The following debugging tips will help you get the most out of your Visual Studio 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 on the statement to bring up the debugging context menu). Then, just step-in to 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 enabled by default, the settings are available in "Settings" of the project menu then Select "C/C++ tab. Select "General" from the "Category" group box. In the Debug info group box, select "Program Database for Edit and Continue.".
Unicode string display
Set your debugger options to display Unicode strings (Tools -> Options… -> Debug -> Display Unicode Strings check box).
Variable value display
Pause the cursor over a variable name in the source code to see its current value. If it is a structure, click it and bring up the QuickWatch dialog box (the Eyeglasses icon, or Shift-F9), or drag and drop it into the Watch window.
Undocking windows
If the Output window (or any docked window, for that matter) seems too small to you, try undocking it to make it a real window. Just right-click it and toggle the Docking View item.
Conditional breakpoints
Use conditional breakpoints when you need to stop at a breakpoint only once some condition is reached (a for-loop reaching a particular counter value). To do so, set the breakpoint normally, then bring up the Breakpoints window (Ctrl+B or Alt+F9). Select the specific breakpoint you just set and then click the Condition button to display a dialog in which you specify the breakpoint condition.
Preloading DLLs
You can preload DLLs that you want to debug before executing the program. This allows you to set breakpoints up front rather than wait until the DLL has been loaded during program execution. (Click Project > Settings > Debug > Category > Additional DLLs.) Then, click in the list area below to add any DLLs you wish to have preloaded.
Changing display formats
You can change the display format of variables in the QuickWatch dialog box or in the Watch window using the formatting symbols in the following table:
|
Symbol
|
Format
|
Value
|
Displays
|
|
d, i
|
signed decimal integer
|
0xF000F065
|
-268373915
|
|
u
|
unsigned decimal integer
|
0x0065
|
101
|
|
o
|
unsigned octal integer
|
0xF065
|
0170145
|
|
x, X
|
hexadecimal integer
|
61541
|
0x0000F065
|
|
l, h
|
long or short prefix for d, I, u, o, x, X
|
00406042, hx
|
0x0C22
|
|
f
|
signed floating-point
|
3./2.
|
1.500000
|
|
e
|
signed scientific notation
|
3./2.
|
1.500000e+00
|
|
g
|
e or f, whichever is shorter
|
3./2.
|
1.5
|
|
c
|
single character
|
0x0065
|
'e'
|
|
s
|
string
|
0x0012FDE8
|
"Hello"
|
|
su
|
Unicode string
|
0x0013ABE8
|
"Hello"
|
|
hr
|
string
|
0
|
S_OK
|
To use a formatting symbol, type the variable name followed by a comma and the appropriate symbol. For example, if var has a value of 0x0065, and you want to see the value in character form, type var,c in the Name column on the tab of the Watch window. When you press ENTER, the character-format value appears: var,c = 'e'. Likewise, assuming that hr is a variable holding HRESULTS, view a human-readable form of the HRESULT by typing "hr,hr" in the Name column.
You can use the formatting symbols shown in the following table to format the contents of memory locations:
|
Symbol
|
Format
|
Value
|
|
ma
|
64 ASCII characters
|
0x0012ffac
.4...0...".0W&.. .....1W&.0.:W..1 ...."..1.JO&.1.2 .."..1...0y....1 |
|
m
|
16 bytes in hex, followed by 16 ASCII characters
|
0x0012ffac
B3 34 CB 00 84 30 94 80 FF 22 8A 30 57 26 00 00 .4...0....".0W&.. |
|
mb
|
16 bytes in hex, followed by 16 ASCII characters
|
0x0012ffac
B3 34 CB 00 84 30 94 80 FF 22 8A 30 57 26 00 00 .4...0...".0W&.. |
|
mw
|
8 words
|
0x0012ffac
34B3 00CB 3084 8094 22FF 308A 2657 0000 |
|
md
|
4 double-words
|
0x0012ffac
00CB34B3 80943084 308A22FF 00002657 |
|
mu
|
2-byte characters (Unicode)
|
0x0012fc60
8478 77f4 ffff ffff 0000 0000 0000 0000 |
With the memory location formatting symbols, you can type any value or expression that evaluates to a location. To display the value of a character array as a string, precede the array name with an ampersand, &yourname. A formatting character can also follow an expression:
- rep+1,x
- alps[0],mb
- xloc,g
- count,d
To watch the value at an address or the value pointed to by a register, use the BY, WO, or DW operator:
- BY returns the contents of the byte pointed at.
- WO returns the contents of the word pointed at.
- DW returns the contents of the doubleword pointed at.
Follow the operator with a variable, register, or constant. If the BY, WO, or DW operator is followed by a variable, then the environment watches the byte, word, or doubleword at the address contained in the variable.
You can also use the context operator { } to display the contents of any location.
You can apply formatting symbols to structures, arrays, pointers, and objects as unexpanded variables only. If you expand the variable, the specified formatting affects all members. You cannot apply formatting symbols to individual members.
To display a Unicode string in the Watch window or the QuickWatch dialog box, use the su format specifier. To display data bytes with Unicode characters in the Watch window or the QuickWatch dialog box, use the mu format specifier.
Keyboard Shortcuts
There are numerous keyboard shortcuts that make working with the Visual Studio editor faster. Some of the more useful keyboard shortcuts are listed below.
The text editor uses many of the standard shortcut keys used by Windows applications like Word. Some specific source code editing short-cuts are listed in the table below:
|
Shortcut
|
Action
|
|
Alt+F8
|
Correct indentation of selected code based on surrounding lines.
|
|
Ctrl+]
|
Find the matching brace.
|
|
Ctrl+Alt+T
|
Display list of members.
|
|
Ctrl+Spacebar
|
Complete the word, once the number of letters entered allows the editor to recognize it. Useful when completing function and variable names.
|
|
Tab
|
Indents selection one tab stop to the right.
|
|
Shift+Tab
|
Indents selection one tab to the left.
|
Below is a table of common keyboard shortcuts used in the debugger:
|
Shortcut
|
Action
|
|
F9
|
Add or remove breakpoint from current line.
|
|
Ctrl+Shift+F9
|
Remove all breakpoints.
|
|
Ctrl+F9
|
Disable breakpoints.
|
|
Ctrl+Alt+A
|
Display auto window and move cursor into it.
|
|
Ctrl+Alt+C
|
Display call stack window and move cursor into it.
|
|
Ctrl+Alt+L
|
Display locals window and move cursor into it.
|
|
Shift+F5
|
End debugging session.
|
|
F11
|
Execute code one statement at a time, stepping into functions.
|
|
F10
|
Execute code one statement at a time, stepping over functions.
|
|
Ctrl+Shift+F5
|
Restart a debugging session.
|
|
Ctrl+F10
|
Resume the execution from current statement to selected statement.
|
|
F5
|
Run the application.
|
|
Ctrl+F5
|
Run the application without the debugger.
|
|
Ctrl+Shift+F10
|
Set the next statement.
|
|
Ctrl+Break
|
Stop execution.
|
Loading the shortcuts in the following table can greatly increase your productivity with the Visual Studio development environment:
|
Shortcut
|
Action
|
|
ESC
|
Close a menu or dialog box, cancel an operation in progress, or place focus in the current document window.
|
|
Ctrl+N
|
Create a new file.
|
|
Ctrl+F6 or Ctrl+Tab
|
Cycle through the MDI child windows one window at a time.
|
|
Ctrl+Alt+A
|
Display the auto window and move the cursor into it.
|
|
Ctrl+Alt+C
|
Display the call stack window and move the cursor into it.
|
|
Ctrl+H
|
Display the replace window.
|
|
Ctrl+F
|
Display the find window. If there is no current find criteria, but the word under your cursor in the find box.
|
|
Ctrl+Alt+I
|
Display the immediate window and move the cursor into it. o available if you are in the text editor window.
|
|
Ctrl+Alt+L
|
Display the locals window and move the cursor into it.
|
|
Ctrl+Alt+O
|
Display the output window and move the cursor into it.
|
|
Ctrl+Alt+J
|
Display the project explorer window and move the cursor into it.
|
|
Ctrl+Alt+P
|
Display the properties window and move the cursor into it.
|
|
Ctrl+Shift+O
|
Open a file.
|
|
Ctrl+O
|
Open a project.
|
|
Ctrl+P
|
Print all or part of the document.
|
|
Ctrl+Shift+S
|
Save all of the files, projects, and documents.
|
|
Ctrl+S
|
Select all.
|
|
Ctrl+A
|
Save the current document or selected item or items.
|
Navigating through online Help topics
Right-click a blank area of a toolbar to display a list of all the available toolbars. The Infoviewer toolbar contains up and down arrows that allow you to cycle through help topics in the order in which they appear in the table of contents. The left and right arrows cycle through help topics in the order that you visited them.