英文:
.Net 6.0. Dependency Injection. How do I inject by type?
问题
ICombiService接口有多个实现。我想根据appsettings.json中的字符串值来注入其中一个实现。可以通过以下方式找到配置的类型：
private static Type? GetConfiguredCombiServiceType(Settings settings){var type = typeof(ICombiService);var cst = AppDomain.CurrentDomain.GetAssemblies().SelectMany(s => s.GetTypes()).FirstOrDefault(p => !p.IsInterface && type.IsAssignableFrom(p)&& p.Name.Contains(settings.CombiSpecification));return cst;}
然后，如何注入配置的类型？我已经进行了广泛的搜索，但似乎找不到相关信息。我希望最终实现类似以下的代码：
var builder = new ServiceCollection()// 其他依赖项在这里 . . ..AddTransient<ICombiService>(cs => (ICombiService)combiService).BuildServiceProvider();
但这是一个多余的类型转换，不起作用。这种事情在AutoFac和Ninject中很容易实现，但我似乎找不到有关Microsoft DI实现的任何信息。非常感谢任何帮助。
英文:
I have multiple implementations of an ICombiService interface. I want to inject one of these implementations based on a string value from appsettings.json. I can find the configured type thus
private static Type? GetConfiguredCombiServiceType(Settings settings){var type = typeof(ICombiService);var cst = AppDomain.CurrentDomain.GetAssemblies().SelectMany(s => s.GetTypes()).FirstOrDefault(p => !p.IsInterface && type.IsAssignableFrom(p)&& p.Name.Contains(settings.CombiSpecification));return cst;}
How do I then inject this configured type? I have searched extensively, (maybe I'm wording my search wrong) but not finding anything. I want to end up with something like the following
var builder = new ServiceCollection()// Other dependencies here . . ..AddTransient<ICombiService>(cs => (ICombiService)combiService).BuildServiceProvider();
but that's a spurious cast and does not work. This kind of thing is easy enough with AutoFac and Ninject but I can't seem to find any info on Microsofts implementation of DI. Any help greatly appreciated.
答案1
得分: 1
I'm embarrassed to say, the answer is as simple asvar combiService = GetConfiguredCombiServiceType(settings);then in your builder...var builder = new ServiceCollection().AddTransient(typeof(ICombiService), combiService).BuildServiceProvider();
英文:
I'm embarrassed to say, the answer is as simple as
var combiService = GetConfiguredCombiServiceType(settings);
then in your builder...
var builder = new ServiceCollection().AddTransient(typeof(ICombiService), combiService).BuildServiceProvider();
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