我的arraylist和数组问题? [英] My arraylist and array problem?

问题描述

我想在arraylist中添加许多int[,]数组，但是我无法以int[,]数据类型提取它们.
这段代码将演示我想做什么:

I want to add many int[,] arrays in an arraylist but I couldn''t extract them in int[,] data type.
This code will demonstrate what i want to do:

arraylist Myarraylist =new arraylist();
int [,] array1 = new int[3,2];
int [,] array2 = new int[5,2];
int [,] array3 = new int[6,4];

Myarraylist.add(array1);
Myarraylist.add(array2);
Myarraylist.add(array3);

我希望这个半代码能够发生:

I want this semi-code to happen:

int[,] Myarray1 = Myarraylist[1]

但是当我提取它们时，出现了一个问题，它们甚至不是object[,]
但只是object.如何将它们再次投射到int[,]?

谢谢您的帮助.

but when i extracted them a problem came up that they are objects not even object[,]
but just object. How can I cast them to int[,] again?

Thank you for your help.

推荐答案

您需要转换已取消引用的元素，例如，以下代码将起作用:

You need to cast the dereferenced element, for instance, the following code will work:

ArrayList Myarraylist = new ArrayList();
    int [,] array1 = new int[3,2];
    int [,] array2 = new int[5,2];
    int [,] array3 = new int[6,4];


    Myarraylist.Add(array1);
    Myarraylist.Add(array2);
    Myarraylist.Add(array3);

    // HERE the needed cast
    int[,] Myarray1 = (int[,])Myarraylist[1];

    for (int n = 0; n < 2; n++)
        Console.WriteLine("MyArray1[0,{0}]={1}", n, Myarray1[0, n]);

BTW作为以下注释(来自 MSDN [

BTW as the following note (from MSDN[^]) says

>以2.0版及更高版本的.NET Framework为目标的应用程序应使用System.Collections.Generic命名空间中的通用集合类，与非一般同类产品相比，它们提供了更高的类型安全性和效率.

Applications that target version 2.0 and later of the .NET Framework should use the generic collection classes in the System.Collections.Generic namespace, which provide greater type-safety and efficiency than their non-generic counterparts.

我强烈建议您使用通用容器而不是ArrayList.

I strongly suggest you using generic containers instead of ArrayList.

请勿使用ArrayList；当v.2.0中引入泛型时，它已过时.使用System.Collections.Generic.List.在您的情况下，请使用System.Collections.Generic.List<System.Collections.Generic.List<int>>.

它将代表锯齿状数组.使用System.Collections.Generic.List.ToArray获取等级1的数组.该元素将是列表，将每个与ToArray一起使用以获取嵌套的数组元素.

—SA

Don''t use the ArrayList; it was rendered obsolete when generics were introduced in v.2.0. Use System.Collections.Generic.List. In your case, use System.Collections.Generic.List<System.Collections.Generic.List<int>>.

It will represent jagged array. Use System.Collections.Generic.List.ToArray to get an array of rank 1. The element will be lists, use each one with ToArray to get nested array elements.

—SA

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