如何在C＃中将对象转换为可空的int数组？

问题描述：

我想在c＃中将对象类型转换为nullable int array（int？[]）但是我没有得到解决方案，任何人都知道如何做到这一点。

Hi,
I want to convert object type to nullable int array (int?[]) in c# but I am not getting nay solution, can anyone know how to do this.

int?[] NullableIntArray{get;set;}

object value = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0];

NullableIntArray = value;


((IEnumerable)propertyValue).Cast<object>().Select(x => x.ToString()).ToArray(); using this I can convert object to string array
where
propertyValue = ["","",""];

我觉得这个对象要int吗？[]。

Thnaks

sushil

我尝试过：

（（IEnumerable）propertyValue）.Cast

答

这将有效。现在好吗？

就个人而言，我不会那样做（但很接近）：

That will work. Does it now?

Personally, I wouldn't do it quite like that (but close):

int?[] result = null;

var enumerable = propertyValue as IEnumerable; 
// will be null if not IEnumerable.  These checks are always valid

if(enumerable != null && enumerable.All(i=>i is int?) //or is INullable<int>.  they should be the same
  result = enumerable.Cast<int?>().ToArray()

return result;

这将返回一个int？[]或null。

就个人而言，我会添加抛出异常的检查，这样我就可以确定为什么我会得到null。毕竟，它可能是一个不同的对象，或者是一个null int？[]。

这不起作用null是int？总是等于false。

相反，替换为i => i == null ||我是int

这是通过的完整单元测试：

This will return either a int?[] or null.

Personally I would add checks that throw exceptions so I can identify why I'm getting null. After all, it might be a different object, or a null int?[].

This did not work as "null is int?" always equals false.

Instead, replace with "i=>i==null || i is int"

Here is the full unit test that passes:

[TestMethod]
public void TryPart1()
{

    int?[] value = new int?[10];
    for (int i = 0; i < value.Length; i++)
    {
        value[i] = (i > 4) ? (int?)null : 0;
    }

    object a = value;
    var result = TryPart2(a);

    Assert.IsTrue(result != null);
    Assert.IsTrue(result.Length == 10);

}

public int?[] TryPart2(object a)
{

    int?[] result = null;

    var enumerable = a as IEnumerable;

    if (enumerable != null)
    {
        var objects = enumerable.Cast<object>().ToArray();
        if (objects.All(o => o==null || o is int))
            result = objects.Cast<int?>().ToArray();

    }

    return result;
}

您需要这样做，我已经在我的机器上测试了这段代码：

You need to to do it something like this, i have tested this code on my machine:

using System;
using System.Linq;
using System.Collections.Generic;
public class HelloWorld
{
	public static void Main()
	{
		
        int?[] NullableIntArray;
        object value = new object[]{"a",0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
        int result;
        NullableIntArray = ((IEnumerable<object>)value)
		                   .Select(x=>int.TryParse(x.ToString(),out result) ? (int?)result : (int?)null)
                           .ToArray();
	}
}

如何在C＃中将对象转换为可空的int数组？

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