转换多维数组元素不同类型的 [英] Converting multidimensional array elements to different type

问题描述

假设我有这样的多维数组：

 浮法[] [，]顶点= {
            新的浮动[，] {{0F，1.28f}，{1.28f，2.56f}，{3.84f，2.56f}，{5.12f，1.28f}，{3.84f，0F}，{1.28f，0F} {0F，1.28f}}，
            新的浮动[，] {{0F，3.83f}，{1.27f，5.12f}，{3.87f，5.12f}，{5.12f，3.83f}，{5.12f，1.26f}，{3.87f，0F }，{1.27f，0F}，{0F，1.26f}，{0F，3.83f}}
        };
 

现在，我想每个子阵列转换为类型的数组 Vector2 [] ，其中 Vector2 是一个公共类，其中只包含 X 和是属性：

 公共类Vector2 {
  公众持股量X;
  公众持股量ÿ;  公共Vector2（浮点X，浮法Y）{this.x = X; this.y = Y}
}
 

所以我想构建从Array Vector2元素[2]的元素，这是在上述顶点子数组的数组变量。

我这样做是这样的：

  Array.ConvertAll（顶点[0]
    新的转换器和LT;浮动[]，Vector2＆GT;（verticesSequence =＆GT; {返回新Vector2（verticesSequence [0]，verticesSequence [1]）;}））;
 

然而，作为回报我收到此错误信息：

  

15错误的最好重载方法匹配
  System.Array.ConvertAll（浮动[] []，
  System.Converter）'有一些无效
  参数

解决方案

您有一个数组，其中包含两个数组，每个都包含不同数量的浮动阵列。

Array.ConvertAll 适于通过指定映射委托（一对一）转换一个阵列到另一个。在这种情况下，你不仅要一个浮法[，] 转换成 Vector2 。请注意，您也使用了浮动[] 到 Vector2 转换器，而不是浮动[， ] 到 Vector2 。

像浮法[，] 多维数组也有点棘手，因为他们不支持LINQ开箱即用，它有点难以创造的单班轮这将做所有的映射。

在换句话说，你至少需要一个辅助方法来映射多维数组的项目：

 公共静态的IEnumerable＆LT; Vector2＆GT; ConvertVectors（浮动[，]列表）
{
    对于（INT行= 0;＆行LT; list.GetLength（0）;排++）
    {
        产量返回新Vector2（名单[排，0]，列表[行1]）;
    }
}
 

然后就可以使用了 Array.ConvertAll 方法中：

  VAR转换= Array.ConvertAll＆LT;浮动[，]，Vector2 []＆GT;（
    顶点
    FF =＆GT; ConvertVectors（FF）.ToArray（））;
 

老实说，我会preFER一个LINQ解决方案，因为它会自动推断出所有的通用参数：

 变种R =顶点
    。选择（V =＆GT; ConvertVectors（ⅴ）.ToArray（））
    .ToArray（）;
 

Suppose I have this multidimensional array:

float[][,] vertices = { 
            new float[,]{ {0f, 1.28f}, {1.28f, 2.56f}, {3.84f, 2.56f}, {5.12f, 1.28f}, {3.84f, 0f}, {1.28f, 0f}, {0f, 1.28f} }, 
            new float[,]{ {0f, 3.83f}, {1.27f, 5.12f}, {3.87f, 5.12f}, {5.12f, 3.83f}, {5.12f, 1.26f}, {3.87f, 0f}, {1.27f, 0f}, {0f, 1.26f}, {0f, 3.83f} } 
        };

Now, I want to convert each subarray to an array of type Vector2[] where Vector2 is a public class, which simply contains x and y properties:

public class Vector2 {
  public float x;
  public float y;

  public Vector2(float x, float y) { this.x = x; this.y = y }
}

So I want to construct Vector2 elements from Array[2] elements, which are subarrays in above vertices array variable.

I do it like this:

Array.ConvertAll(vertices[0], 
    new Converter<float[], Vector2>(verticesSequence => { return new Vector2(verticesSequence[0], verticesSequence[1]); }));

However, in return I receive this error message:

Error 15 The best overloaded method match for 'System.Array.ConvertAll(float[][], System.Converter)' has some invalid arguments

解决方案

You have an array, which contains two arrays, each of which contains a different number of float arrays.

Array.ConvertAll is suitable for converting one array into the other by specifying a mapping delegate (one to one). In this case, you don't only have to convert a single float[,] into a Vector2. Note that you also used a float[] to Vector2 converter, instead of float[,] to Vector2.

Multidimensional arrays like float[,] are also a bit tricky since they don't support LINQ out of the box, which it a bit harder to create a one-liner which would do all the mapping.

In other words, you will at least need a helper method to map the items of the multidimensional array:

public static IEnumerable<Vector2> ConvertVectors(float[,] list)
{
    for (int row = 0; row < list.GetLength(0); row++)
    {
        yield return new Vector2(list[row, 0], list[row, 1]);
    }
}

And then you can use that inside the Array.ConvertAll method:

var converted = Array.ConvertAll<float[,], Vector2[]>(
    vertices,
    ff => ConvertVectors(ff).ToArray());

Honestly, I would prefer a LINQ solution because it will infer all the generic parameters automatically:

var r = vertices
    .Select(v => ConvertVectors(v).ToArray())
    .ToArray();

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