ArcGIS Engine Developer Guide

VISUAL C++
Here are some suggestions for a naming
convention. These help identify the variables’
usage and type and so reduce coding errors. This
is an abridged Hungarian notation:
Prefix
m
c
g
Prefix
b
by
cx/cy
d
dw
f
fn
h
i
ip
l
p
s
sz
w
x, y
[_]
Variable scope
Instance class members
Static class member (including constants)
Globally static variable
local variable or struct or public class
member
Data Type
Boolean
byte or unsigned char
short used as size
double
DWORD, double word or unsigned long
float
function
handle
int (integer)
smart pointer
long
a pointer
string
ASCIIZ null-terminated string
WORD unsigned int
short used as coordinates
describes how the variable is used or
what it contains. The and
portions should always be lowercase, and the
should use mixed case:
• For state functions, use Set and Is or Can:
bool IsFileDirty();
void SetFileDirty(bool dirty);
bool CanConnect();
• Where the semantics of an operation are obvious from the types of arguments,
leave type names out of the function names.
Instead of:
AddDatabase(Database& db);
consider using:
Add(Database& db);
Instead of:
ConvertFoo2Bar(Foo* foo, Bar* bar);
consider using:
Convert(Foo* foo, Bar* bar)
• If a client relinquishes ownership of some data to an object, use
Give. If an object relinquishes ownership of some data to a
client, use Take:
void GiveGraphic(Graphic* graphic);
Graphic* TakeGraphic(int itemNum);
• Use function overloading when a particular operation works with different
argument types:
void Append(const CString& text);
void Append(int number);
Argument names
Use descriptive argument names in function declarations. The argument name
should clearly indicate what purpose the argument serves:
bool Send(int messageID, const char* address, const char* message);
Variable Name
m_hWnd
ipEnvelope
m_pUnkOuter
c_isLoaded
g_pWindowList
Description
a handle to HWND
a smart pointer to a COM interface
a pointer to an object
a static class member
a global pointer to an object
DEBUGGING TIPS IN DEVELOPER STUDIO
Visual C++ comes with a feature-rich debugger. These tips will help you get the
most from your debugging session.
Backing up after failure
When a function call has failed and you’d like to know why (by stepping into
it), you don’t have to restart the application. Use the Set Next Statement
command to reposition the program cursor back to the statement that failed
(right-click the statement to bring up the debugging context menu). Then step
into the function.
Edit and Continue
Visual Studio 6 allows changes to source code to be made during a debugging
session. The changes can be recompiled and incorporated into the executing code
without stopping the debugger. There are some limitations to the type of changes
that can be made; in this case, the debug session must be restarted. This feature is
116 • ArcGIS Engine Developer Guide