我可以在ASP中进行必要的配置吗。净核心?

使用 PostConfigure<T> 带有一个回调,它将在每个 Configure<T> 被处决了。这将允许用户以任何顺序以任何方式配置选项,并允许您查看(未配置的)选项,并在需要时引发异常。

class FooBarOptions
{
    public string AString { get; set; }
}

services.PostConfigure<FooBarOptions>(options => {
    // ... validate configuration
    if (options.AString == null)
    {
        throw new InvalidProgramException($"{nameof(FooBarOptions)} is not configured properly");
    }
});

services.Configure<FooBarOptions>(Configuration.GetSection("FooBarOptions"));

工具书类

• https://docs.microsoft.com/en-us/aspnet/core/fundamentals/configuration/options?view=aspnetcore-5.0#options-post-configuration
• https://andrewlock.net/delaying-strongly-typed-options-configuration-using-postconfigure-in-asp-net-core/

如果您想让启动文件的“绑定”部分保持简洁,可以在 IConfiguration 或 IServiceCollection 会有用的。下面是一个基本的实现。

static class ConfigurationBindingExtensions
{
    public static void BindSection<T>(this IConfiguration configuration, IServiceCollection services, string sectionName) where T : class
    {
        var config = configuration.GetSection(sectionName);
        if (config.Exists())
        {
            services.Configure<T>(config);
        }
        else
        {
            throw new ConfigurationSectionNotFoundException(sectionName);
        }
    }
}

[Serializable]
class ConfigurationSectionNotFoundException : Exception, System.Runtime.Serialization.ISerializable
{
    public string SectionName { get; set; }

    public ConfigurationSectionNotFoundException(string sectionName)
        : this(sectionName, string.Format("Section {0} was not found in the configuration file", sectionName))
    {
        this.SectionName = sectionName;
    }

    public ConfigurationSectionNotFoundException(string sectionName, string message)
        : base(message)
    {
        this.SectionName = sectionName;
    }

    protected ConfigurationSectionNotFoundException(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context)
        : base(info, context)
    {
        if (info == null)
            throw new ArgumentNullException(nameof(info));

        SectionName = info.GetString("SectionName");
    }

    [System.Security.Permissions.SecurityPermission(System.Security.Permissions.SecurityAction.Demand, SerializationFormatter = true)]
    public override void GetObjectData(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context)
    {
        if (info == null)
            throw new ArgumentNullException(nameof(info));

        info.AddValue("SectionName", SectionName);

        base.GetObjectData(info, context);
    }

    [System.Security.Permissions.SecurityPermission(System.Security.Permissions.SecurityAction.LinkDemand, Flags = System.Security.Permissions.SecurityPermissionFlag.SerializationFormatter)]
    void System.Runtime.Serialization.ISerializable.GetObjectData(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context)
    {
        if (info == null)
            throw new ArgumentNullException(nameof(info));

        GetObjectData(info, context);
    }
}

你会这样称呼它:

Configuration.BindSection<FooBarOptions>(services, "FooBar");

如果未定义节,这将引发自定义异常——如果对您更有意义,您可以用其他内容替换它。可能是杀伤力太大了,但它能保持启动。漂亮整洁。

试试这个

var exist = Configuration.GetSection("FooBar").Exist();
if (exist) services.Configure<FooBarOptions>(Configuration.GetSection("FooBar"));
else ....throw exception