问题描述
GDI + 方法需要一个CLSID参数来指定要使用的编码器。文档指向,用于获取与编码器相关联的特定的MIME类型,例如image / jpeg或image / png。然而,我只是为了支持一个单行调试助手,我把中间结果保存到磁盘上,我想要复制一个半页函数。
The GDI+ Image::Save
method requires a CLSID parameter to specify the encoder to use. The documentation points to some sample code for getting the encoder associated with a particular MIME type, such as image/jpeg or image/png. However I'm balking at the thought of copying a half-page function just to support a 1-line debugging aid where I save an intermediate result out to disk.
Shouldn有标准编码器的标准CLSID列表吗?我在哪里可以找到这样的列表?我无法通过搜索Microsoft的包含文件找到一个。
Shouldn't there be a list of standard CLSIDs for the standard encoders? Where would I find such a list? I haven't been able to find one by searching Microsoft's include files.
推荐答案
没有一个。我认为他们打算的编解码器列表是可扩展的,并支持插件,但从来没有得到它。鉴于他们在相当长的时间内没有对GDI +进行任何更改,他们很可能不会很快。您可以根据Gdiplus :: GetImageEncoders的枚举生成自己的硬编码列表。
There isn't one. I think they intended the codec list to be extensible and support plugins, but never got around to it. Given that they haven't made any changes to GDI+ in quite some time, they likely won't anytime soon. You could probably get away with generating your own hard coded list based on an enumeration of Gdiplus::GetImageEncoders.
这是:
image/bmp : {557cf400-1a04-11d3-9a73-0000f81ef32e}
image/jpeg : {557cf401-1a04-11d3-9a73-0000f81ef32e}
image/gif : {557cf402-1a04-11d3-9a73-0000f81ef32e}
image/tiff : {557cf405-1a04-11d3-9a73-0000f81ef32e}
image/png : {557cf406-1a04-11d3-9a73-0000f81ef32e}
这里是我常规剪切和粘贴项目之间的函数以获取CLSID的函数编码器。您可以将其修改为表查找。
Here's the function I routinely cut&paste between projects for getting at the CLSID of the encoder. You could modify it to be a table lookup.
HRESULT GetGdiplusEncoderClsid(__in LPCWSTR pwszFormat, __out GUID *pGUID)
{
HRESULT hr = E_FAIL;
UINT nEncoders = 0; // number of image encoders
UINT nSize = 0; // size of the image encoder array in bytes
CAutoVectorPtr<BYTE> spData;
Gdiplus::ImageCodecInfo* pImageCodecInfo = NULL;
Gdiplus::Status status;
bool fFound = false;
// param check
if ((pwszFormat == NULL) || (pwszFormat[0] == 0) || (pGUID == NULL))
{
return E_POINTER;
}
*pGUID = GUID_NULL;
status = Gdiplus::GetImageEncodersSize(&nEncoders, &nSize);
if ((status != Gdiplus::Ok) || (nSize == 0))
{
return E_FAIL;
}
spData.Allocate(nSize);
if (spData == NULL)
{
return E_FAIL;
}
pImageCodecInfo = (Gdiplus::ImageCodecInfo*)(BYTE*)spData;
status = Gdiplus::GetImageEncoders(nEncoders, nSize, pImageCodecInfo);
if (status != Gdiplus::Ok)
{
return E_FAIL;
}
for(UINT j = 0; j < nEncoders; ++j)
{
if( wcscmp(pImageCodecInfo[j].MimeType, pwszFormat) == 0 )
{
*pGUID = pImageCodecInfo[j].Clsid;
fFound = true;
break;
}
}
hr = fFound ? S_OK : E_FAIL;
return hr;
}
这篇关于GDI +有标准的图像编码器CLSID吗?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!