ch09.htm

delphi自学的好教材！特别适合刚刚起步学习delphi的人员！同样对使用者具有参考价值！

<P>The Debugging section of the Compiler page of the Project Options dialog box controls
how the compiler generates code for debugging sessions. When the Debug information
option is enabled, Delphi generates debug information for the project. If you do
not generate debug information, you will not be able to stop on breakpoints and inspect
variables during debugging. Put another way, you can't debug your program unless
you tell Delphi to generate debug information.</P>


<BLOCKQUOTE>
	<P>
<HR>
<strong>NOTE:</strong> If you change any of the options on the Compiler page, you should
	do a build immediately following the change. This will ensure that all units are
	rebuilt using the same compiler settings. 
<HR>


</BLOCKQUOTE>

<H4>Messages</H4>
<P>The Messages section determines whether you want the compiler to report hints
and warnings after compiling. I always leave both the Show Hints and Show Warnings
options on. Hints and warnings should not be ignored in the long term (in the short
term, you can ignore warnings that you know are due to temporary conditions in your
code). Usually, compiler warnings can, and should, be resolved. Learn to treat hints
and warnings as errors. Quality code compiles without warnings.</P>
<P>
<H3><A NAME="Heading11"></A>The Linker Page</H3>
<P>The Linker page of the Project Options dialog box is where you set options that
specify how you want the linker to operate. Until you become very familiar with Delphi,
you can leave this page alone and accept the default settings. Figure 9.6 shows the
Linker page of the Project Options dialog box. The options available on this page
are explained in the following sections.</P>
<P><A HREF="javascript:popUp('28670906.gif')"><B>FIGURE 9.6.</B></A><B> </B><I>Project
Linker options.</I></P>

<P><I></I>
<H4>Map File</H4>
<P>The Map File settings control whether a map file is generated and how much detail
is included in it. A map file is an advanced debugging tool and is something that
you will not likely use until you get further into Delphi. For that reason, I won't
go into more detail on the Map File options.</P>
<P>
<H4>EXE and DLL Options</H4>
<P>The EXE and DLL Options section determines the type of executable file produced
by Delphi for an application project. When the Generate Console Application check
box is checked, Delphi produces a console application as opposed to a GUI application.</P>
<P>The Include TD32 Debug Info option causes the linker to link the debug information
into the EXE or DLL. (&quot;TD32&quot; refers to the 32-bit version of the venerable
old Turbo Debugger. TD32 is an advanced standalone debugger that used to ship with
Borland C++ products and with some versions of Delphi.) Some debugging utilities
use debug information in TD32 format. TurboPower's Memory Sleuth, for example, requires
TD32 debug information to be present in the EXE. Turn this option on when using programs
like Memory Sleuth.</P>
<P>The Include Remote Debug Symbols option generates the debug symbols necessary
for remote debugging of Web broker applications.</P>
<P>
<H4>Linker Output</H4>
<P>The Linker Output section determines what type of compiled binary file the linker
should produce. Normally the linker produces DCU files (the default for Delphi applications).
You might, however, want to generate C or C++ object files (OBJs) rather than DCUs,
thereby allowing your Pascal units to be used with a C or C++ program built with
Borland C++Builder.</P>
<P>
<H4>Memory Sizes</H4>
<P>The Memory Sizes section can be ignored by all but the most advanced users. The
default values are acceptable for all applications. In some cases, you might change
the Image base address when building a DLL, but doing so is rarely necessary.</P>
<P>
<H4>Description</H4>
<P>The EXE Description field is used to specify a string that will be embedded in
the application. This field is sometimes used to add copyright information to an
EXE or DLL. Most of the time, you will use version info to store copyright information
in a file rather than using the EXE Description field on this page. Version info
is described later in the section &quot;The Version Info Page.&quot;</P>
<P>
<H3><A NAME="Heading12"></A>The Directories/Conditionals Page</H3>
<P>The Directories/Conditionals page of the Project Options dialog box is where you
set the directories that your project uses to find library files. Figure 9.7 shows
the Directories/ Conditionals page. The fields on this page are described in the
following sections.</P>
<P><A HREF="javascript:popUp('28670907.gif')"><B>FIGURE 9.7.</B></A><B> </B><I>The
Directories/ Conditionals page.</I></P>

<P><I></I>
<H4>Directories</H4>
<P>The fields in this section determine where Delphi can find various source files
during compilation of the project. It also contains fields that determine where certain
files created by the compiler and linker will be placed during a build of the project.</P>
<P>The Output Directory field is used to specify the directory where the final executable
file or DLL will be placed. The Unit Output Directory determines where the DCU files
will be placed for each unit compiled. The Search Path field is used to specify the
directories where any additional libraries needed to build the project can be found.
The Debug Source Path field is used to specify the path to any source units that
you want to debug, but which are not in the current project's directory. For example,
if you want to step into a DLL while debugging, you have to enter the path to the
DLL's source code in this field. The BPL Output Directory and the DCP Output Directory
fields specify where the BPL and DCP files should be placed when building a package.</P>
<P>Note that a small button with an ellipsis on it appears next to several of the
fields on the Directories/Conditionals page. Clicking this button displays an editor
that enables you to add, remove, or rearrange the items in a particular field. Figure
9.8 shows this dialog box while editing the Search Path field.</P>
<P><A HREF="javascript:popUp('28670908.gif')"><B>FIGURE 9.8.</B></A><B> </B><I>The
Directories editor dialog box.</I></P>

<P><I></I>
<H4>Conditionals</H4>
<P>You use the Conditional Defines field to specify any defines that you want to
add at the project level. For example, let's say you have code in your project that
will be compiled only if the symbol TRIALRUN is defined. In that case, you would
add TRIALRUN to the Conditional Defines field. If you have more than one symbol to
define, make sure that each symbol is separated by a semicolon.</P>
<P>
<H4>Aliases</H4>
<P>The Unit Aliases field is used to specify any unit aliases. For example, Delphi
1 used units called WinTypes.pas and WinProcs.pas for all Windows-specific code.
Delphi 2, 3, and 4 use a unit called Windows.pas in place of WinTypes and WinProcs.
The Unit Aliases field aliases WinTypes and WinProcs to the Windows unit. In this
case, aliasing enables programs written in Delphi 1 to compile in Delphi 4 without
modification of the uses list.</P>
<P>
<H3><A NAME="Heading13"></A>The Version Info Page</H3>
<P>The Version Info page enables you to set the version information for your applications.
Version information is stored in your program's EXE file or in a DLL or ActiveX file.
It is used by installation programs to determine whether a file being installed is
older or newer than the file it is replacing.</P>

<P>Version info has other uses as well. You can view the version information for
a file from Windows Explorer. Just right-click the file and choose Properties from
the Explorer context menu. When the Properties dialog box comes up, click the Version
tab to view the version information for the file. Figure 9.9 shows the Properties
dialog box displaying version information for the Database Desktop utility that comes
with Delphi.</P>

<P><A HREF="javascript:popUp('28670909.gif')"><B>FIGURE 9.9.</B></A><B> </B> <I>The
Properties dialog box showing version information for DBD32.EXE.</I></P>

<P>Figure 9.10 shows the Version Info page of the Project Options dialog box. At
the top of the page is a check box labeled Include Version Information in Project.
When this check box is checked, version information will be included in the project's
executable file. When this check box is not checked, version information is not included
in the project, and the rest of the page is disabled.</P>

<P><A HREF="javascript:popUp('28670910.gif')"><B>FIGURE 9.10.</B></A><B> </B><I>Version
information for your projects can be supplied on the Version Info page.</I></P>

<P>The remaining fields on the Version Info page are used to specify the various
pieces of version information. The Major Version, Minor Version, Release, and Build
fields work together to form the file version number. The version number of the file
in Figure 9.10 is version 2.0, build 0. If you check the Auto-Increment Build Number
option, the build number will automatically increment by one each time you perform
a build.</P>

<P>The Module Attributes section can be used to determine any special attributes
you want specified for the file. The Language section enables you to select a locale
identifier for the file. For more information on the possible values for the Locale
ID field, see the Windows API online help under the topic &quot;Language Identifiers
and Locales.&quot;</P>
<P>The table at the bottom of the Version Info page can be used to set a variety
of information. This information includes your company name, the file description,
the internal name of the file, the legal copyright or trademark information, the
product name, product version, and any comments you want to add.</P>
<P>You can provide information for any of these fields or none at all (the FileVersion
field is set based on the fields in the Module Version Number section). You can even
add your own custom version information fields. To add a custom version info field,
simply click in the version info table and scroll to the end of the table using the
down-arrow key. Type the down-arrow key once more and a dialog box will be displayed
asking you for the version key to add. Supply a key name and that key is added to
the version info for the project. Adding version information to a project has never
been so easy!</P>
<P>
<H3><A NAME="Heading14"></A>The Packages Page</H3>
<P>The Packages page is where you determine the type of linking that your projects
will use. The top part of the page enables you to add or remove design packages,
but that really doesn't have anything to do with the current project. The only option
that pertains to the current project is the Build with Runtime Packages check box.</P>
<P>When this option is selected, your application will use dynamic linking of the
VCL and any third-party components. This means that your executable file will be
smaller, but you will have to be sure to ship the correct packages with your application.
When this check box is off, your application uses static linking. <I>Static linking</I>
means that any VCL code and the code from any third-party components that your application
uses is linked directly into your executable file. Packages were discussed in detail
yesterday in the section &quot;Using Packages.&quot; Figure 9.11 shows the Packages
page of the Project Options dialog box.</P>
<P><A HREF="javascript:popUp('28670911.gif')"><B>FIGURE 9.11.</B></A><B> </B><I>The
Packages page.</I></P>

<P><I></I>
<H2><A NAME="Heading15"></A>The Delphi Code Editor</H2>
<P>There is no question that Delphi is highly visual in nature--that's one of the
great benefits of programming with Delphi. Still, any program of any significance
will have a great deal of code that must be written by hand. After you get the UI
part of your application written with Delphi's impressive visual tools, you'll likely
spend a long stretch with the Delphi Code Editor. The Code Editor has some features
you'll learn to appreciate when you discover them.</P>
<P>In this section, you learn about the following:</P>

<UL>
	<LI>Basic editor operations
	<P>
	<LI>Specialized editor features
	<P>
	<LI>The Code Editor context menu
	<P>
	<LI>Changing the editor options
</UL>



<BLOCKQUOTE>
	<P>
<HR>
<strong>NOTE:</strong> The Delphi Code Editor enables you to choose from four keyboard-mapping
	configurations: Default, IDE Classic, BRIEF, and Epsilon. The rest of this chapter
	assumes Default keyboard mapping. If you are already familiar with one of the other
	keyboard mapping configurations, you can ignore any references to specific keystrokes.
	
<HR>


</BLOCKQUOTE>

<H3><A NAME="Heading16"></A>Basic Editor Operations</H3>
<P>I'm going to assume that you know enough to be able to enter and delete text,
highlight text with the mouse, cut, copy, paste, and so on. I won't spend any time
going over functions at that level.</P>
<P>When it comes right down to it, the Delphi Code Editor is a typical code editor.
It features syntax highlighting, which makes identifying keywords, strings, numeric
constants, and comments at a glance easy. You'll look at setting the editor preferences
a little later.</P>
<P>The Code Editor is a tabbed window. You can open as many editor windows as you
like; each window will be represented by a tab along the top of the editor window
that will display the name of the file. To switch to a source file, simply click
the tab corresponding to the file you want to view. If more tabs exist than can be
displayed at one time, scroll buttons will appear so that you can scroll among the
tabs.</P>
<P>The status bar at the bottom of the Code Editor gives status information (obviously).
The current line number and the cursor position on the line are reported in the left
panel of the status bar. If the file has changed since it was last saved, the status
bar will say Modified in the center panel of the status bar. The right panel of the
status bar shows the current mode, either Insert or Overwrite. If the file has been
set to read-only, this panel will say Read Only.</P>
<P>The editor window has a gray strip in the left margin that is called the <I>gutter</I>.
The gutter is used to display icons at different stages of the development process.
For example, when you set a debugger breakpoint (discussed tomorrow), a red dot is
placed in the gutter. When you set a bookmark (discussed in just a bit), an icon
representing the bookmark is placed in the gutter.</P>


<BLOCKQUOTE>
	<P>
<HR>
<strong>NOTE:</strong> If you accidentally click on the gutter when trying to select text
	or place the cursor, you will find that a breakpoint is set on that line. Click the
	gutter again to clear the breakpoint. 
<HR>


</BLOCKQUOTE>

<H4>Opening and Saving Files</H4>
<P>Nothing is very mysterious about opening and saving files in the Code Editor.
It should be pointed out, though, that there is a difference between opening a project
and opening a source file. When you choose File|Open Project from the main menu,
you are prompted for the name of a project file to open. When you choose File|Open
from the main menu, you can open an individual Delphi source file or form file. Actually,
you can open any type of text file (including file types not listed in the Open dialog
box's Files of Type field). This includes .pas, .rc, .txt, and even C++ source and
header files (.cpp and .h). Both the Open and Open Project menu items have corresponding
toolbar buttons.</P>


<BLOCKQUOTE>
	<P>
<HR>
<strong>NOTE:</strong> If you open a unit file (.pas) that contains a form, Delphi will
	open the source file in the Code Editor and will also open the form in the Form Designer.