Revit Automation and API Programming Guide

Introduction to Revit Automation

Revit automation through the API (Application Programming Interface) allows AEC professionals to streamline repetitive tasks, enforce standards, and create custom workflows that extend Revit's native capabilities. This guide provides a comprehensive introduction to Revit API programming with practical examples in both C# and Python.

Getting Started with the Revit API

Before diving into specific automation examples, it's important to understand the structure and capabilities of the Revit API:

API Documentation: Accessing and navigating the Revit API documentation
Development Environment Setup: Configuring Visual Studio and Python environments
Basic Concepts: Understanding the Revit API object model, transactions, and event handling
Add-in Development: Creating external commands and applications

C# Examples for Revit Automation

C# is the primary language for Revit API development. Here are key examples covered in this guide:

1. Element Selection and Filtering

C# Example

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                                        // Get all walls in the current document
FilteredElementCollector collector = new FilteredElementCollector(doc);
ICollection<Element> walls = collector.OfClass(typeof(Wall)).ToElements();

// Filter walls by parameter value
List<Element> filteredWalls = new List<Element>();
foreach (Element wall in walls)
{
    Parameter param = wall.LookupParameter("Comments");
    if (param != null && param.AsString() == "Exterior")
    {
        filteredWalls.Add(wall);
    }
}

2. Parameter Management

C# Example

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                                        // Set parameter value for multiple elements
using (Transaction tx = new Transaction(doc, "Set Parameters"))
{
    tx.Start();
    foreach (Element element in elements)
    {
        Parameter param = element.LookupParameter("Mark");
        if (param != null && !param.IsReadOnly)
        {
            param.Set("New Value");
        }
    }
    tx.Commit();
}

3. Geometry Creation

C# Example

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                                        // Create a wall by curve
using (Transaction tx = new Transaction(doc, "Create Wall"))
{
    tx.Start();
    
    // Create a line for the wall path
    XYZ start = new XYZ(0, 0, 0);
    XYZ end = new XYZ(20, 0, 0);
    Line line = Line.CreateBound(start, end);
    
    // Get wall type and level
    WallType wallType = new FilteredElementCollector(doc)
        .OfClass(typeof(WallType)).FirstElement() as WallType;
    Level level = new FilteredElementCollector(doc)
        .OfClass(typeof(Level)).FirstElement() as Level;
    
    // Create the wall
    Wall.Create(doc, line, wallType.Id, level.Id, 10, 0, false, false);
    
    tx.Commit();
}

Python Examples for Revit Automation

Python offers a more accessible entry point for many users. This guide covers Python scripting through pyRevit and the RevitPythonShell:

1. Element Selection with Python

Python Example

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                                        # Get all doors in the current document
from Autodesk.Revit.DB import FilteredElementCollector, FamilyInstance, BuiltInCategory
from Autodesk.Revit.UI import TaskDialog

doc = __revit__.ActiveUIDocument.Document
doors = FilteredElementCollector(doc).OfCategory(BuiltInCategory.OST_Doors).WhereElementIsNotElementType().ToElements()

# Display count of doors
TaskDialog.Show("Door Count", "Number of doors: {}".format(len(doors)))

2. Working with Parameters in Python

Python Example

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                                        # Get and modify parameters
from Autodesk.Revit.DB import Transaction

doc = __revit__.ActiveUIDocument.Document
uidoc = __revit__.ActiveUIDocument

# Start a transaction
t = Transaction(doc, "Modify Parameters")
t.Start()

# Get selected elements
selection = [doc.GetElement(id) for id in uidoc.Selection.GetElementIds()]

for element in selection:
    # Try to get the Comments parameter
    param = element.LookupParameter("Comments")
    if param and not param.IsReadOnly:
        param.Set("Modified by Python script")

t.Commit()

Advanced Automation Techniques

Beyond basic API usage, this guide covers advanced automation techniques:

Dynamo Integration: Combining visual programming with API scripts
Batch Processing: Processing multiple files and elements
Database Integration: Connecting Revit to external databases
UI Development: Creating custom interfaces for your tools
Deployment: Distributing tools to team members

Practical Automation Workflows

The guide includes complete workflows for common automation scenarios:

Drawing Sheet Setup: Automating the creation of drawing sheets and views
Model Auditing: Checking models against standards and generating reports
Data Exchange: Exporting and importing data between Revit and other platforms
Documentation: Automating annotation and dimensioning
Design Automation: Generating design options based on parameters

Best Practices and Performance Optimization

Successful Revit automation requires attention to performance and reliability:

Transaction Management: Optimizing transaction usage for performance
Error Handling: Implementing robust error handling and logging
Performance Techniques: Methods to improve execution speed
Version Compatibility: Ensuring add-ins work across Revit versions
Testing Strategies: Approaches for testing automation tools

Introduction to Revit Automation

Getting Started with the Revit API

Before diving into specific automation examples, it's important to understand the structure and capabilities of the Revit API:

API Documentation: Accessing and navigating the Revit API documentation
Development Environment Setup: Configuring Visual Studio and Python environments
Basic Concepts: Understanding the Revit API object model, transactions, and event handling
Add-in Development: Creating external commands and applications

C# Examples for Revit Automation

C# is the primary language for Revit API development. Here are key examples covered in this guide:

1. Element Selection and Filtering

C# Example

                                        1
2
3
4
5
6
7
8
9
10
11
12
                                        // Get all walls in the current document
FilteredElementCollector collector = new FilteredElementCollector(doc);
ICollection<Element> walls = collector.OfClass(typeof(Wall)).ToElements();

// Filter walls by parameter value
List<Element> filteredWalls = new List<Element>();
foreach (Element wall in walls)
{
    Parameter param = wall.LookupParameter("Comments");
    if (param != null && param.AsString() == "Exterior")
    {
        filteredWalls.Add(wall);
    }
}

2. Parameter Management

C# Example

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                                        // Set parameter value for multiple elements
using (Transaction tx = new Transaction(doc, "Set Parameters"))
{
    tx.Start();
    foreach (Element element in elements)
    {
        Parameter param = element.LookupParameter("Mark");
        if (param != null && !param.IsReadOnly)
        {
            param.Set("New Value");
        }
    }
    tx.Commit();
}

3. Geometry Creation

C# Example

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                                        // Create a wall by curve
using (Transaction tx = new Transaction(doc, "Create Wall"))
{
    tx.Start();
    
    // Create a line for the wall path
    XYZ start = new XYZ(0, 0, 0);
    XYZ end = new XYZ(20, 0, 0);
    Line line = Line.CreateBound(start, end);
    
    // Get wall type and level
    WallType wallType = new FilteredElementCollector(doc)
        .OfClass(typeof(WallType)).FirstElement() as WallType;
    Level level = new FilteredElementCollector(doc)
        .OfClass(typeof(Level)).FirstElement() as Level;
    
    // Create the wall
    Wall.Create(doc, line, wallType.Id, level.Id, 10, 0, false, false);
    
    tx.Commit();
}

Python Examples for Revit Automation

Python offers a more accessible entry point for many users. This guide covers Python scripting through pyRevit and the RevitPythonShell:

1. Element Selection with Python

Python Example

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                                        # Get all doors in the current document
from Autodesk.Revit.DB import FilteredElementCollector, FamilyInstance, BuiltInCategory
from Autodesk.Revit.UI import TaskDialog

doc = __revit__.ActiveUIDocument.Document
doors = FilteredElementCollector(doc).OfCategory(BuiltInCategory.OST_Doors).WhereElementIsNotElementType().ToElements()

# Display count of doors
TaskDialog.Show("Door Count", "Number of doors: {}".format(len(doors)))

2. Working with Parameters in Python

Python Example

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                                        # Get and modify parameters
from Autodesk.Revit.DB import Transaction

doc = __revit__.ActiveUIDocument.Document
uidoc = __revit__.ActiveUIDocument

# Start a transaction
t = Transaction(doc, "Modify Parameters")
t.Start()

# Get selected elements
selection = [doc.GetElement(id) for id in uidoc.Selection.GetElementIds()]

for element in selection:
    # Try to get the Comments parameter
    param = element.LookupParameter("Comments")
    if param and not param.IsReadOnly:
        param.Set("Modified by Python script")

t.Commit()

Advanced Automation Techniques

Beyond basic API usage, this guide covers advanced automation techniques:

Dynamo Integration: Combining visual programming with API scripts
Batch Processing: Processing multiple files and elements
Database Integration: Connecting Revit to external databases
UI Development: Creating custom interfaces for your tools
Deployment: Distributing tools to team members

Practical Automation Workflows

The guide includes complete workflows for common automation scenarios:

Drawing Sheet Setup: Automating the creation of drawing sheets and views
Model Auditing: Checking models against standards and generating reports
Data Exchange: Exporting and importing data between Revit and other platforms
Documentation: Automating annotation and dimensioning
Design Automation: Generating design options based on parameters

Best Practices and Performance Optimization

Successful Revit automation requires attention to performance and reliability:

Transaction Management: Optimizing transaction usage for performance
Error Handling: Implementing robust error handling and logging
Performance Techniques: Methods to improve execution speed
Version Compatibility: Ensuring add-ins work across Revit versions
Testing Strategies: Approaches for testing automation tools

Revit Automation and API Programming Guide

Table of Contents

Request

Introduction to Revit Automation

Getting Started with the Revit API

C# Examples for Revit Automation

1. Element Selection and Filtering

2. Parameter Management

3. Geometry Creation

Python Examples for Revit Automation

1. Element Selection with Python

2. Working with Parameters in Python

Advanced Automation Techniques

Practical Automation Workflows

Best Practices and Performance Optimization

Request

Revit Automation Code Examples

Notes

Tips

Warnings

Request resource

Try It Yourself

Related Resources

Advanced BIM Coordination Techniques

Introduction to Parametric Design in Revit

Revit Automation and API Programming Guide

Table of Contents

Request

Introduction to Revit Automation

Getting Started with the Revit API

C# Examples for Revit Automation

1. Element Selection and Filtering

2. Parameter Management

3. Geometry Creation

Python Examples for Revit Automation

1. Element Selection with Python

2. Working with Parameters in Python

Advanced Automation Techniques

Practical Automation Workflows

Best Practices and Performance Optimization

Request

Revit Automation Code Examples

Notes

Tips

Warnings

Request resource

Try It Yourself

Related Resources

Advanced BIM Coordination Techniques

Introduction to Parametric Design in Revit