如何在blazor webassembly中访问appsettings

Question

我目前正在尝试将api网址保存在appsettings中。但是，configuration.Propertiers似乎是空的。我不确定如何获取设置。在program.cs中：

public static async Task Main(string[] args)
{
   var builder = WebAssemblyHostBuilder.CreateDefault(args);
   //string url = builder.Configuration.Properties["APIURL"].ToString();
   foreach (var prop in builder.Configuration.Properties)
      Console.WriteLine($"{prop.Key} : {prop.Value}" );
   //builder.Services.AddSingleton<Service>(new Service(url));
   builder.RootComponents.Add<App>("app");
   await builder.Build().RunAsync();
}

Answer 1

作为示例，我这样实现（客户端Blazor）：

appsettings.json：

{
    "api": "https://www.webapiurl.com/"
    "ForceHTTPS": false
}

然后，输入了配置类

 public class APISetting
    {

        public string api { get; set; }

        public bool ForceHTTPS { get; set; }

    }

然后，在启动时加载：

public class Startup
    {
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddSingleton(GetConfiguration());
        }
        public void Configure(IComponentsApplicationBuilder app )
        {
            app.AddComponent<App>("app");
        }

        public APISetting GetConfiguration()
        {
            using (var stream = System.Reflection.Assembly.GetExecutingAssembly().GetManifestResourceStream("appsettings.json"))
            using (var reader = new System.IO.StreamReader(stream))
            {
                return System.Text.Json.JsonSerializer.Deserialize<APISetting>(reader.ReadToEnd());
            }
        }
    }

Answer 2

我通过使用应用程序wwwroot文件夹中的settings.json文件存储解决了这个问题，并注册了一个任务来获取设置：

Progam.cs

public static async Task Main(string[] args)
{
    var builder = WebAssemblyHostBuilder.CreateDefault(args);

    builder.Services.AddSingleton(async p =>
    {
        var httpClient = p.GetRequiredService<HttpClient>();
        return await httpClient.GetJsonAsync<APISetting>("settings.json")
            .ConfigureAwait(false);
    });

SampleComponent.razor

@inject Task<Settings> getsettingsTask
@inject HttpClient client
...
@code {
    private async Task CallApi()
    {
        var response = await client.GetJsonAsync<SomeResult>(await getsettingsTask());
    }
}