I have an object array and I want to convert it to a specific type array. I have the type to convert it into which I get at run time. But I am having a problem doing the actual conversion.
If I use the Convert.ChangeType, I get the error that Object must implement IConvertible
The Array.ConvertAll is template based and requires that I pass the destination type as a template which I only know at run time. I even tried to do use reflection to call this method but I cannot pass the lambda expression as an argument to the Metho开发者_JS百科dInfo.Invoke method.
Any Ideas?
Right I have the following which is not working:
Type convertTo = GetFinalType();
Object[] objArr = GetObjectArray();
var arr = Array.ConvertAll(objArr,elem=> Convert.ChangeType(elem,convertTo));
Have you tried this?
var finalType = GetFinalType();
var objArr = GetObjectArray();
var arr = Array.CreateInstance(finalType, objArr.Length);
Array.Copy(objArr, arr, objArr.Length);
That's untested, but it should work. It's more compact and doesn't (really) use reflection.
You are close; does the following work, or was objType a typo?
Type convertTo = GetFinalType();
Object[] objArr = GetObjectArray();
var arr = Array.ConvertAll(objArr,elem=> Convert.ChangeType(elem, convertTo));
I did it the worst way possible but I managed it somehow. I created a new class
public class Tools
{
public static T[] Convert<T>(object[] objArr)
{
IList<T> list = new List<T>();
foreach (var o in objArr)
{
list.Add((T)o);
}
return list.ToArray();
}
}
And where I needed the conversion, I used:
MethodInfo method = typeof(Tools).GetMethod("Convert");
MethodInfo generic = method.MakeGenericMethod(new Type[] { t });
object o = generic.Invoke(null, new object[] { objArr });
var m = Convert.ChangeType(o,typeof(tArr));
Where
t = typeof(MyClass);
tArr = typeof(MyClass[]);
The code is failing because some object in your array is not a primitive type, or is not something that implements the IConvertible
interface You cannot use Convert.ChangeType()
on such objects.
This is a solution that worked for me:
public static T[] CastArrayToType<T>(object[] collection)
{
return Array.ConvertAll<object, T>(
collection,
delegate(object prop)
{
return (T)prop;
}
);
}
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