使用GDIPlus显示存储为alpha资源的图标（WIn32 C ++） [英] Displaying Icons stored as resources with alpha using GDIPlus (WIn32 C++)

问题描述

我想要使用GDIPlus显示部分alpha（alpha值介于0到255之间）的图标。当使用采用直接文件名的GDI +的Bitmap构造函数时，文件会正确显示。但是，从资源加载时，它在识别alpha时出现问题。我查看了MSDN，但是alpha存在问题： http：/ /msdn.microsoft.com/en-us/library/windows/desktop/ms536318.aspx 。通过从Icon中检索ICONINFO结构，我可以摆脱完全透明的像素，但是，部分透明像素仍然显示为完全不透明或完全透明。

I have an icon with partial alpha (alpha values between 0 and 255) that I want to display using GDIPlus. When using the Bitmap constructor of GDI+ that takes the direct filename, the file displays properly. However, when loading from resource, it has a problem recognizing alpha. I looked on MSDN, and there are problems with alpha: http://msdn.microsoft.com/en-us/library/windows/desktop/ms536318.aspx. By retrieving the ICONINFO structure from the Icon, I can get rid of the fully transparent pixels, however, the partially transparent pixels still appear either as fully opaque or fully transparent.

我想知道如何使用部分alpha值从资源中的Icon创建Win32位图。

I wanted to know how to create a Win32 Bitmap from an Icon in resource with the partial alpha values.

推荐答案

您可以使用 LoadResource 获取指向图标及其图像数据的指针。您可以将指向图像数据的指针传递给相应的位图构造函数。这是一件苦差事，因为图标有特殊资源格式。

You can use LoadResource to get a pointer to the icon and and its image data. You can pass the pointer to the image data to the appropriate Bitmap constructor. This is a bit of a chore because icons have a peculiar resource format.

如果可能，将图像存储为透明（即32bpp argb）位图会更简单。在这种情况下，您可以使用 LoadImage 使用LR_CREATEDIBSECTION。

If possible, it would be simpler to store your image as a transparent (i.e. 32bpp argb) bitmap. In this case you can use LoadImage with LR_CREATEDIBSECTION.

更新

显然LoadIcon确实加载了alpha正确。当你从HICON构造一个GdiPlus :: Bitmap时，问题似乎是GdiPlus不尊重alpha。你能做的是：

Apparently LoadIcon does load the alpha correctly. It would appear that the problem is GdiPlus not respecting the alpha when you construct a GdiPlus::Bitmap from an HICON. What you could do is:

• 使用LoadIcon加载图标。


• 使用GetIconInfo获取ICONINFO。 hbmColor是透明位图的句柄。


• 使用GetDIBits从hbmColor获取位图位。


• 将数据传递给位图构造函数，需要理解和理解alpha。

• Use LoadIcon to load the icon.
• Use GetIconInfo to get the ICONINFO. hbmColor is the handle of the transparent bitmap.
• Use GetDIBits to get the bitmap bits from hbmColor.
• Pass the data to the Bitmap constructor that takes bits and understands alpha.

这篇关于使用GDIPlus显示存储为alpha资源的图标（WIn32 C ++）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IT屋！