如何将一行值从二维数组复制到一维数组中?

int[,] oGridCells = {{1, 2}, {3, 4}};
int[] oResult = new int[4];
System.Buffer.BlockCopy(oGridCells, 0, oResult, 0, 16);

您还可以通过提供正确的字节偏移量,从数组中选择性地复制一行。此示例复制3行二维阵列的中间行。

int[,] oGridCells = {{1, 2}, {3, 4}, {5, 6}};
int[] oResult = new int[2];
System.Buffer.BlockCopy(oGridCells, 8, oResult, 0, 8);

unsafe code . 完整示例,显示了两种方式,如下所示:

public class MultiSingleUnsafe
{
    public static unsafe void Main(String[] a)
    {
    int rowCount = 6;
    int iUpperBound = 10;
    int [,] oGridCells = new int[rowCount, iUpperBound];

    int iIndex = rowCount - 2; // Pick a row.

    for(int i = 0; i < iUpperBound; i++)
    {
        oGridCells[iIndex, i] = i;
    }

    for (int iLoop = 0; iLoop < iUpperBound; iLoop++)
    {
        //Get the value from the 2D array
        int iValue = oGridCells[iIndex, iLoop];
        Console.WriteLine("Multi-dim array access iValue: " + iValue);
        //Do something with iValue
    }
    
    fixed(int *lastRow = &(oGridCells[iIndex,0]))
    {   
        for (int iLoop = 0; iLoop < iUpperBound; iLoop++)
        {
        int iValue = lastRow[iLoop];
        Console.WriteLine("Pointer access iValue: " + iValue);
        }
    }
    }
}

如果可能的话,我会大吃一惊:我打赌 oGridCells[iIndex, iLoop] 只是一种缩写(在MSIL内部),用于 oGridCells[iIndex * iLoop]

无法获取对每个数组的引用。但是,您可以使用 jagged array

“但是如果数组被严重操纵,那么一维数组将比多维数组更有效。”

去年夏天我做了一些分析,很惊讶地发现2D和1D阵列在性能上没有显著差异。

我没有测试锯齿阵列的性能。

您可以尝试以下方法:

 int[,] twoD = new int[2,2];
 twoD[0, 0] = 1;
 twoD[0, 1] = 2;
 twoD[1, 0] = 3;
 twoD[1, 1] = 4;

 int[] result = twoD.Cast<int>().Select(c => c).ToArray();

1, 2, 3, 4