MSDN Documentation

Visual Studio Debugger

The Visual Studio Debugger is a powerful tool for debugging applications developed in Visual Studio. It allows you to step through code, inspect variables, set breakpoints, and analyze program execution to identify and resolve issues.

Key Features

  • Breakpoints: Set conditional or unconditional breakpoints to pause execution at specific lines of code.
  • Stepping: Control execution flow with commands like Step Into, Step Over, and Step Out.
  • Watch Windows: Monitor the values of variables and expressions in real-time.
  • Call Stack: View the sequence of function calls that led to the current execution point.
  • Immediate Window: Evaluate expressions and execute code snippets during a debugging session.
  • Disassembly Window: Examine the generated machine code for your application.
  • Memory and Register Views: Inspect the contents of memory and CPU registers.
  • Tracepoints: Log messages without breaking execution.
  • Edit and Continue: Modify code while debugging and see the changes reflected immediately.

Getting Started

To begin debugging:

  1. Open your project in Visual Studio.
  2. Set breakpoints by clicking in the margin next to the line of code where you want execution to pause.
  3. Press F5 or click the Start Debugging button to run your application.
  4. When a breakpoint is hit, the debugger will pause execution, and you can use the debugging windows to inspect your program's state.

Common Debugging Scenarios

Null Reference Exceptions

If you encounter a NullReferenceException, use the Watch or Autos windows to check if the object you are trying to access is null. You can also set conditional breakpoints that trigger only when a specific variable is null.

Performance Issues

For performance bottlenecks, consider using the Visual Studio Profiler or Performance Analyzer. These tools can help identify CPU usage, memory allocations, and other performance-critical areas.

Advanced Debugging Techniques

Conditional Breakpoints

Right-click on a breakpoint and select "Conditions" to specify an expression that must evaluate to true for the breakpoint to be triggered.

myVariable > 10

Tracepoints

Tracepoints allow you to log information to the Output window without interrupting program execution. Right-click a breakpoint and choose "Actions" to configure a tracepoint message.

"Current value of counter: " + counter

Using the Immediate Window

The Immediate Window is invaluable for testing code snippets or checking variable values. You can type C# or C++ expressions directly into it.

? myObject.SomeProperty
myVariable = 5;

Further Reading