1+ "\r\n"+age1+ "\r\n"+name2+ "\r\n"+age2)); if (env.IsDevelopment()) { app.UseDeveloperExceptionPage(); } else { app.UseHsts(); } app.UseHttpsRedirection(); app.UseMvc(); }
結果:
2、使用IOptions介面
1、定義實體類
public class MongodbHostOptions { /// <summary> /// 連線字串 /// </summary> public string Connection { get; set; } /// <summary> /// 庫 /// </summary> public string DataBase { get; set; } public string Table { get; set; } }
2、修改json檔案
在appsettings.json檔案中新增MongodbHost節點:
{ "Logging": { "LogLevel": { "Default": "Warning" } }, "option1": "value1_from_json", "option2": 2, "subsection": { "suboption1": "subvalue1_from_json" }, "student": [ { "Name": "Gandalf", "Age": "1000" }, { "Name": "Harry", "Age": "17" } ], "AllowedHosts": "*", //MongoDb "MongodbHost": { "Connection": "mongodb://127.0.0.1:27017", "DataBase": "TemplateDb", "Table": "CDATemplateInfo" } }
注意:
MongodbHost裡面的屬性名必須要和定義的實體類裡面的屬性名稱一致。
3、在StartUp類裡面配置
新增OptionConfigure方法繫結
private void OptionConfigure(IServiceCollection services) { //MongodbHost資訊 services.Configure<MongodbHostOptions>(Configuration.GetSection("MongodbHost")); }
在ConfigureServices方法中呼叫上面定義的方法:
public void ConfigureServices(IServiceCollection services) { // 呼叫OptionConfigure方法 OptionConfigure(services); services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1); }
在控制器中使用,程式碼如下:
using System; using System.Collections.Generic; using System.Linq; using System.Threading.Tasks; using Microsoft.AspNetCore.Http; using Microsoft.AspNetCore.Mvc; using Microsoft.Extensions.Options; namespace ReadJsonDemo.Controllers { [Route("api/[controller]")] [ApiController] public class MongodbController : ControllerBase { private readonly MongodbHostOptions _mongodbHostOptions; /// <summary> /// 通過建構函式注入 /// </summary> /// <param name="mongodbHostOptions"></param> public MongodbController(IOptions<MongodbHostOptions> mongodbHostOptions) { _mongodbHostOptions = mongodbHostOptions.Value; } [HttpGet] public async Task Get() { await Response.WriteAsync("Connection:" + _mongodbHostOptions.Connection + "\r\nDataBase;" + _mongodbHostOptions.DataBase + "\r\nTable:" + _mongodbHostOptions.Table); } } }
執行結果:
3、讀取自定義json檔案
在上面的例子中都是讀取的系統自帶的appsettings.json檔案,那麼該如何讀取我們自己定義的json檔案呢?這裡可以使用ConfigurationBuilder類。
例項化類
var builder = new ConfigurationBuilder();
新增方式1
builder.AddJsonFile("path", false, true);
其中path表示json檔案的路徑,包括路徑和檔名。
新增方式2
builder.Add(new JsonConfigurationSource {Path= "custom.json",Optional=false,ReloadOnChange=true }).Build()
具體程式碼如下:
private void CustomOptionConfigure(IServiceCollection services) { IConfiguration _configuration; var builder = new ConfigurationBuilder(); // 方式1 //_configuration = builder.AddJsonFile("custom.json", false, true).Build(); // 方式2 _configuration = builder.Add(new JsonConfigurationSource {Path= "custom.json",Optional=false,ReloadOnChange=true }).Build(); services.Configure<WebSiteOptions>(_configuration.GetSection("WebSiteConfig")); }
ConfigureServices方法如下:
public void ConfigureServices(IServiceCollection services) { // 呼叫OptionConfigure方法 OptionConfigure(services); CustomOptionConfigure(services); services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_1); }
控制器程式碼如下:
using System; using System.Collections.Generic; using System.Linq; using System.Threading.Tasks; using Microsoft.AspNetCore.Http; using Microsoft.AspNetCore.Mvc; using Microsoft.Extensions.Options; namespace ReadJsonDemo.Controllers { [Route("api/[controller]")] [ApiController] public class MongodbController : ControllerBase { private readonly MongodbHostOptions _mongodbHostOptions; private readonly WebSiteOptions _webSiteOptions; /// <summary> /// 通過建構函式注入 /// </summary> /// <param name="mongodbHostOptions"></param> public MongodbController(IOptions<MongodbHostOptions> mongodbHostOptions,IOptions<WebSiteOptions> webSiteOptions) { _mongodbHostOptions = mongodbHostOptions.Value; _webSiteOptions = webSiteOptions.Value; } [HttpGet] public async Task Get() { await Response.WriteAsync("Connection:" + _mongodbHostOptions.Connection + "\r\nDataBase;" + _mongodbHostOptions.DataBase + "\r\nTable:" + _mongodbHostOptions.Table); await Response.WriteAsync("\r\n"); await Response.WriteAsync("WebSiteName:" + _webSiteOptions.WebSiteName + "\r\nWebSiteUrl;" + _webSiteOptions.WebSiteUrl); } } }
二、在類庫中讀取json檔案
在上面的示例中都是直接在應用程式中讀取的,那麼如何在單獨的類庫中讀取json檔案呢?看下面的示例程式碼:
using Microsoft.Extensions.Configuration; using Microsoft.Extensions.DependencyInjection; using Microsoft.Extensions.Options; using System; using System.Collections.Generic; using System.IO; using System.Text; namespace Common { public class JsonConfigHelper { public static T GetAppSettings<T>(string fileName, string key) where T : class, new() { // 獲取bin目錄路徑 var directory = AppContext.BaseDirectory; directory = directory.Replace("\\", "/"); var filePath = $"{directory}/{fileName}"; if (!File.Exists(filePath)) { var length = directory.IndexOf("/bin"); filePath = $"{directory.Substring(0, length)}/{fileName}"; } IConfiguration configuration; var builder = new ConfigurationBuilder(); builder.AddJsonFile(filePath, false, true); configuration = builder.Build(); var appconfig = new ServiceCollection() .AddOptions() .Configure<T>(configuration.GetSection(key)) .BuildServiceProvider() .GetService<IOptions<T>>() .Value; return appconfig; } } }
注意:這裡要新增如下幾個程式集,並且要注意新增的程式集的版本要和.net core web專案裡面的程式集版本一致,否則會報版本衝突的錯誤
1、Microsoft.Extensions.Configuration
2、Microsoft.Extensions.configuration.json
3、Microsoft.Extensions.Options
4、Microsoft.Extensions.Options.ConfigurationExtensions
5、Microsoft.Extensions.Options
json檔案如下:
{ "WebSiteConfig": { "WebSiteName": "CustomWebSite", "WebSiteUrl": "https:localhost:12345" }, "DbConfig": { "DataSource": "127.0.0.1", "InitialCatalog": "MyDb", "UserId": "sa", "Password": "123456" } }
DbHostOptions實體類定義如下:
using System; using System.Collections.Generic; using System.Linq; using System.Threading.Tasks; namespace ReadJsonDemo { public class DbHostOptions { public string DataSource { get; set; } public string InitialCatalog { get; set; } public string UserId { get; set; } public string Password { get; set; } } }
注意:這裡的DbHostOptions實體類應該建在單獨的類庫中,這裡為了演示方便直接建在應用程式中了。
在控制器中呼叫:
using System; using System.Collections.Generic; using System.Linq; using System.Threading.Tasks; using Common; using Microsoft.AspNetCore.Http; using Microsoft.AspNetCore.Mvc; using Microsoft.Extensions.Options; namespace ReadJsonDemo.Controllers { [Route("api/[controller]")] [ApiController] public class MongodbController : ControllerBase { private readonly MongodbHostOptions _mongodbHostOptions; private readonly WebSiteOptions _webSiteOptions; /// <summary> /// 通過建構函式注入 /// </summary> /// <param name="mongodbHostOptions"></param> public MongodbController(IOptions<MongodbHostOptions> mongodbHostOptions,IOptions<WebSiteOptions> webSiteOptions) { _mongodbHostOptions = mongodbHostOptions.Value; _webSiteOptions = webSiteOptions.Value; } [HttpGet] public async Task Get() { DbHostOptions dbOptions = JsonConfigHelper.GetAppSettings<DbHostOptions>("custom.json", "DbConfig"); await Response.WriteAsync("DataSource:" + dbOptions.DataSource + "\r\nInitialCatalog;" + dbOptions.InitialCatalog+ "\r\nUserId:"+dbOptions.UserId+ "\r\nPassword"+dbOptions.Password); await Response.WriteAsync("\r\n"); await Response.WriteAsync("Connection:" + _mongodbHostOptions.Connection + "\r\nDataBase;" + _mongodbHostOptions.DataBase + "\r\nTable:" + _mongodbHostOptions.Table); await Response.WriteAsync("\r\n"); await Response.WriteAsync("WebSiteName:" + _webSiteOptions.WebSiteName + "\r\nWebSiteUrl;" + _webSiteOptions.WebSiteUrl); } } }
執行結果: