为什么将带有params object []的方法作为args引发转换错误？

Question

I am trying to wrap my soap-calls with a generic wrapper to simplify logging and other commons.

When trying to invoke a method on the client I send in, I get this error thrown when using parameters:

{"Unable to cast object of type 'System.String' to type 'System.String[]'."}

My code:

private T CallExternalSoap<T>(object client, string funcName, params object[] args)
{
    var type = client.GetType();

    var method = type.GetMethod(funcName);

    if (method is null)
    {
        throw new NullReferenceException($"Could not find method {funcName} on object of type {type}.");
    }

    if (method.GetParameters().Length != args.Length)
    {
        throw new Exception($"Number of parameters in {args} does not match number of expected parameters in method {funcName} . Expected {method.GetParameters().Length} parameters");
    }

    var result = (T)method.Invoke(client, args);
    return result;
}

No matter which objects/params I send in I get that error. Any ideas?

Answer 1

The issue is not with the parameters but with casting the result.

The SOAP method is returning a string but you are casting as a string[] based on the type parameter.

CallExternalSoap<string[]>(...