未找到 String 的构造函数

Question

如果我在包含List<string[]> 或Dictionary<string,string[]>（使用GenericDictionaryEditor）的属性网格中有一个对象，当我单击属性旁边的详细信息并单击添加时，会弹出一条消息说没有构造函数可以找到（对于列表）或找不到无参数构造函数（对于字典）。我真的不懂编辑器或属性网格，如果有任何帮助，我们将不胜感激。

[DataMember(Name="FolderPaths")]
[ReadOnly(false)]
[Description("List of folder paths")]
[Editor(typeof(Wexman.Design.GenericDictionaryEditor<string, string[]>), typeof(UITypeEditor))]
[Wexman.Design.GenericDictionaryEditor(Title="Folder Paths")]
public Dictionary<string, string[]> FolderPaths { get; set; }

这个说没有为 System.string[] 找到构造函数。

[DataMember(Name="FolderPaths")]
[ReadOnly(false)]
[Description("List of folder paths")]
public List<string[]> FolderPaths { get; set; }

Answer 1

一种解决方案是为string[] 类型注册一个TypeDescriptionProvider。这是示例代码（您需要在程序开始时注册它，然后再显示任何属性网格）：

...
TypeDescriptor.AddProvider(new StringArrayDescriptionProvider(), typeof(string[]));
...

这里是StringArrayDescriptionProvider 代码：

public class StringArrayDescriptionProvider : TypeDescriptionProvider
{
    private static TypeDescriptionProvider _baseProvider;

    static StringArrayDescriptionProvider()
    {
       // get default metadata
        _baseProvider = TypeDescriptor.GetProvider(typeof(string[]));
    }

    public override object CreateInstance(IServiceProvider provider, Type objectType, Type[] argTypes, object[] args)
    {
        // this is were we define create the instance
        // NB: .NET could do this IMHO...
        return Array.CreateInstance(typeof(string), 0);
    }

    public override IDictionary GetCache(object instance)
    {
        return _baseProvider.GetCache(instance);
    }

    public override ICustomTypeDescriptor GetExtendedTypeDescriptor(object instance)
    {
        return _baseProvider.GetExtendedTypeDescriptor(instance);
    }

    public override string GetFullComponentName(object component)
    {
        return _baseProvider.GetFullComponentName(component);
    }

    public override Type GetReflectionType(Type objectType, object instance)
    {
        return _baseProvider.GetReflectionType(objectType, instance);
    }

    public override Type GetRuntimeType(Type reflectionType)
    {
        return _baseProvider.GetRuntimeType(reflectionType);
    }

    public override ICustomTypeDescriptor GetTypeDescriptor(Type objectType, object instance)
    {
        return _baseProvider.GetTypeDescriptor(objectType, instance);
    }

    public override bool IsSupportedType(Type type)
    {
        return _baseProvider.IsSupportedType(type);
    }
}

这是它的外观：