从 SHGetFileInfo() 返回的图标的最大大小是多少？

Question

使用 SHGetFileInfo() 函数，我可以获得的图标的最大尺寸是多少？就函数状态而言，我可以取回一个 32x32 像素的图标（又名 SHGFI_LARGEICON）。但我想弄清楚是否有办法得到更大的东西，比如 48x48 像素的图标。

我发现有常量，例如...

public const uint SHGFI_LARGEICON = 0x000000000;     // get large icon
public const uint SHGFI_SMALLICON = 0x000000001;     // get small icon
public const uint SHIL_JUMBO = 0x000000004;     // get jumbo icon 256x256
public const uint SHIL_EXTRALARGE = 0x000000002;     // get extra large icon 48x48
public const uint SHIL_LARGE = 0x000000000;     // get large icon 32x32
public const uint SHIL_SMALL = 0x000000001;     // get small icon 16x16
public const uint SHIL_SYSSMALL = 0x000000003;     // get icon based off of GetSystemMetrics

...但我不确定这些是否对 SHGetFileInfo() 有效。我试过了，图标看起来很模糊而且不正确。（它们看起来 clear/nice 不像 Windows Explorer 中的那些，你使用 View: Medium Icons 设置）

这就是我所拥有的（注意：这不是一个有效的解决方案，SHIL 值没有记录在 SHGetFileInfo() 函数中。这只是我尝试的东西。）...

public const uint SHIL_JUMBO = 0x000000004;     // get jumbo icon 256x256
public const uint SHIL_EXTRALARGE = 0x000000002;     // get extra large icon 48x48
public const uint SHIL_LARGE = 0x000000000;     // get large icon 32x32
public const uint SHIL_SMALL = 0x000000001;     // get small icon 16x16
public const uint SHIL_SYSSMALL = 0x000000003;     // get icon based off of GetSystemMetrics
public const uint SHGFI_ICON = 0x000000100;     // get icon
public const uint SHGFI_OPENICON = 0x000000002;     // get open icon

[DllImport("Shell32.dll")]
public static extern IntPtr SHGetFileInfo(
    IntPtr pszPath,
    uint dwFileAttributes,
    ref SHFILEINFO psfi,
    uint cbFileInfo,
    uint uFlags
);
[DllImport("User32.dll")]
public static extern int DestroyIcon(IntPtr hIcon);

public struct SHFILEINFO
{
    public const int NAMESIZE = 80;
    public IntPtr hIcon;
    public int iIcon;
    public uint dwAttributes;
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = MAX_PATH)]
    public string szDisplayName;
    [MarshalAs(UnmanagedType.ByValTStr, SizeConst = NAMESIZE)]
    public string szTypeName;
}

public enum IconSize
{
    Jumbo = 4, //256x256
    ExtraLarge = 2, //48x48
    Large = 0, //32x32
    Small = 1 //16x16
}

IconSize size = IconSize.ExtraLarge;

uint flags = SHGFI_ICON;
flags |= SHGFI_OPENICON;
switch (size)
{
    case IconSize.Small:
        flags |= SHIL_SMALL;
        break;
    case IconSize.Large:
        flags |= SHIL_LARGE;
        break;
    case IconSize.ExtraLarge:
        flags |= SHIL_EXTRALARGE;
        break;
    case IconSize.Jumbo:
        flags |= SHIL_JUMBO;
        break;
}

//Get me a PDIL to the My Documents folder (this is done with a LOT of other
//code but I know for a fact it returns the name, path, and PDIL correctly!
CGFolder cFolder = new CGFolder(Environment.SpecialFolder.MyDocuments);

string sName = cFolder.Pidl.DisplayName;   
string sPath = cFolder.Pidl.PhysicalPath;
IntPtr ptrPDIL = cFolder.Pidl.Pidl;
SHFILEINFO shfi = new SHFILEINFO();
SHGetFileInfo(ptrPDIL, 0, ref shfi, (uint)Marshal.SizeOf(shfi), flags);

if (shfi.hIcon == IntPtr.Zero) return null;

icon = (Icon)Icon.FromHandle(shfi.hIcon).Clone();

DestroyIcon(shfi.hIcon);

return icon;

参考文献：

http://msdn.microsoft.com/en-us/library/windows/desktop/bb762179%28v=vs.85%29.aspx)

Answer 1

系统图像列表中的索引对于所有图标大小都是相同的，因此使用 SHGetFileInfo 和 SHGFI_SYSICONINDEX 标志获取索引，并使用 imagelist API to extract it from the "extra-large" or "jumbo" image lists which you can get from the SHGetImageList 函数。

SHGetFileInfo 本身只能 return 小的（例如 16x16）和大的（例如 32x32）HICON。

从 SHGetFileInfo() 返回的图标的最大大小是多少？

What is the Maximum Size Of An Icon Returned From SHGetFileInfo()?

c#

winapi

icons

pinvoke

dllimport