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Native Debugger Objects in NatVis

  • Article

Overview

Native debugger objects represent various constructs and behaviors of the debugger environment. Example debugger objects include the following.

  • Session
  • Threads / Thread
  • Processes / Process
  • Stack Frames / Stack Frame
  • Local Variables
  • Modules / Module
  • Utility
  • State
  • Settings

You can use the dx command and LINQ to interact with the debugger objects. For more information, see dx (Display Debugger Object Model Expression) and Using LINQ With the debugger objects.

You can also work with debugger objects using JavaScript. For more information about that see, Native Debugger Objects in JavaScript Extensions.

This topic describes how you can create custom NatVis visualizers to display debugger objects.

NatVis Development Resources

Refer to these resources for general information about working with NatVis.

Create custom views of native objects

.nvload

.nvlist

.nvunload

.nvunloadall

Custom NatVis object example

Create a simple C++ application that has an instance of the class CDog.

class CDog
{
public:
   CDog(){m_age = 8; m_weight = 30;}
   long m_age;
   long m_weight;
};

int main()
{
   CDog MyDog;
   printf_s("%d, %d\n", MyDog.m_age, MyDog.m_weight);
   return 0;
}

Create a file named Dog.natvis that contains this XML:

<?xml version="1.0" encoding="utf-8"?>
<AutoVisualizer xmlns="https://schemas.microsoft.com/vstudio/debugger/natvis/2010">
   <Type Name="CDog">
      <DisplayString>{{Age = {m_age} years. Weight = {m_weight} pounds.}}</DisplayString>
   </Type>
</AutoVisualizer>

Copy Dog.natvis to the Visualizers folder in your installation directory for Debugging Tools for Windows. For example:

C:\Program Files\Debugging Tools for Windows (x64)\Visualizers

Run your program, and break in at the main function. Take a step so that the variable MyDog gets initialized. Display MyDog using ?? and again using dx.

0:000> ??MyDog
class CDog
   +0x000 m_age        : 0n8
   +0x004 m_weight     : 0n30
0:000> *
0:000> dx -r1 MyDog
.....
MyDog     : {Age = 8 years. Weight = 30 pounds.} [Type: CDog]

See also

dx (Display Debugger Object Model Expression)

Using LINQ With the debugger objects

Native Debugger Objects in JavaScript Extensions