【转】VB VC 混合编程(dll)中 数组 的传入传出

原文地址：http://hi.baidu.com/hfutgiser/blog/item/63418858a4f09f87810a187e.html

       以前用到的神经网络都是在matlab中调的，而项目需要，要写个神经网络的算法，系统主界面是VB写的，在VB中做网络训练速度是不照的，用VB，VC的混合编程，但是一直被VB与Dll之间的数组传递这个难题所困扰，在网上搜了也找不到答案，据说safearray可以解决，但是看了下比较麻烦，在CSDN社区中也没有找到答案，但是社区中一个朋友的指点，给我找到解决问题的方法了。下面总结下共享。
    数值型数组在VB中其数据是连续存放的，相当于一维的，而在C/C++中数组可以等价于指向数组第1个元素的指针。可以用引用的方式把VB中数组的第1个元素的地址传给VC编写的DLL，在DLL中用一个指针来接收，这样就实现了VB到Dll在中数组的传递。从DLL传递数组给VB方法相同，过程相反.
    如果是二维数组，则把二维数组按照一维数组的方式传入传出，只是在使用的时候，顺便把二维数组的行和列数传递即可。
    总体思想是这样的。下面看例子。

VC中：

double _stdcall OneDimensionArrayTest(double *inArr,int nCount,double *outArr,int* ioutArrCount) //一维数组的传入传出
{
    int iNum=nCount;
     double *dRes=new double[iNum];
    int i;
     for(i=0;i<nCount;i++)
     {
         dRes[i]=inArr[i]*2;
     }

    for(i=0;i<nCount;i++)
     {
         outArr[i]=dRes[i];
     }
    *ioutArrCount=iNum;
     return dRes[0];
     delete []dRes;
}


void _stdcall TwoDimensionArrayTest(double *inArr,int nRows,int nCols,double *outArr,int* outRows,int *outCols)//二维数组的传入传出
{
     double *dRes=new double[nRows*nCols];
    int i;
     int j;
     for(i=0;i<nRows;i++)
     {
         for(j=0;j<nCols;j++)
         {
             dRes[nCols*i+j]=inArr[nCols*i+j]*2;
         }
     }
     for(i=0;i<nRows;i++)
     {
         for(j=0;j<nCols;j++)
         {
             outArr[nCols*i+j]=inArr[nCols*i+j]*2;
         }
     }
    *outRows=nRows;
     *outCols=nCols;
     delete [] dRes;
}


LIBRARY      "TestDll"

EXPORTS
    ; 此处可以是显式导出
    Add @1
    darray @2
    OneDimensionArrayTest @3
TwoDimensionArrayTest @4

VB中
Declare Function OneDimensionArrayTest Lib "D:\在编程序\Dll\VBLoadDll\TestDll.dll" (ByRef inputer As Double, ByVal inLength As Long, ByRef output As Double, ByRef outLength As Long) As Double
Declare Function TwoDimensionArrayTest Lib "D:\在编程序\Dll\VBLoadDll\TestDll.dll" (ByRef inputer As Double, ByVal inRows As Long, ByVal inCols As Long, ByRef outputer As Double, ByRef outRows As Long, ByRef outCols As Long)

Private Sub cmdTest2_Click()
Dim inputer(8) As Double
Dim out(9) As Double
Dim res As Double
Dim m As Long
inputer(0) = 1.2
inputer(1) = 2.3
inputer(2) = 1
res = OneDimensionArrayTest(inputer(0), 9, out(0), m)
MsgBox CStr(m), vbOKOnly, "一维数组的元素个数"

'MsgBox CStr(res)

Dim str As String
Dim i As Integer
For i = 0 To UBound(out)
   str = str + "   " + CStr(out(i))
Next
MsgBox str, vbOKOnly, "一维数组的元素"
End Sub

Private Sub cmdTest3_Click()
Dim iRows As Integer
Dim iCols As Integer
iRows = 3
iCols = 4
Dim inputer() As Double
ReDim inputer(iRows, iCols)
Dim outputer() As Double
ReDim outputer(iRows, iCols)
Dim oRows As Long
Dim oCols As Long
Dim i, j As Integer
For i = 0 To UBound(inputer, 1)
   For j = 0 To UBound(inputer, 2)
     inputer(i, j) = (i + 1) * (j + 1)
   Next
Next
Dim str As String
For i = 0 To UBound(inputer, 1)
   For j = 0 To UBound(inputer, 2)
      str = str + "   " + CStr(inputer(i, j))
   Next
   str = str + vbCrLf
Next
MsgBox str, vbOKOnly, "inputer，二维数组的输入"

Call TwoDimensionArrayTest(inputer(0, 0), iRows + 1, iCols + 1, outputer(0, 0), oRows, oCols)

str = ""
'
For i = 0 To UBound(outputer, 1)
   For j = 0 To UBound(outputer, 2)
      str = str + "   " + CStr(outputer(i, j))
   Next
   str = str + vbCrLf
Next
MsgBox str, vbOKOnly, "outputer，二维数组的输出"
End Sub
笨方法，很简单，但是真的可以用