My Web API is using other project for one controller. Service works fine. But I am struggling to inject connection string from main Web API project into controller in external project.
How could this be achieved?
public class MyExternalController : Controller
{
private string _connStr;
public MyExternalController(string connStr)
{
_connStr = connStr;
}
// actions here
}
As others said in the comments, for something like a controller, you should be injecting something concrete like a DbContext, not a connection string. However, for future reference your issue here is injecting a string. There's no way to register something in the DI container to satisfy a dependency like that. Instead, you should inject your configuration or a strongly-typed configuration class.
Injecting IConfigurationRoot is a bit of an anti-pattern, but for something like a connection string, it's fine:
public MyExternalController(IConfigurationRoot config)
{
_connStr = config.GetConnectionString("MyConnectionString");
}
For everything else, though, you should use strongly-typed configuration classes.
public class FooConfig
{
public string Bar { get; set; }
}
Then, in ConfigureServices:
services.Configure<FooConfig>(Configuration.GetSection("Foo"));
Which of course would correspond with some bit of config like:
{
"Foo": {
"Bar": "Baz"
}
}
Then, in your controller, for example:
public MyExternalController(IOptionsSnapshot<FooConfig> fooConfig)
{
_fooConfig = fooConfig.Value;
}
DbContextinstead.