从Delphi调用SHGetSetSettings [英] Calling SHGetSetSettings from Delphi

问题描述

我刚读了这个问题和这个问题，从那以后，我一直在试图调用 SHGetSetSettings 。这是 shell32.dll 的功能，但在 ShlObj.pas 中未定义，所以我们需要写我们的自己定义。

I just read this question and this question, and since then I have been trying to call SHGetSetSettings in Delphi. This is a function of shell32.dll, but is not defined in ShlObj.pas, so we need to write our own definition.

首先我们需要翻译 SHELLSTATE 结构。现在我在C中只有有限的经验，但我认为：1表示结构的成员是一个位，也就是说，它们中的八个可以一个字节打包在一起。我还假设 DWORD = UINT = 32位无符号整数，而 LONG = int 是32位有符号整数。但是我们有一个问题：整个结构将占用228位或28.5字节，这是...相当不可能，至少在Delphi中，其中 sizeof（SomeRecord）必须是一个整数。

First we need to translate the SHELLSTATE structure. Now I have only limited experience in C, but I suppose that ": 1" means that the member of the structure is a single bit, that is, that eight of them can be packed together in a byte. I also suppose that DWORD = UINT = 32-bit unsigned integers and that LONG = int are 32-bit signed integers. But then we have a problem: The entire structure will then occupy 228 bits, or 28.5 bytes, which is ... rather impossible, at least in Delp where sizeof(SomeRecord) has to be an integer.

然而，我试图通过在结尾添加四个虚拟位来解决它。 232位= 29字节，这是很好的。

Nevertheless, I tried to solve it by adding four dummy bits at the end. 232 bits = 29 bytes, which is nice.

所以我尝试了

PShellState = ^TShellState;
TShellState = packed record
  Data1: cardinal;
  Data2: cardinal;
  Data3: cardinal;
  Data4: cardinal;
  Data5: cardinal;
  Data6: cardinal;
  Data7: cardinal;
  Data8: byte; // Actually a nibble would be sufficient
end;

然后我宣布（以便方便）

and then I declared (for later convenience)

const
  fShowAllObjects = 1;
  fShowExtensions = 2;
  fNoConfirmRecycle = 4;
  fShowSysFiles = 8;
  fShowCompColor = 16;
  fDoubleClickInWebView = 32;
  fDesktopHTML = 64;
  fWin95Classic = 128;
  fDontPrettyPath = 256;
  fShowAttribCol = 512;
  fMapNetDrvButton = 1024;
  fShowInfoTip = 2048;
  fHideIcons = 4096;
  fWebView = 8192;
  fFilter = 16384;
  fShowSuperHidden = 32768;
  fNoNetCrawling = 65536;

现在我已经准备好定义

interface
  procedure SHGetSetSettings(var ShellState: TShellState; Mask: cardinal; DoSet: boolean); stdcall;

implementation
  procedure SHGetSetSettings; external shell32 name 'SHGetSetSettings';

但是，在我尝试代码之前，我注意到一些非常奇怪的东西。我发现我声明的常数已经在这里被声明： SSF常数请注意， SSF_HIDEICONS = 0x00004000 = 16384≠fHideIcons = 4096 。如果 SSF _ 常数是与 SHELLSTATE 一起使用的掩码，则定义 SSF_HIDEICONS 作为2 ^ 14，当它是第13位（并且其掩码应该是2 ^ 12）在结构中。因此，看来，两个MSDN参考页面是相互矛盾的。

But before I tried the code, I noticed something very strange. I found that the constants I declared were already declared here: SSF Constants. Notice that SSF_HIDEICONS = 0x00004000 = 16384 ≠ fHideIcons = 4096. If the SSF_ constants really are masks used together with SHELLSTATE, then it makes no sense to define SSF_HIDEICONS as 2^14 when it is the 13th bit (and its mask should be 2^12) in the structure. Hence, it seems, the two MSDN reference pages contradict eachother.

有人可以把这一切清楚一些吗？

Could someone please bring some clarity into all this?

推荐答案

我的阅读帮助是在检索数据时为掩码指定了SSF_常数。没有理由必须映射到ShellState结构中的位。

My reading of the help here is that the SSF_ constants are specified for the mask when retrieving data. There's no reason they have to map to the bits in the ShellState structure.

如果他们做了fShowSysFiles将映射到8（0x04），并且从帮助中我们知道SSF_SHOWSYSFILES是0x20。没有直接映射。

If they did fShowSysFiles would map to 8 (0x04), and we know from the help that SSF_SHOWSYSFILES is 0x20. There's no direct mapping.

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