Array.LongLength属性用于获取一个64位整数，该整数表示Array所有维度中的元素总数。
句法：
public long LongLength { get; }属性值：该属性返回一个64位整数，该整数代表数组所有维度中元素的总数。
例子：
// C# program to illustrate the
// Array.LongLength Property
using System;
namespace geeksforgeeks {
class GFG {
// Main Method
public static void Main()
{
// Two-dimensional array
int[, ] intarray = new int[, ] { { 1, 2 },
{ 3, 4 },
{ 5, 6 },
{ 7, 8 } };
// The same array with dimensions
// specified 4 row and 2 column.
int[, ] intarray_d = new int[4, 2] { { 1, 2 },
{ 3, 4 },
{ 5, 6 },
{ 7, 8 } };
Console.Write("Total Number of Elements in intarray: ");
// using LongLength property
Console.Write(intarray.LongLength);
// getting the type of returned value
Console.WriteLine("\nType of returned Length: "
+ (intarray.LongLength).GetType());
// showing difference between Length
// and LongLength property by getting
// the type of the both property's
// returned value
Console.Write("\nTotal Number of Elements in intarray_d: ");
// using Length property
Console.Write(intarray_d.Length);
// getting the type of returned value
Console.WriteLine("\nType of returned Length: "
+ (intarray_d.Length).GetType());
Console.Write("\nTotal Number of Elements in intarray_d: ");
// using LongLengthLength property
Console.Write(intarray_d.LongLength);
// getting the type of returned value
Console.WriteLine("\nType of returned Length: "
+ (intarray_d.LongLength).GetType());
}
}
}
输出：
Total Number of Elements in intarray: 8
Type of returned Length: System.Int64
Total Number of Elements in intarray_d: 8
Type of returned Length: System.Int32
Total Number of Elements in intarray_d: 8
Type of returned Length: System.Int64
注意：在上面的程序中，您可以看到Array.Length属性始终返回System.Int32类型的长度，但是Array.LongLength属性始终返回System.Int64类型的长度。
参考：
- https://docs.microsoft.com/zh-cn/dotnet/api/system.array.longlength?view=netframework-4.7.2