c# - 动态将Func转换为对应的Action

Question

我尝试在函数和操作上使用 Convert 方法，这样我就可以避免编写接受 Func 类型委托(delegate)的重复方法。转换方法来自Convert Action<T> to Action<object>

public class Program
{
    static void Main(string[] args)
    {
        var program = new Program();
        var mi = program.GetType().GetMethod("Function", BindingFlags.Instance | BindingFlags.Public);
        // Can be any version of Func
        var funcType = typeof(Func<int, int>);
        // Create action delegate somehow instead
        var del = mi.CreateDelegate(funcType, null);
        // Or dynamically convert the Func to a corresponding Action type (in this case Action<int>)
    }

    // Or find a way to pass it in as a parameter here
    public Action<object> Convert<T>(Action<T> action)
    {
        return o => action((T)o);
    }

    public int Function(int five)
    {
        return five;
    }
}

Answer 1

我认为您正在寻找这样的东西:

public static Action<T1> IgnoreResult<T1,T2>(Func<T1,T2> func)
{
    return x => func(x);
}

但是对于 Func<T1,T2....> 的所有变体

我认为这会起作用:

public static Action<TR> IgnoreResult<TR>(Delegate f)
{
    return x => f.DynamicInvoke(x);
}

使用情况:

var action = IgnoreResult<int>(new Func<int,int>(program.Function));
action(5);

如果不复制并粘贴 Action<T1...> 的所有变体的第一个示例，您将无法让它推断参数和返回类型。和Func<T1,T2...> .