C#在运行时为Array.SetValue类型转换

Question

我正在尝试使用反射创建一个数组,并将值插入其中.我正在尝试为许多不同类型执行此操作,因此需要一个createAndFillArray能够执行此操作的函数:

String propertyName1 = "prop1";
String propertyName2 = "prop2";

Type t1 = typeof(myType).getProperty(propertyName1).PropertyType.getElementType();
Type t2 = typeof(myType).getProperty(propertyName2).PropertyType.getElementType();

double exampleA = 22.5;
int exampleB = 43;

Array arrA = createAndFillArray(t1, exampleA);
Array arrB = createAndFillArray(t2, exampleB);

private Array createAndFillArray(Type t, object val){
    Array arr = Array.CreateInstance( t, 1); //length 1 in this example only, real-world is of variable length.
    arr.SetValue( val, 0 ); //this causes the following error: "System.InvalidCastException : Object cannot be stored in an array of this type."
    return arr;
}

A级如下:

public class A{
    public A(){}

    private double val;
    public double Value{
        get{ return val; }
        set{ this.val = value; }
    }

    public static implicit operator A(double d){
        A a = new A();
        a.Value = d;
        return a;
    }
}

和B类非常相似,但有int:

public class B{
    public B(){}

    private double val;
    public double Value{
        get{ return val; }
        set{ this.val = value; }
    }

    public static implicit operator B(double d){
        B b = new B();
        b.Value = d;
        return b;
    }
}

和myType类似如下:

public class myType{
    public A prop1{ get; set; }
    public B prop2{ get; set; }
}

我希望隐式运算符可以确保将double转换为A类,或者将int转换为B类,并避免错误; 但这显然不是这样.

以上内容用于自定义反序列化类,该类从自定义数据格式获取数据并填充相应的.Net对象属性.我是通过反射和运行时这样做的,所以我认为两者都是不可避免的.我的目标是C#2.0框架.

我有几十个,甚至几百个类似于A和的类B,所以我更愿意找到一个改进createAndFillArray方法的解决方案而不是改变这些类的解决方案.

Answer 1

下面是一个使用反射来查找转换方法的示例。因此，如果您可以在您的类型上获取该方法并自行进行转换。

复制自：http ://bytes.com/topic/c-sharp/answers/903775-getting-operators-using-reflection

//EndType is the type I want to PRODUCE
//StartType is the type I am pulling data FROM
MethodInfo mi = EndType.GetMethod(
    "op_Implicit", 
    (BindingFlags.Public | BindingFlags.Static), 
    null, 
    new Type[] { StartType }, 
    new ParameterModifier[0]
);
//Now if mi is NOT null, it means there is an operator that allows for converting StartType to EndType, if it is null, there isn't one