Last night I had dream that the following was impossible. But in the same dream, someone 开发者_JS百科from SO told me otherwise. Hence I would like to know if it it possible to convert System.Array
to List
Array ints = Array.CreateInstance(typeof(int), 5);
ints.SetValue(10, 0);
ints.SetValue(20, 1);
ints.SetValue(10, 2);
ints.SetValue(34, 3);
ints.SetValue(113, 4);
to
List<int> lst = ints.OfType<int>(); // not working
Save yourself some pain...
using System.Linq;
int[] ints = new [] { 10, 20, 10, 34, 113 };
List<int> lst = ints.OfType<int>().ToList(); // this isn't going to be fast.
Can also just...
List<int> lst = new List<int> { 10, 20, 10, 34, 113 };
or...
List<int> lst = new List<int>();
lst.Add(10);
lst.Add(20);
lst.Add(10);
lst.Add(34);
lst.Add(113);
or...
List<int> lst = new List<int>(new int[] { 10, 20, 10, 34, 113 });
or...
var lst = new List<int>();
lst.AddRange(new int[] { 10, 20, 10, 34, 113 });
There is also a constructor overload for List that will work... But I guess this would required a strong typed array.
//public List(IEnumerable<T> collection)
var intArray = new[] { 1, 2, 3, 4, 5 };
var list = new List<int>(intArray);
... for Array class
var intArray = Array.CreateInstance(typeof(int), 5);
for (int i = 0; i < 5; i++)
intArray.SetValue(i, i);
var list = new List<int>((int[])intArray);
Interestingly no one answers the question, OP isn't using a strongly typed int[]
but an Array
.
You have to cast the Array
to what it actually is, an int[]
, then you can use ToList
:
List<int> intList = ((int[])ints).ToList();
Note that Enumerable.ToList
calls the list constructor that first checks if the argument can be casted to ICollection<T>
(which an array implements), then it will use the more efficient ICollection<T>.CopyTo
method instead of enumerating the sequence.
The simplest method is:
int[] ints = new [] { 10, 20, 10, 34, 113 };
List<int> lst = ints.ToList();
or
List<int> lst = new List<int>();
lst.AddRange(ints);
In the case you want to return an array of enums as a list you can do the following.
using System.Linq;
public List<DayOfWeek> DaysOfWeek
{
get
{
return Enum.GetValues(typeof(DayOfWeek))
.OfType<DayOfWeek>()
.ToList();
}
}
in vb.net just do this
mylist.addrange(intsArray)
or
Dim mylist As New List(Of Integer)(intsArray)
You can do like this basically:
int[] ints = new[] { 10, 20, 10, 34, 113 };
this is your array, and than you can call your new list like this:
var newList = new List<int>(ints);
You can do this for complex object too.
You can just give it try to your code:
Array ints = Array.CreateInstance(typeof(int), 5);
ints.SetValue(10, 0);
ints.SetValue(20, 1);
ints.SetValue(10, 2);
ints.SetValue(34, 3);
ints.SetValue(113, 4);
int[] anyVariable=(int[])ints;
Then you can just use the anyVariable as your code.
I know two methods:
List<int> myList1 = new List<int>(myArray);
Or,
List<int> myList2 = myArray.ToList();
I'm assuming you know about data types and will change the types as you please.
Just use the existing method.. .ToList();
List<int> listArray = array.ToList();
KISS(KEEP IT SIMPLE SIR)
I hope this is helpful.
enum TESTENUM
{
T1 = 0,
T2 = 1,
T3 = 2,
T4 = 3
}
get string value
string enumValueString = "T1";
List<string> stringValueList = typeof(TESTENUM).GetEnumValues().Cast<object>().Select(m =>
Convert.ToString(m)
).ToList();
if(!stringValueList.Exists(m => m == enumValueString))
{
throw new Exception("cannot find type");
}
TESTENUM testEnumValueConvertString;
Enum.TryParse<TESTENUM>(enumValueString, out testEnumValueConvertString);
get integer value
int enumValueInt = 1;
List<int> enumValueIntList = typeof(TESTENUM).GetEnumValues().Cast<object>().Select(m =>
Convert.ToInt32(m)
).ToList();
if(!enumValueIntList.Exists(m => m == enumValueInt))
{
throw new Exception("cannot find type");
}
TESTENUM testEnumValueConvertInt;
Enum.TryParse<TESTENUM>(enumValueString, out testEnumValueConvertInt);
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