c# - 是否可以将委托(delegate)作为属性参数？

Question

是否可以将委托(delegate)作为属性的参数？

像这样:

public delegate IPropertySet ConnectionPropertiesDelegate();

public static class TestDelegate
{
    public static IPropertySet GetConnection()
    {
        return new PropertySetClass();
    }
}

[AttributeUsage(AttributeTargets.Class | AttributeTargets.Interface,AllowMultiple=false,Inherited=true)]
public class WorkspaceAttribute : Attribute
{
    public ConnectionPropertiesDelegate ConnectionDelegate { get; set; }

    public WorkspaceAttribute(ConnectionPropertiesDelegate connectionDelegate)
    {
        ConnectionDelegate = connectionDelegate;
    }
}

[Workspace(TestDelegate.GetConnection)]
public class Test
{
}

如果不可能，有哪些明智的选择？

Answer 1

不，您不能将委托(delegate)作为属性构造函数参数。查看可用类型:Attribute parameter types
作为一种解决方法(尽管它很笨拙且容易出错)，您可以创建一个 delegate with reflection :

[AttributeUsage(AttributeTargets.Class | AttributeTargets.Interface, AllowMultiple = false, Inherited = true)]
public class WorkspaceAttribute : Attribute
{
    public ConnectionPropertiesDelegate ConnectionDelegate { get; set; }

    public WorkspaceAttribute(Type delegateType, string delegateName)
    {
         ConnectionDelegate = (ConnectionPropertiesDelegate)Delegate.CreateDelegate(typeof(ConnectionPropertiesDelegate), delegateType, delegateName);
    }
}

[Workspace(typeof(TestDelegate), "GetConnection")]
public class Test
{
}