Array.GetLongLength(Int32)方法用于获取一个64位整数，该整数表示Array指定维中的元素数。
句法：
public long GetLongLength (int dimension);这里，维度是要计算其长度的数组的从零开始的维度。
返回值：返回一个64-bit整数，该整数表示指定维中的元素数。
异常：如果维度小于零或大于或等于Rank，则此方法将引发IndexOutOfRangeException 。
例子：
// C# program to illustrate the
// Array.GetLongLength() method
using System;
namespace geeksforgeeks {
class GFG {
// Main Method
public static void Main()
{
// Three-dimensional array.
int[,, ] arr = new int[,, ] {
{ { 1, 2, 3 },
{ 4, 5, 6 },
{ 6, 7, 8 }
},
{ { 11, 12, 13 },
{ 14, 15, 16 },
{ 17, 18, 19 }
},
{ { 21, 22, 23 },
{ 24, 25, 26 },
{ 27, 28, 29 }
},
};
Console.Write("Total Number of Elements in"
+ " first dimension of arr: ");
// using GetLongLength Method
Console.Write(arr.GetLongLength(0));
// getting the type of returned value
Console.WriteLine("\nType of returned Length: "
+ (arr.GetLongLength(0)).GetType());
// showing difference between GetLength
// and GetLongLength method by getting
// the type of the both method's
// returned value
Console.Write("\nTotal Number of Elements in "
+ "second dimension of arr: ");
// using GetLength Method
Console.Write(arr.GetLength(1));
// getting the type of returned value
Console.WriteLine("\nType of returned Length: "
+ (arr.GetLength(1)).GetType());
Console.Write("\nTotal Number of Elements in "
+ "second dimension of arr: ");
// using GetLongLength() Method
Console.Write(arr.GetLongLength(1));
// getting the type of returned value
Console.WriteLine("\nType of returned Length: "
+ (arr.GetLongLength(1)).GetType());
}
}
}
输出：
Total Number of Elements in first dimension of arr: 3
Type of returned Length: System.Int64
Total Number of Elements in second dimension of arr: 3
Type of returned Length: System.Int32
Total Number of Elements in second dimension of arr: 3
Type of returned Length: System.Int64
注意：在上述程序中， GetLength方法的返回类型为System.Int32但GetLongLength方法的返回类型为System.Int64 。
参考：
- https://docs.microsoft.com/zh-cn/dotnet/api/system.array.getlonglength?view=netframework-4.7.2