在通过反射阵列设定值 [英] Setting value in an array via reflection

问题描述

有没有办法通过反射在C＃中设置一个数组属性单一值？

Is there a way to set a single value in an array property via reflection in c#?

我的属性是这样定义的：

My property is defined like this:

double[]    Thresholds      { get; set; }

有关正常的性质我用这个code通过反射来进行设置：

For "normal" properties I use this code to set it via reflection:

PropertyInfo pi = myObject.GetType().GetProperty(nameOfPropertyToSet);
pi.SetValue(myObject, Convert.ChangeType(valueToSet, pi.PropertyType), null);

我如何将不得不改变这个code设置在任意位置数组中的属性的值？
谢谢！

How would I have to change this code to set the value in an array property at an arbitrary position? Thanks!

BTW：我试图使用索引参数，但似乎只为索引的属性，没有属性是数组工作...

BTW: I tried to use the index parameter, but that seems only to work for indexed properties, not properties that are arrays...

推荐答案

当你这样做：

obj.Thresholds[i] = value;

这是语义上等价于：

double[] tmp = obj.Thresholds;
tmp[i] = value;

这意味着你不希望的SetValue 的所有的;相反，要使用的GetValue 来获得数组，然后变异的数组。如果类型是已知的双[] ，则：

which means you don't want a SetValue at all; rather, you want to use GetValue to obtain the array, and then mutate the array. If the type is known to be double[], then:

double[] arr = (double[]) pi.GetValue(myObject, null);
arr[i] = value;

否则也许非通用的IList 办法（因为数组实施的IList ）

IList arr = (IList) pi.GetValue(myObject, null);
arr[i] = value;

如果它是一个多维数组，你将不得不使用阵列在的IList 的。

If it is a multi-dimensional array, you'll have to use Array in place of IList.

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