How To Replace Multilines in Visual Studio

Overview of Multiline Editing in Visual Studio

Visual Studio provides extensive support for editing across line breaks:

• Find and replace literals, wildcards, and regular expressions spanning multiple lines.
• Scope multiline searches to selected text, documents, projects, or entire solutions.
• Leverage .NET regex syntax for complex multilined find patterns.
• Use special backslash escapes to match line breaks in regex replacements.
• Inspect search results and selectively apply replacements.
• Support for multiline editing across VS languages like C#, JavaScript, Python, and more.

These multilined editing capabilities help tackle wide-ranging codebase refactors with ease.

Why Multiline Editing Matters

Robust multiline find-and-replace delivers important benefits:

• Make codebase-wide variable and method renames safe and fast.
• Standardize formatting by changing multiline comment styles.
• Modify complex multi-statement logic by searching brackets and braces.
• Fix invalid string literals spanning lines.
• Reflow text by altering line breaks.
• Quickly implement standard style guidelines and conventions.
• Accurately update licenses, copyright notices, and shared text blocks.

Overall, multiline editing is invaluable for large-scale codebase manipulation.

Using Multiline Selection for Focused Finds

Visual Studio offers multiline selection for focusing finds:

Enable Mulitline Selection

Enable with Edit > Advanced > View Whitepsace:

This shows special glyphs for line breaks.

Make a Multiline Selection

Highlight across multiple lines:

Use arrows with Shift or drag with mouse.

Find Within Selection

Search for matches only within the selection:

This narrows scope to selected text.

Multiline selecting avoids overbroad changes across code.

Finding Multiline Literals

Find literal strings spanning lines with:

Wildcards

Use asterisks * to match anything:

Find: Hello*world
Matches:
Hello
world

Helloeveryone
world

Caret ^ for Line Starts

Use ^ to require line start matching:

Find: ^Hello*world
Matches: 

Hello
world

Doesn't match:
ByeHello
world 

Dollar $ for Line End

Use $ to require line end matching:

Find: Hello*world$
Matches:

Hello
world

Doesn't match: 
Hello
world!

With these wildcards, flexible literal multiline finds are possible.

Finding with .NET RegexMultiline Expressions

For complex finds, use .NET regex multiline mode:

Regex Multiline Flag

Enable with (?m) flag:

Find: (?m)Hello.*world

This allows ^, $, and . to match line breaks.

Start and End Anchors

Use \A and \Z to anchor multiline matches:

Find: \AHello.*\Z
Matches: 

Hello 
world

But not:

Bye 
Hello
world

Dotall Mode

Set (?s) flag so dot . matches line breaks:

Find: (?s)Hello.*world

This matches any character including newlines.

Word Boundaries

Use \b in multiline mode to match word breaks:

Find: (?m)\bworld\b

Matches ‘world’ surrounded by word breaks.

Regex enables extremely flexible multiline finds.

Multiline Replacements with Regex Backslashes

Special regex escapes insert newlines and literal replacements:

Newline Escape

\r and \n insert newlines

Replace: Hello \\r\\n world

Becomes:
Hello
world

Carriage Return

\r for carriage returns

Literal Backslashes

\\ to insert literal backslashes

Other Regex Metacharacters

Escape regex symbols with \

Backslash handling enables inserting multiline text.

Multiline Find and Replace Scope Options

Scope multiline operations to:

Selected Text

Just act within the current text selection.

Current Document

Apply to only the active document.

All Open Documents

Span every open document.

Current Project

Apply changes across the whole project.

Entire Solution

Replace globally across all projects.

Scope avoids accidentally impacting unrelated code.

Reviewing Multiline Find Results

Review results before applying replacements:

Preview Files

Inspect changed files with the right arrow icon:

Review diffs visually.

Open Files

Double click result lines to open files.

Selective Replacement

Uncheck unwanted result lines to skip them.

Undo Support

Revert unwanted replacements.

Thorough reviewing prevents overbroad find-and-replace mistakes.

Example Multiline Refactors in Visual Studio

Some examples of useful multiline refactors:

Changing Multiline Comments

Easily update comment styles:

/* Old
block comment */

Regex replace:
/*.**/

With:
// New
line comment

This converts comment formats.

Method Renaming

Rename methods across classes:

void oldMethod() {

}

Regex replace: 
(?m)oldMethod\(\)

With:
newMethod()

This safely renames globally.

String Literal Formatting

Standardize string formats spanning lines:

"Old string 
literal"

Replace:
"(?m)"".*""

With: 
@"New verbatim 
string literal"

Powerful for formatting fixes.

Variable Renames

Change variables globally:

old_variable = 1;

Replace:
(?m)\bold_variable\b

With:
new_variable

Use \b for word boundaries.

Code Style Compliance

Standardize spacing around symbols:

if(test == 1){ 

}

Replace: 
(?m)\bif\b\((.*)\)(\s*){

With:
if (\\1) {

This neatly fixes spacing issues.

Regex replacements enables large-scale refactors.

Multiline Replace Tips and Tricks

Some handy tips for multilined search-and-replace:

• Start with simple wildcard finds and build up to full regex.
• Scope replaces narrowly at first and broaden once validated.
• Mind indentation – use \t, \r\n, or \n newlines as needed.
• Review files after multiline updates and revert problematic changes.
• Consider enabling regex . matches newline mode for convenience.
• Use named capture groups for readability with complex replacements.
• Break long find-and-replace expressions into separate steps when possible.

Following these tips will result in smoother multiline edits.

Advanced Multiline Selection Tricks

Some useful advanced selection techniques:

Column Selection

Hold Alt and select to column highlight:

Finds, moves, and edits entire columns.

Find All Occurances

Use Ctrl + Shift + L to select all matches:

Jumps between occurences.

Adjacent Lines

Hold Ctrl+Click to add contiguous lines.

Rectangular Blocks

Hold Alt + Shift while clicking and dragging for a rectangular selection.

These tricks expand multilined manipulation capabilities.

Multiline Editing in Other Visual Studio Languages

Beyond C#, robust multiline find-and-replace works in:

JavaScript

Update CSS class names across .js files:

$('.old-class')

Replace: 
(\$)\(\s*['"].*['"]\s*\) 

With:  
$1('.new-class')

Python

Standardize string quotes usage:

'old string'

Replace: 
(?m)(["'])(.*)(["']) 

With:
"\\2"

XML

Rename elements throughout config files:

<oldTag>
</oldTag>

Replace:
(?m)<oldTag>.*</oldTag>

With:  
<newTag>
</newTag> 

Markdown

Correct image links:

![alt](oldlink)

Replace:  
!\[.*]\((.*)\)

With:
![\\1](newlink)

Regex replacements work across major VS languages.

Multiline Selection and Editing Keyboard Shortcuts

Useful Visual Studio keyboard shortcuts:

• Ctrl + Click: Add cursor for multiline editing
• Alt + Shift + Arrow: Column selection
• Ctrl + Alt + Up/Down: Add line above or below
• Ctrl + Enter: Insert line below cursor
• Ctrl + Shift + L: Select all occurrences
• Ctrl + F: Open multiline find/replace dialog

Keyboard shortcuts accelerate multilined workflows.

Multiline Find and Replace Risks

Some risks to watch out for:

• Unintended matches from overbroad regex or scope.
• Forgetting to escape special regex characters.
• Spanning too much code at once leading to widespread unintended changes.
• Changing text within comments and strings.
• Impacting overlapping match regions with multiple successive replaces.
• Forgetting to review replacements before committing them.

Going slowly and carefully at first is advisable.

Alternative Multiline Editing Options

Some alternatives to Visual Studio find-and-replace:

Sublime Text Multicursor

Enables direct multiline editing:

However, less scope control than true find-and-replace.

grep and sed

Powerful command line search-and-replace:

grep -r "find" /code | sed -e "s/find/replace/"

But easy to make mistakes without previews.

Code Search Tools

Services like Sourcegraph and Silver Searcher enable code searching without also handling replacements.

Visual Studio’s balance of safety and power has advantages.

Sample Multiline Find and Replace Workflow

Walkthrough of a full safe multilined refactor workflow:

1. Make a narrow initial selection to preview the intended change.
2. Craft a focused regex that matches only the desired lines.
3. Test run the replace within the selection and validate the results.
4. Broaden the scope slightly and re-test, iterating until confident.
5. Do one final verification in a clone of the code before running globally.
6. Scope to entire project/solution and execute while carefully reviewing changes.
7. Spot check files to verify accuracy.
8. Consider running source control diffs to review impact.
9. Revert any improperly matched file edits as needed.

This careful, iterative approach ensures safety.

Key Benefits of Multiline Editing in Visual Studio

Mastering Visual Studio’s multilined find-and-replace:

• Helps complete large scale refactors easily.
• Avoids hours of risky manual search-and-replace.
• Enables superior codebase-wide find-and-replace scope.
• Makes codebase edits accurate with strong regex and previewing.
• Improves consistency with project-wide formatting standardization.
• Integrates robustly across languages and file types.
• Reduces introduction of regressions relative to global manual edits.

Smooth multilined workflows accelerate development and maintain cleaner code.

Conclusion

Visual Studio delivers industry-leading support for versatile multiline text manipulation through its robust find-and-replace functionality. Developers can accomplish codebase-wide changes ranging from style standardization to large scale refactors with speed and accuracy.

By leveraging features like regex, scoping, and previews, developers can avoid common find-and-replace pitfalls. Following a careful iterative approach ensures global changes can be made fearlessly. Deep multiline editing mastery pays dividends across virtually any Visual Studio project.