1 导言
在软件开发周期中,测试和修正缺陷(defect,defect与bug的区别:Bug是缺陷的一种表现形式,而一个缺陷是可以引起多种Bug的) 的时间远多于写代码的时间。通常,debug是指发现缺陷并改正的过程。修正缺陷紧随debug之后,或者说二者是相关的。如果代码中存在缺陷,我们首先 要识别造成缺陷的根本原因(root cause),这个过程就称作调试(debugging)。找到根本原因后,就可以修正缺陷。
那么如何调试代码呢?Visual Studio提供了很多用于调试的工具。有时调试需要花费大量时间去识别root cause。VS提供了许多辅助调试的便捷的工具。调试器(Debugger)包含错误列表、添加断点、可视化的程序流程、控制执行流程、Data Tips、监视窗口(watch windows)、多线程调试、线程窗口、并行调试概览以及IntelliTrace调试概览。我希望本文能够对调试功能的使用者有所裨益。请注意,本文 使用VS2010。某些功能在旧版本中也是一致的,但是VS2010新增了许多features(Labeling breakpoint, Pinned DataTip, Multithreaded Debugging, Parallel debugging and IntelliTrace)。
2 如何启动调试?
图 启动调试(Start Debugging)
“附加到进程(Attach to Process)”是另一种启动调试的方法。Attach Process会为应用程序启动一个调试会话。可能我们更熟悉ASP.NET Web应用的Attach Process调试。我发了另外两篇相关的帖子。如下:
- Debug Your ASP.NET Application that Hosted on IIS
- Remote IIS Debugging: Debug your ASP.NET Application which is hosted on "Remote IIS Server"
通常我们通过在可能存在问题代码处加断点来启动调试。因此,我们从断点开始讲起。
3 断点(Breakpoints)
图 设置断点(Set Breakpoint)
3.1 使用断点进行调试
在中断模式下,你有多条可使用的命令,使用相应命令进行进一步的调试。
图 断点工具条(Breakpoint Toolbar)
3.1.1 逐过程(Step Over)
3.1.2 逐语句(Step Into)
3.1.3 跳出(Step Out)
3.1.4 继续(Continue)
3.1.5 设置下一语句(Set Next Statement)
3.1.6 显示下一语句(Show Next Statement [Ctrl+*])
3.2 断点标签(Labeling in Break Point)
- class Program
- {
- static void Main(string[] args)
- {
- string[] strNames = { "Name1", "Name2", "Name3", "Name4", "Name5", "Name6" };
- foreach (string name in strNames)
- {
- Console.WriteLine(name); // BreakPoint
- }
- int temp = 4;
- for (int i = 1; i <= 10; i++)
- {
- if (i > 6)
- temp = 5;
- }
- }
- public static void Method1()
- {
- Console.WriteLine("Break Point in Method1"); // BreakPoint
- }
- public static void Method2()
- {
- Console.WriteLine("Break Point in Method2"); // BreakPoint
- Console.WriteLine("Break Point in Method2"); // BreakPoint
- }
- public static void Method3()
- {
- Console.WriteLine("Break Point in Method3"); // Breakpoint
- }
- }
3.3 条件断点(Conditional Breakpoint)
- class Program
- {
- static void Main(string[] args)
- {
- string [] strNames = { "Name1","Name2", "Name3", "Name4", "Name5", "Name6"};
- foreach(string name in strNames)
- {
- Console.WriteLine(name); // Breakpoint is here
- }
- }
- }
- Is True
- Has Changed
3.4 导入/导出断点(Import / Export Breakpoint)
3.5 断点命中计数(Breakpoint Hit Count)
3.6 Breakpoint When Hit
3.7 断点筛选器(Breakpoint Filter)
4 数据便签(Data Tip)
4.1 Pin Inspect Value During Debugging
4.2 Drag-Drop Pin Data Tip
4.3 Adding Comments
4.4 Last Session Debugging Value
4.5 Import Export Data Tips
4.6 Change Value Using Data Tips
4.7 Clear Data Tips
5 监视窗口(Watch Windows)
5.1 局部变量(Locals)
5.2 自动窗口(Autos)
5.3 监视(Watch)
有4个可同时使用的监视窗口。
图:多个监视窗口
5.3.1 Creating Object ID
5.4
6 即时窗口(Immediate Window)
7 调用堆栈(Call Stack)
8 调试多线程程序(Debugging Multithreaded Program)
8.1 Exploring Threads Window
8.2 Flag Just My Code
8.3 Break Point Filter - Multithread Debugging
9 调试并行程序(Debugging Parallel Program)
9.1 Parallel Task and Parallel Stacks
10 Debugging with IntelliTrace
10.1 Overview
10.2 Mapping with IntelliTrace
10.3 Filter IntelliTrace Data
11 调试常用快捷键(Useful Shortcut Keys For VS Debugging)
Shortcut Keys | Descriptions |
Ctrl-Alt-V, A | Displays the Auto window |
Ctrl-Alt-B | Displays the Breakpoints dialog |
Ctrl-Alt-C | Displays the Call Stack |
Ctrl-Shift-F9 | Clears all of the breakpoints in the project |
Ctrl-F9 | Enables or disables the breakpoint on the current line of code |
Ctrl-Alt-E | Displays the Exceptions dialog |
Ctrl-Alt-I | Displays the Immediate window |
Ctrl-Alt-V, L | Displays the Locals window |
Ctrl-Alt-Q | Displays the Quick Watch dialog |
Ctrl-Shift-F5 | Terminates the current debugging session, rebuilds if necessary, and starts a new debugging session. |
Ctrl-F10 | Starts or resumes execution of your code and then halts execution when it reaches the selected statement. |
Ctrl-Shift-F10 | Sets the execution point to the line of code you choose |
Alt-NUM * | Highlights the next statement |
F5 | If not currently debugging, this runs the startup project or projects and attaches the debugger. |
Ctrl-F5 | Runs the code without invoking the debugger |
F11 | Step Into |
Shift-F11 | Executes the remaining lines out from procedure |
F10 | Executes the next line of code but does not step into any function calls |
Shift-F5 | Available in break and run modes, this terminates the debugging session |
Ctrl-Alt-H | Displays the Threads window to view all of the threads for the current process |
F9 | Sets or removes a breakpoint at the current line |
Ctrl-Alt-W, 1 | Displays the Watch 1 window to view the values of variables or watch expressions |
Ctrl-Alt-P | Displays the Processes dialog, which allows you to attach or detach the debugger to one or more running processes |
Ctrl-D,V | IntelliTrace Event |
12 深入学习(Further Study)
13 总结(Summary)
“自动窗口”(Autos):当前使用的变量
“局部窗口”(Locals):在范围内的所有变量
“监视N”(Watch):可定制(N从1到4)
Step Into(逐语句):执行并移动到下一条语句(实际上,跳入上一条语句的代码块,此代码块的第一条)
Step Over(逐过程):执行并跳到下一条语句,但不进入上一条语句的代码块
Step Out(跳出):执行到代码块结尾
命令窗口(Command)
即时窗口(Immediate):主要用于计算表达式
参考资料:
[1] Mastering Debugging in Visual Studio 2010 - A Beginner's Guide
[2] bug和缺陷的区别