在C#中编组引用IntPtr到BSTR *
我试图调用一个为字符串分配内存的函数,然后用字符串做一些事情。以下是说明问题的基本示例:
C ++:
STDMETHODIMP CFunctionsCollection::Function2 (
BSTR leftString, BSTR rightString, BSTR * conString
)
{
int leftLen = lstrlen(leftString);
int rightLen = lstrlen(rightString);
*conString = new TCHAR[leftLen+rightLen+1];
for (int i=0 ; i<leftLen ; ++i)
(*conString)[i] = leftString[i];
for (int i=0 ; i<rightLen ; ++i)
(*conString)[leftLen+i] = rightString[i];
(*conString)[leftLen+rightLen] = 0;
return S_OK;
}
以下来自C ++程序的调用工作得很好:
BSTR leftString = SysAllocString(L"Left String");
BSTR rightString = SysAllocString(L"Right String");
BSTR conString;
hr = pFunctionsCollection->Function2 ( leftString, rightString, & conString);
C#声明:
Int32 Function2([In, MarshalAs(UnmanagedType.BStr)] String leftString,
[In, MarshalAs(UnmanagedType.BStr)] String rightString,
[In, Out] ref IntPtr conStr);
C#电话:
try
{
String leftString = "Left String";
String rightString = "Right String";
IntPtr outStr = IntPtr.Zero;
pFunctionsCollection.Function2(leftString, rightString, ref outStr);
String outString = Marshal.PtrToStringUni(outStr);
Console.WriteLine("Out String = {0}", outString);
}
catch (Exception e)
{
Console.WriteLine("Call to Function2 failed with {0}", e.Message);
}
该计划失败了
调用Function2失败,内存不足,无法继续执行程序。
有谁知道如何从C#进行这样的调用?
没有找到相关结果
已邀请:
1 个回复
凸晴