如何将LPWSTR转换为GUID？ [英] How do I convert a LPWSTR to a GUID?

问题描述

我正在使用Windows 7音频API，我打了墙。

I'm working with the Windows 7 audio APIs, and I've hit a wall.

基本上，我需要一个 IAudioSessionControl2 *并获取 ISimpleAudioVolume *。

Basically, I need to take an IAudioSessionControl2* and get an ISimpleAudioVolume* out of it.

现在，它似乎可以调用 IAudioSessionManager- > GetSimpleAudioVolume（），使用 IAudioSessionControl2的值 - > GetSessionInstanceIdentifier（...）。注意，这不是在文档中完全拼写，但它似乎是一个合理的行为。

Now, it looks like I can call on IAudioSessionManager->GetSimpleAudioVolume() using the value of IAudioSessionControl2->GetSessionInstanceIdentifier(...). Note that this isn't exactly spelled out as such in the docs, but it seems like a reasonable behavior.

问题，GetSimpleAudioVolume（）需要一个GUID *和GetSessionInstanceIdentifier （）发出一个LPWSTR。通过调试，我已经确认来自GetSessionInstanceIdentifier（）的返回值至少看起来像一个GUID

The problem, GetSimpleAudioVolume() takes a GUID* and GetSessionInstanceIdentifier() spits out a LPWSTR. Through debugging I've confirmed that the return'd value from GetSessionInstanceIdentifier() at least looks like a GUID.

是我如何将LPWSTR转换成GUID？我意识到这是非常微不足道，如果我整理成一些托管代码，并使用内置的 GUID ，但是必须有一个C ++的方式来执行此操作。

So, the actual question is how would I convert the LPWSTR I've got into a GUID? I realise this is pretty trivial if I marshal across into some managed code and use built-in GUID, but there's got to be a C++ way of doing this.

不工作的方式我说他们在上面的文本转储。

Ok, these APIs definitely do not work the way I say they do in the above text dump. However, the basic question of String -> GUID is answered so I'm not going to delete the question.

推荐答案

尝试

typedef GUID CLSID;

因此，您可以使用 CLSIDFromString GUID。下面是一些示例代码：

therefore you can use CLSIDFromString to generate a GUID. Here's some sample code:

LPWSTR guidstr;
GUID guid;

...

HRESULT hr = CLSIDFromString(guidstr, (LPCLSID)&guid);
if (hr != S_OK) {
    // bad GUID string...
    ...
}

警告

不是GUID的事件将作为有效的GUID返回。例如：

Warning

Things that are not GUIDs will return as valid GUIDs. For example:

| String              | Returned Clsid                         |
|---------------------|----------------------------------------|
| "file"              | {00000303-0000-0000-C000-000000000046} | FileMoniker
| "AccessControlList" | {b85ea052-9bdd-11d0-852c-00c04fd8d503} |
| "ADODB.Record"      | {00000560-0000-0010-8000-00AA006D2EA4} |
| "m"                 | {4ED063C9-4A0B-4B44-A9DC-23AFF424A0D3} | Toolbar.MySearchDial

这意味着除了返回不期望的结果之外，每次运行它们。

This means that in addition to returning results you do not expect, the function hits the registry every time it is run.

短版本：不要使用CLSIDFromString。而是可以使用 IIDFromString 。

Short version: Do not use CLSIDFromString. Instead you can use IIDFromString in the exact same way.

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