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希望在C#中使用静态抽象函数。有什么解决办法吗?

oop c#

FallenAvatar · 技术社区 · 16 年前

这是我的情况。我正在C#中使用WMI。谢天谢地,我发现 MgmtClassGen.exe

但是,我一直在浏览自动生成的类,并将公共代码剥离为实用程序类或基类。到目前为止还不错,清理了很多代码。但我遇到了困难。每个类都有几个(大约8个)静态函数 GetInstances . 基本上有两个重载,另一个函数只是提供默认参数。

我想把这些函数放在基类中,因为它们在所有类中都是相同的,除了3个变量。即 ClassName (比如说) MicrosoftDNS_Zone Namespace root\microsoftdns )和 ManagementScope 对象

我现在所做的就是这样;将包含代码的2个函数移到基类中,并为上面列出的3个差异添加了3个参数。但这仍然需要在每个类中包含8个函数,这些函数只使用 命名空间 Scope

有没有办法重构这个每个派生类中的“包装器”?
我可以声明静态吗不知怎的从…那里得到了类名等派生类?
反思在这里能起作用吗?

基类:

namespace WMI
{
    public abstract class Object : System.ComponentModel.Component
    {
        // ...
        protected static WMI.ManagementTypeCollection GetInstances( string className, string namespaceName, ManagementScope statMgmtScope, ManagementScope mgmtScope, EnumerationOptions enumOptions, Func<ManagementObject,WMI.Object> del )
        {
            if( (mgmtScope == null) )
            {
                if( (statMgmtScope == null) )
                {
                    mgmtScope = new System.Management.ManagementScope();
                    mgmtScope.Path.NamespacePath = namespaceName;
                }
                else
                {
                    mgmtScope = statMgmtScope;
                }
            }
            System.Management.ManagementPath pathObj = new System.Management.ManagementPath();
            pathObj.ClassName = className;
            pathObj.NamespacePath = namespaceName;
            System.Management.ManagementClass clsObject = new System.Management.ManagementClass( mgmtScope, pathObj, null );
            if( (enumOptions == null) )
            {
                enumOptions = new System.Management.EnumerationOptions();
                enumOptions.EnsureLocatable = true;
            }
            return new WMI.ManagementTypeCollection( clsObject.GetInstances( enumOptions ), del );
        }

        protected static WMI.ManagementTypeCollection GetInstances( string className, string namespaceName, ManagementScope statMgmtScope, ManagementScope mgmtScope, string condition, String[] selectedProperties, Func<ManagementObject, WMI.Object> del )
        {
            if( (mgmtScope == null) )
            {
                if( (statMgmtScope == null) )
                {
                    mgmtScope = new System.Management.ManagementScope();
                    mgmtScope.Path.NamespacePath = namespaceName;
                }
                else
                {
                    mgmtScope = statMgmtScope;
                }
            }
            System.Management.ManagementObjectSearcher ObjectSearcher = new System.Management.ManagementObjectSearcher( mgmtScope, new SelectQuery( className, condition, selectedProperties ) );
            System.Management.EnumerationOptions enumOptions = new System.Management.EnumerationOptions();
            enumOptions.EnsureLocatable = true;
            ObjectSearcher.Options = enumOptions;
            return new WMI.ManagementTypeCollection( ObjectSearcher.Get(), del );
        }
    }
}

namespace WMI.MicrosoftDNS
{
    public class AAAAType : WMI.Object
    {
        private static string CreatedWmiNamespace = "root\\microsoftdns";
        private static string CreatedClassName = "MicrosoftDNS_AAAAType";
        private static System.Management.ManagementScope statMgmtScope = null;

        // ...

        public static WMI.ManagementTypeCollection GetInstances()
        {
            return GetInstances( null, null, null );
        }

        public static WMI.ManagementTypeCollection GetInstances( string condition )
        {
            return GetInstances( null, condition, null );
        }

        public static WMI.ManagementTypeCollection GetInstances( System.String[] selectedProperties )
        {
            return GetInstances( null, null, selectedProperties );
        }

        public static WMI.ManagementTypeCollection GetInstances( string condition, System.String[] selectedProperties )
        {
            return GetInstances( null, condition, selectedProperties );
        }

        public static WMI.ManagementTypeCollection GetInstances( ManagementScope mgmtScope, EnumerationOptions enumOptions )
        {
            return WMI.Object.GetInstances( CreatedClassName, CreatedWmiNamespace, statMgmtScope, mgmtScope, enumOptions, mo => new AAAAType( mo ) );
        }

        public static WMI.ManagementTypeCollection GetInstances( ManagementScope mgmtScope, string condition )
        {
            return GetInstances( mgmtScope, condition, null );
        }

        public static WMI.ManagementTypeCollection GetInstances( ManagementScope mgmtScope, System.String[] selectedProperties )
        {
            return GetInstances( mgmtScope, null, selectedProperties );
        }

        public static WMI.ManagementTypeCollection GetInstances( ManagementScope mgmtScope, string condition, System.String[] selectedProperties )
        {
            return WMI.Object.GetInstances( CreatedClassName, CreatedWmiNamespace, statMgmtScope, mgmtScope, condition, selectedProperties, mo => new AAAAType( mo ) );
        }
    }
}

3 回复 | 直到 16 年前

LBushkin 16 年前

下面是我的意思的一个例子:

public class WMIInstance
{
    private readonly string CreatedWmiNamespace = "root\\microsoftdns";
    private readonly string CreatedClassName = "MicrosoftDNS_AAAAType";
    private readonly System.Management.ManagementScope statMgmtScope = null;

    public WMIInstance( string namespace, string className, ManagementScope scope )
    { /*... initialize private members here... */

    public WMI.ManagementTypeCollection GetInstances( System.String[] selectedProperties )
    { return WMI.Object.GetInstances( ... ); }

    /* other overloads ... */
}

public class AAAAType : WMI.Object
{
    private static string CreatedWmiNamespace = "root\\microsoftdns";
    private static string CreatedClassName = "MicrosoftDNS_AAAAType";
    private static System.Management.ManagementScope statMgmtScope = null;

    private static readonly WMIInstances _instances = new WMIInstance( CreatedWmiNamespace, CreatedClassName, statMgmgtScope );

    public static WMIInstances Getter { get { return _instances; } }
}

tbreffni 16 年前

optional arguments 方法的默认值,这在很多情况下消除了多个重载的需要。例如:

public void ExampleMethod(int required, string optionalstr = "default string", int optionalint = 10)

您可以使用 ExampleMethod(1) 或 ExampleMethod(1, 'Test', 9)

user76035 16 年前

也许是个小工厂?

class Config { string ClassName; string Namespace; ManagementScope Scope; }

static class Factory {
     public static readonly Dictionary<Type, Config> Configs = new ...;

     static GetInstances(Type requestedType, ...) {
         var config = Configs[requestedType];
         // work with it...
     }
}

class AAAAType {
     static AAAAType{
          Factory.Configs.Add(typeof(AAAAType), new Config{ ... });
     }
}

静电过多
一个方法的6个参数,包括一个函数指针真的吗?
在顶部使用两个有助于避免限定名
获得代码的意图并不容易