# Spell Checking > Add spell checking to Windows Forms apps with TXSpellChecker: underline words as users type, open the spelling dialog, read suggestions and ignore words. - **Product:** TX Spell .NET for Windows Forms - **Section:** Documentation - **Kind:** Topic - **Path:** TX Spell .NET for Windows Forms > Spell Checking - **955 words** - **Web URL:** https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/ - **LLMs URL:** https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/llms.txt - **LLMs-Full URL:** https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/llms-full.txt --- Spell checking in TX Spell .NET for Windows Forms reaches the user in two ways: misspelled words are underlined while they type, and a dialog walks through them when they ask for a check. Behind both is one `TXSpellChecker` component, which also hands your code the incorrect words and their suggestions. Read on for what users see and how you control it, from connecting the first editor to building a correction interface of your own. ![A TextControl with red zigzag lines under misspelled words and the spell check context menu of the word "sampke".](https://docs.textcontrol.com/assets/img/tx-spell-dotnet-winforms/textcontrol-context-menu.5b60b5a7.webp) ### How Spell Checking Works A [TXSpellChecker](https://docs.textcontrol.com/tx-spell-dotnet-winforms/reference/txtextcontrol-proofing/txspellchecker/llms-full.txt) on the form holds the dictionaries and does the checking. How it reaches the text depends on the control: - **TX Text Control** checks the words itself once its `SpellChecker` property names the spell checker. It underlines misspelled words, offers suggestions in its context menu and opens a spelling dialog, all without code. - **Any other control**, such as a `TextBox` or a `RichTextBox`, passes its text to the spell checker's `Check` method. The result is a list of incorrect words that your code marks, or that the spell check dialog of TX Spell .NET walks through. One spell checker serves every control on a form, and its dictionaries decide the languages. [Dictionaries and Languages](https://docs.textcontrol.com/tx-spell-dotnet-winforms/dictionaries/llms-full.txt) covers them. ### Find the Right Page | If you want to | Read | |---|---| | Underline misspelled words while the user types | [As-You-Type Checking](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/as-you-type/llms-full.txt) | | Start a check from a button and correct words in a dialog | [Checking on Demand](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/on-demand/llms-full.txt) | | Read the misspelled words and their suggestions in code | [Incorrect Words and Suggestions](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/suggestions/llms-full.txt) | | Skip words in capitals, with numbers, URLs or e-mail addresses | [Ignore Settings](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/ignore-settings/llms-full.txt) | | Use one spell checker for several editors | [Checking Multiple Controls](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/multiple-controls/llms-full.txt) | | Check only chosen headers, footers or text frames | [Checking Text Parts](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/text-parts/llms-full.txt) | | Build a correction panel or dialog of your own | [Spelling Correction Modes and UI Provider](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/correction-modes/llms-full.txt) | | React to corrections, dialogs and dictionary changes | [Events](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/events/llms-full.txt) | ### Where to Start 1. [As-You-Type Checking](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/as-you-type/llms-full.txt) connects the spell checker to an editor, the step every other page builds on. 2. [Checking on Demand](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/on-demand/llms-full.txt) adds the spelling dialog. 3. [Ignore Settings](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/ignore-settings/llms-full.txt) adjusts what is reported, before users meet false alarms. If the component is not on your form yet, [Getting Started](https://docs.textcontrol.com/tx-spell-dotnet-winforms/getting-started/llms-full.txt) sets it up. The dialogs and menus themselves, and how to change them, are the subject of [User Interface](https://docs.textcontrol.com/tx-spell-dotnet-winforms/user-interface/llms-full.txt). ### Pages in This Section - [As-You-Type Checking](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/as-you-type/llms-full.txt): red underlines in TX Text Control, and colored words in a `RichTextBox`. - [Checking on Demand](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/on-demand/llms-full.txt): the spelling dialogs of TX Text Control and TX Spell .NET, for any control. - [Incorrect Words and Suggestions](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/suggestions/llms-full.txt): `Check`, `CreateSuggestions` and the misspelled words of TX Text Control. - [Ignore Settings](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/ignore-settings/llms-full.txt): case, uppercase words, numbers, addresses, duplicates and ignore lists. - [Checking Multiple Controls](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/multiple-controls/llms-full.txt): one spell checker and one dialog for several editors. - [Checking Text Parts](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/text-parts/llms-full.txt): the main text, headers, footers and text frames in the dialog. - [Spelling Correction Modes and UI Provider](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/correction-modes/llms-full.txt): the correction modes and a data-bound correction panel. - [Events](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/events/llms-full.txt): every event of the spell checker, with its arguments. --- ## In This Section - [As-You-Type Checking](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/as-you-type/llms-full.txt): Underline misspelled words as users type in a Windows Forms TextControl: SpellChecker and IsSpellCheckingEnabled in the designer or code, and the context menu. - [Spelling Correction Modes and UI Provider](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/correction-modes/llms-full.txt): Build a data-bound Windows Forms correction panel with SpellingCorrectionUIProvider: correction modes, suggestions, dictionary choice, preview, manual edits. - [Events](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/events/llms-full.txt): Handle TXSpellChecker events in Windows Forms: IncorrectWordChanging, MisspelledWordChanging, dialog opening and closing, menu clicks and dictionary changes. - [Ignore Settings](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/ignore-settings/llms-full.txt): Choose which words TXSpellChecker skips in Windows Forms: IgnoreCase and IgnoreWord flags, Ignore and Ignore All, duplicates and a locked ignore list. - [Checking Multiple Controls](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/multiple-controls/llms-full.txt): Share one TXSpellChecker between several TextControls or RichTextBoxes in Windows Forms, and check all of them in one dialog with SpellCheckDialogClosing. - [Checking on Demand](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/on-demand/llms-full.txt): Open a spelling dialog from a button in Windows Forms: TextControl.SpellCheckDialog, SpellCheckDialog.Show for TX Text Control, and Check for a RichTextBox. - [Incorrect Words and Suggestions](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/suggestions/llms-full.txt): Find misspelled words with Check and IncorrectWords, create suggestions with CreateSuggestions, and replace MisspelledWords in a Windows Forms TextControl. - [Checking Text Parts](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/text-parts/llms-full.txt): Spell check headers, footers and text frames of a Windows Forms TextControl: TextParts, IgnoreInAllTextParts, and SetNext of SpellCheckDialogStateManager. --- ## Nearby - **Previous:** [Checking Text in Code](https://docs.textcontrol.com/tx-spell-dotnet-winforms/getting-started/in-code/llms-full.txt) - **Next:** [As-You-Type Checking](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/as-you-type/llms-full.txt)