相关疑难解决方法(0)

我有一个场景,我想使用方法组语法而不是匿名方法(或lambda语法)来调用函数.

该函数有两个重载,一个需要一个Action,另一个需要一个Func<string>.

我可以愉快地使用匿名方法(或lambda语法)调用两个重载,但如果我使用方法组语法,则会获得Ambiguous调用的编译器错误.我可以明确的解决方法铸造到Action或Func<string>,但不认为这应该是必要的.

任何人都可以解释为什么应该要求显式演员表.

代码示例如下.

class Program
{
    static void Main(string[] args)
    {
        ClassWithSimpleMethods classWithSimpleMethods = new ClassWithSimpleMethods();
        ClassWithDelegateMethods classWithDelegateMethods = new ClassWithDelegateMethods();

        // These both compile (lambda syntax)
        classWithDelegateMethods.Method(() => classWithSimpleMethods.GetString());
        classWithDelegateMethods.Method(() => classWithSimpleMethods.DoNothing());

        // These also compile (method group with explicit cast)
        classWithDelegateMethods.Method((Func<string>)classWithSimpleMethods.GetString);
        classWithDelegateMethods.Method((Action)classWithSimpleMethods.DoNothing);

        // These both error with "Ambiguous invocation" (method group)
        classWithDelegateMethods.Method(classWithSimpleMethods.GetString);
        classWithDelegateMethods.Method(classWithSimpleMethods.DoNothing);
    }
}

class ClassWithDelegateMethods
{
    public void Method(Func<string> func) { /* do something …

我有一个叫做接受的课Test,另一个接受.请参阅以下代码段.constructorAction<T>Func<T,T>

public class Test<T>
{
    //constructors
    public Test() { }
    public Test(Action<T> action) { }
    public Test(Func<T, T> action) { }

    //methods with same signature of constructor
    public void MyMethod1(Action<T> action) { }
    public void MyMethod2(Func<T, T> action) { }
}


public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        Test<string> t1 = new Test<string>(this.MyMethod1);
        Test<string> t2 = new Test<string>(this.MyMethod2);

        Test<string> t = new Test<string>();
        t.MyMethod1(MyMethod1);
        t.MyMethod2(MyMethod2);
    }

    public void MyMethod1(string value) { …