COM：使用VT_BSTR值创建VT_ARRAY [英] COM: Create a VT_ARRAY with VT_BSTR values

问题描述

我是一个COM新手，我认为我有正确的，但运行时不喜欢它。任何帮助是非常感激。

我需要调用一个接收一个一维数组的BSTR的COM函数。具体来说，文档说参数必须是：

功能：AddFiles（[in] VARIANT * filePaths）

filePaths 每个文件或
文件夹的完整路径的单维数组。 filePaths可以是类型
VT_ARRAY | VT_VARIANT ，其中每个条目
是 VT_BSTR 或 VT_ARRAY | VT_BSTR 。

我有一个 vector< wstring> myPaths 的路径，我想传递到接受上面的参数的函数。这里是我写的代码。在myComObject上调用AddFiles导致一个AV（myComObject不为null，我可以调用其他方法）：

  .. 。
 VARIANT filePaths; 
 VariantInit（& filePaths）; 
 filePaths.vt = VT_ARRAY | VT_VARIANT; 
 filePaths.parray = SafeArrayCreateVector（VT_BSTR，0，（unsigned int）myPaths.size（））; 
 
 long i = 0; 
 for（vector< wstring> :: iterator it = myPaths.begin（）; 
 it！= myPaths.end（）; 
 it ++，i ++）
 {
 BSTR myPath = SysAllocString（it-> c_str（））; 
 SafeArrayPutElement（filePaths.parray，& i，myPath） 
} 
 
 myComObject-> AddFiles（& filePaths）; 
 ... 
  

COM对象不是我的代码，但是我怀疑我没有正确地创建这个数组 - 根据AddFiles函数和代码我的需求，任何人都有想法我可能会做错了什么？

AddFiles只能处理VT_ARRAY | VT_VARIANT，以下应该也可以工作。

  VARIANT myPath; 
 VariantInit（& myPath）; 
 
 myPath.vt = VT_BSTR; 
 myPath.bstrVal = SysAllocString（it-> c_str（））; 
 
 SafeArrayPutElement（filePaths.parray，& i，& myPath）; 
  

I'm a COM newbie and I think what I have is correct, but the runtime doesn't like it. Any help is much appreciated.

I need to invoke a COM function that takes in a single dimensional array of BSTRs. Specifically, the documentation says the parameter must be:

Function: AddFiles ( [in] VARIANT * filePaths )

filePaths The single-dimensioned array of full paths to each file or folder. filePaths can be of type VT_ARRAY|VT_VARIANT, where each entry is a VT_BSTR, or VT_ARRAY|VT_BSTR.

I have a vector<wstring> myPaths of paths which I want to pass into the function that takes the parameter above. Here's the code I wrote. Calling AddFiles on myComObject results in an AV (myComObject is not null, and I can invoke other methods on it):

        ...
        VARIANT filePaths;
        VariantInit( &filePaths );
        filePaths.vt = VT_ARRAY|VT_VARIANT;
        filePaths.parray = SafeArrayCreateVector( VT_BSTR, 0, (unsigned int) myPaths.size() );

        long i = 0;
        for( vector<wstring>::iterator it = myPaths.begin();
            it != myPaths.end();
            it++, i++ )
        {
            BSTR myPath= SysAllocString(it->c_str());
            SafeArrayPutElement( filePaths.parray, &i, myPath);
        }

        myComObject->AddFiles( &filePaths );
        ...

The COM object isn't my code and I can't debug into it, but I suspect I'm not creating that array properly - based on the requirement of the AddFiles function and the code I have, anyone have ideas about what I might be doing wrong?

解决方案

If myComObject->AddFiles can only deal with VT_ARRAY|VT_VARIANT, the following should work too.

VARIANT myPath;
VariantInit(&myPath);

myPath.vt = VT_BSTR;
myPath.bstrVal = SysAllocString(it->c_str());

SafeArrayPutElement(filePaths.parray, &i, &myPath);

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