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如何编写一个通用函数来调用具有特定类的通用函数?

delegates generics c#

Lior Bruder · 技术社区 · 7 年前

我的代码:

public class BaseParamsClass
{
    public BaseParamsClass(int pBaseParam = 0)
    {
        baseParam = pBaseParam;
    }

    public int baseParam;
}

public class Parent1ParamsClass : BaseParamsClass
{
    public Parent1ParamsClass(int pBaseParam = 0) : base(pBaseParam)
    {

    }

    public int parentParam1;
}

public class Parent2ParamsClass : BaseParamsClass
{
    public Parent2ParamsClass(int pBaseParam = 0) : base(pBaseParam)
    {

    }

    public int parentParam2;
}

public delegate void Parent1Callback(Parent1ParamsClass theParams);
public delegate void Parent2Callback(Parent2ParamsClass theParams);

private IEnumerator CoRFunction1(Parent1Callback parent1Callback)
{
    // This demonstrate few actions i do before the call
    yield return new WaitForSeconds(1);

    // Now i get the result, it can be 0-10, each one should activate different callback
    int result = 0;

    parent1Callback(new Parent1ParamsClass(0));
}

private IEnumerator CoRFunction2(Parent2Callback parent2Callback)
{
    // This demonstrate few actions i do before the call
    yield return new WaitForSeconds(1);

    // Now i get the result, it can be 0-10, each one should activate different callback
    int result = 0;

    // Need a generic way to do the next line:
    parent2Callback(new Parent2ParamsClass(0));
}

private IEnumerator CoRFunction2(Parent2Callback parent2Callback)
{
    // This demonstrate few actions i do before the call
    yield return new WaitForSeconds(1);

    // Now i get the result, it can be 0-10, each one should activate different callback
    int result = 0;

    // Need a generic way to do the next line:
    parent2Callback(new Parent2ParamsClass(0));
}

我需要的是替换“//需要a…”后面的行的方法在更一般的情况下,最后两个函数应该是这样的:

private IEnumerator CoRFunction1(Parent1Callback parent1Callback)
{
    // This demonstrate few actions i do before the call
    yield return new WaitForSeconds(1);

    // Now i get the result, it can be 0-10, each one should activate different callback
    int result = 0;

    genericFunction<Parent1Callback>(Parent1ParamsClass);
}

private IEnumerator CoRFunction2(Parent2Callback parent2Callback)
{
    // This demonstrate few actions i do before the call
    yield return new WaitForSeconds(1);

    // Now i get the result, it can be 0-10, each one should activate different callback
    int result = 0;

    genericFunction<Parent2Callback>(Parent2ParamsClass);
}

如何创建“genericFunction”有什么想法吗?

2 回复 | 直到 7 年前

GPW 7 年前

我评论道-现在还不太清楚你到底想要实现什么,我怀疑你可以用一种比你想要的更好的方式来实现。。。但我要说的是认为下面这样的方法可能会奏效。

更改基参数类,使您不必依赖构造函数来设置其内部字段,然后将一些泛型方法仅约束为基类型,这样您最终会遇到这种情况:

public class BaseParamsClass
{
    public virtual void SetParam(int pBaseParam)
    {
        baseParam = 0;
    }

    public int baseParam;
}

public class Parent1ParamsClass : BaseParamsClass
{
    public override void SetParam(int pBaseParam)
    {
        base.SetParam(pBaseParam);
        //do other stuff specific to this class...
    }
    public int parentParam1;
}

public class Parent2ParamsClass : BaseParamsClass
{
    public override void SetParam(int pBaseParam)
    {
        base.SetParam(pBaseParam);
        //do other stuff specific to this class...
    }

    public int parentParam2;
}


public delegate void GenericCallback<T>(T theParams) where T : BaseParamsClass, new();

private IEnumerator GenericCorFunction<T>(GenericCallback<T> callback) where T:BaseParamsClass, new()
{
    // This demonstrate few actions i do before the call
    yield return new WaitForSeconds(1);

    // Now i get the result, it can be 0-10, each one should activate different callback
    int result = 0;

    //I assume you want result here.
    //Also note that you can't use the constructor to set the base param as at compile time
    //we're not sure which type will be being used.  There are ways around this but it's
    //probably clearer to use basic constructor then call the SetParam virtual/overridden method            
    var param = new T();
    param.SetParam(result);
    callback(param);
}

您可以这样使用它:

var newEnumerator = GenericCorFunction<Parent2ParamsClass>(p =>
{
    //this is the callback function body.  This will only run when 
    //called at the end of the GenericCorFunction
    //Do things with p, which will be a PArent2ParamsClass object
    //with its baseParam field set to whatever result was.
    if (p.baseParam == 3)
    {
        throw new NotImplementedException();
    }
});

//do stuff with newEnumerator...

Mong Zhu Bart de Boer 7 年前

另一种方法是 Activator.CreateInstance 。这将允许您绕过 new() 限制并使用已编写的构造函数:

public delegate void ParentCallback<T>(T theParams) where T : BaseParamsClass;

private void CoRFunction<T>(ParentCallback<T> parentCallback) where T : BaseParamsClass
{    
    // Now i get the result, it can be 0-10, each one should activate different callback
    int result = 0;

    parentCallback((T)Activator.CreateInstance(typeof(T), 11));
}

(我将其更改为无效,以使其可供我测试)

下面是测试代码和我用来测试它的调用:

public void Call_1(Parent1ParamsClass par1)
{
    Console.WriteLine("CALL 1 baseParam: " + par1.baseParam);
}

public void Call_2(Parent2ParamsClass par2)
{
    Console.WriteLine("CALL 2 baseParam: " + par2.baseParam);
}

电话:

CoRFunction<Parent1ParamsClass>(Call_1);
CoRFunction<Parent2ParamsClass>(Call_2);

输出:

调用1 baseParam:11
调用2 baseParam:11