Showing tag results for Code

Aug 31, 2004
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Reading a contract from the other side: Application publishers

Raymond Chen
Raymond Chen

In an earlier article, I gave an example of reading a contract from the other side. Here's another example of how you can read a specification and play the role of the operating system. I chose this particular example because somebody wanted to do this and didn't realize that everything they needed was already documented; they just needed to look...

Code
Aug 26, 2004
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Why do some structures end with an array of size 1?

Raymond Chen
Raymond Chen

Some Windows structures are variable-sized, beginning with a fixed header, followed by a variable-sized array. When these structures are declared, they often declare an array of size 1 where the variable-sized array should be. For example: typedef struct _TOKEN_GROUPS { DWORD GroupCount; SID_AND_ATTRIBUTES Groups[ANYSIZE_ARRAY]; } TOKEN...

Code
Aug 25, 2004
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Why can’t you treat a FILETIME as an __int64?

Raymond Chen
Raymond Chen

The FILETIME structure represents a 64-bit value in two parts: typedef struct _FILETIME { DWORD dwLowDateTime; DWORD dwHighDateTime; } FILETIME, *PFILETIME; You may be tempted to take the entire FILETIME structure and access it directly as if it were an __int64. After all, its memory layout exactly matches that of a 64-bit (little-endian)...

CodeTime
Aug 24, 2004
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Beware of non-null-terminated registry strings

Raymond Chen
Raymond Chen

Even though a value is stored in the registry as REG_SZ, this doesn't mean that the value actually ends with a proper null terminator. At the bottom, the registry is just a hierarchically-organized name/value database. And you can lie and get away with it. Lots of people lie about their registry data. You'll find lots of things that should be...

Code
Aug 20, 2004
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Writing your own menu-like window

Raymond Chen
Raymond Chen

Hereby incorporating by reference the "FakeMenu" sample in the Platform SDK. It's in the winui\shell\fakemenu directory. For those who don't have the Platform SDK, what are you doing writing Win32 programs without the Platform SDK? Download it if it didn't come with your development tools. If for some reason you don't want the Platform SDK yet ...

Code
Aug 4, 2004
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Never leave focus on a disabled control

Raymond Chen
Raymond Chen

One of the big no-no's in dialog box management is disabling the control that has focus without first moving focus somewhere else. When you do this, the keyboard becomes dead to the dialog box, since disabled windows do not receive input. For users who don't have a mouse (say, because they have physical limitations that confine them to the keyboar...

Code
Aug 4, 2004
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Why .shared sections are a security hole

Raymond Chen
Raymond Chen

Many people will recommend using shared data sections as a way to share data between multiple instances of an application. This sounds like a great idea, but in fact it's a security hole. Proper shared memory objects created by the CreateFileMapping function can be secured. They have security descriptors that let you specify which users are all...

Code
Aug 2, 2004
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How to set focus in a dialog box

Raymond Chen
Raymond Chen

Setting focus in a dialog box is more than just calling SetFocus. A dialog box maintains the concept of a "default button" (which is always a pushbutton). The default button is typically drawn with a distinctive look (a heavy outline or a different color) and indicates what action the dialog box will take when you hit Enter. Note that this is no...

Code
Jul 29, 2004
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When should you use a sunken client area?

Raymond Chen
Raymond Chen

The WS_EX_CLIENTEDGE extended window style allows you to create a window whose client area is "sunken". When should you use this style? The Guidelines for User Interface Developers and Designers says in the section on the Design of Visual Elements that the sunken border should be used "to define the work area within a window". Spec...

Code