如何动态生成和填充多维数组 [英] How can I dynamically generate and populate a multi-dimensional array
问题描述
我正在研究序列化器,遇到了带有多维数组的真实墙。如果我使用 Activator.CreateInstance()
,它会创建一个一维数组,但它按以下方式使用时却无法正常工作:
I'm working on a serializer and have run into a real wall with multi-dimensional arrays. If I use Activator.CreateInstance()
it creates a one dimensional array just fine, but it fails to work when used as follows:
var indices = new[] { 2, 2 };
Type type = typeof(int[,]);
var result = Activator.CreateInstance(type, indices) as Array;
如果我改用 Array.CreateInstance()
生成我的数组,它适用于一维和多维数组。但是,我对数组上的 SetValue()
方法的所有调用(我用来动态设置值)都会产生一个异常,而它在单维数组上也能正常工作使用 Activator.CreateInstance()
创建。我真的在努力寻找可行的解决方案,以允许我动态创建任意尺寸/大小的数组,然后使用值填充该数组。我希望有更多反思
经验的人可以对此有所了解。
If I instead use Array.CreateInstance()
to generate my array, it works for single and multi-dimensional arrays alike. However, all my calls to the SetValue()
method on the array, which I use to dynamically set values, generates an exception, whereas it works fine on the single dimensional arrays I created using Activator.CreateInstance()
. I'm really struggling to find a viable solution that allows me to dynamically create an array of any dimension/size and then populate the array with values. I'm hoping someone with more reflection
experience can shed some light on this.
尝试创建多重带有Activator的三维数组我得到一个例外:
When trying to create a multi-dimensional array with Activator I get the exception:
找不到类型'System.Int32 [,]'的构造函数。
Constructor on type 'System.Int32[,]' not found.
当我改用Array.CreateInstance()然后调用SetValue()时,我从SetValue()调用中得到以下异常:
When I instead use Array.CreateInstance() and then call SetValue() I get the following exception from the SetValue() call:
对象不能存储在这种类型的数组中。
Object cannot be stored in an array of this type.
坦率地说,这对我来说毫无意义,因为该值是一个int值,而数组是一个int [,]。
Which frankly makes no sense to me since the value is an int and the array is an int[,].
我在我的项目中使用的是4.5框架我也用4.6重新创建了这个问题。
I am using the 4.5 framework for my project though I recreated the problem with 4.6 as well.
推荐答案
您可以调用 Array.CreateInstance
具有实际的 ElementType
,在这种情况下为 int
。
You can call Array.CreateInstance
with the actual ElementType
which is int
in this case.
var indices = new[] { 2, 3 };
var arr = Array.CreateInstance(typeof(int), indices);
然后可以用 SetValue
填充数组没有任何例外。例如,
Then you can populate the array with SetValue
without any exception. For example
var value = 1;
for (int i = 0; i < indices[0]; i++)
{
for (int j = 0; j < indices[1]; j++)
{
arr.SetValue(value++, new[] { i, j });
}
}
//arr = [ [ 1, 2, 3 ], [ 4, 5, 6 ] ]
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