是否可以创建 typeof(T).getElementOf() 类型的数组，并在通用方法中对其进行初始化<t> ?</t>

Question

I have a generic method, and wish to create an instance of the type T in question after verifying that it is an array:

public static T Ins<T>(string s, int delim) {
    if (typeof(T).IsArray) {

        char d = d_order[delim];
        string[] part = s.Split(d);
        Array temp = Array.CreateInstance(typeof(T).GetElementType(), part.Length);
        T tot = (T)temp; // doesn't work (can't convert from array to T)
    
        var genMethod = typeof(InputFunctions).GetMethod("Ins").MakeGenericMethod(typeof(T).GetElementType());

        //Calling genMethod on substrings of s to create the elements
    }
    else {
        //defining the function for non array types
    }

InputFunctions is the current class, and d_order is a character array defined elsewhere.

The idea is to perform recursion to initialize this. For example, if T is int[][][], and s is the string parameter, I want to create an instance of int[s.Split(d).Length][][] and then fill it with this function called on int[][] and so on.

The above didn't work due to a casting error. I have another attempt below:

replace the array declaration with:

object[] temp = new object[part.Length]

and putting the cast to T after filling in the elements with recursion.

The problem with this is that object[] is not convertible to T so even though I know that every element in the array is of the proper type, I can't convert it to T. If there is a way around that, that would also solve my problem. Thank you for your help.

Answer 1

You can cast temp to T like Guru Stron has shown, but that doesn't allow you to use the resulting T like an array. If you want to use it as an array, you should not cast temp to T and keep using temp instead, because temp is of type Array . You can do just about everything you can do on "normal" arrays like int[] or string[] on an Array , except you lose some type safety. But you are using reflection here, so no type safety in the first place.

To set the index i of temp to something , just do:

temp.SetValue(something, i);

You should cast temp to T before returning, of course:

return (T)(object)temp;

Here is an example of how you'd write this method with a constant length:

public static T Ins<T>() {
    const int length = 10;
    if (typeof(T).IsArray) {
        Array temp = Array.CreateInstance(typeof(T).GetElementType(), length);

        var genMethod = typeof(InputFunctions).GetMethod("Ins").MakeGenericMethod(typeof(T).GetElementType());
        for (int i = 0 ; i < length ; i++) {
            temp.SetValue(genMethod.Invoke(null, null), i);
        }
        return (T)(object)temp;
    }
    else {
        return default(T);
    }
}

Answer 2

Try casting temp to object first and then to T :

T tot = (T)(object)temp;