C# 如何把int[][]转换成int[*,*]

//{0,0}
//{1,0}
//{2,0}
//{3,0}
//{4,0}
//{5,0}

list<int[]> lstint = new list<int[]>();
for (int i = 0; i < dt.rows.count; i++)
{
int[] inttemp = array.convertall<string, int>(dt.rows[i]["pos"].tostring().split(‘,‘), s => int.parse(s));
lstint.add(inttemp);

}
//int[][] blk_pos = lstint.toarray();
int[,] blk_pos = tomultidimensionalarray(lstint);

//转换方法

static int[,] tomultidimensionalarray(list<int[]> arraylist)
{
int[,] mdarray = new int[arraylist.count, arraylist[0].length];
int rowindex = 0;
arraylist.foreach(x =>
{
buffer.blockcopy(
x, // src
0, // srcoffset
mdarray, // dst
rowindex++ * mdarray.getlength(1) * sizeof(int), // dstoffset
x.length * sizeof(int)); // count
});

return mdarray;
}