Question

我在vnext项目中实现了一个Custom ViewLocationExpander。我想从ViewLocationExpander中的appsettings.json文件中读取应用程序设置值，因此IOptions＆lt;＆gt;已经注入到自定义ViewLocationExpander的构造函数中。但是，在将自定义ViewLocationExpander添加到RazorViewEngine选项时，需要ViewLocationExpander的对象，由于依赖性，无法创建该对象。

以下是代码

public MyViewLocationExpander(IOptions<MyAppSettings> MyAppSettings) 
{
  var appSettings = MyAppSettings.Value;
  client = appSettings.Client // client is a private field and is used in ExpandViewLocations function
}

MyAppSettings.cs如下：

public class MyAppSettings
{
  public string Client { get; set; }
}

在Startup.cs ConfigureServices方法

中

services.Configure<RazorViewEngineOptions>(config =>
{
  //config.ViewLocationExpanders.Add(new MyViewLocationExpander());
  // MyViewLocationExpander cannot be created as it has a dependency on IOptions<MyAppSettings>
});

有关如何将自定义ViewLocationExpander添加到RazorViewEngineOptions的任何帮助都会很棒。

Answer 1

从容器中解析服务的一种方法是在ExpandViewsMethod中解析它们

using Microsoft.Extensions.DependencyInjection;

public IEnumerable<string> ExpandViewLocations(ViewLocationExpanderContext context, IEnumerable<string> viewLocations)
{
    var service = context.ActionContext.HttpContext.RequestServices.GetService<IService>();
}

在View Location Expander中注入依赖关系

1 个答案: