# RichTextBox and TextBox

> Spell check the standard RichTextBox and TextBox of Windows Forms with TXSpellChecker: color misspelled words as users type and correct them in a dialog.

- **Product:** TX Spell .NET for Windows Forms
- **Section:** Documentation
- **Kind:** Topic
- **Path:** TX Spell .NET for Windows Forms > Getting Started > RichTextBox and TextBox
- **462 words**
- **Web URL:** https://docs.textcontrol.com/tx-spell-dotnet-winforms/getting-started/richtextbox/
- **LLMs URL:** https://docs.textcontrol.com/tx-spell-dotnet-winforms/getting-started/richtextbox/llms.txt
- **LLMs-Full URL:** https://docs.textcontrol.com/tx-spell-dotnet-winforms/getting-started/richtextbox/llms-full.txt

---

The standard text controls of Windows Forms have no spell checking of their own, but TX Spell .NET can check their text. Two short tutorials add it to a `RichTextBox`, and to a `TextBox` along the way: one marks misspelled words while the user types, the other opens the spell check dialog. Both need only the TX Spell .NET package, not TX Text Control.

![The Spelling dialog of TX Spell .NET over a RichTextBox, showing the misspelled word "sampke" with its suggestions.](https://docs.textcontrol.com/assets/img/tx-spell-dotnet-winforms/richtextbox-spelling-dialog.b515f6c9.webp)

### How It Works

With TX Text Control, the editor does most of the work. With a `RichTextBox` or a `TextBox`, your code does it:

- **You pass the text.** The [Check](https://docs.textcontrol.com/tx-spell-dotnet-winforms/reference/txtextcontrol-proofing/txspellchecker/check-method/llms-full.txt) method of the [TXSpellChecker](https://docs.textcontrol.com/tx-spell-dotnet-winforms/reference/txtextcontrol-proofing/txspellchecker/llms-full.txt) checks a string and lists the incorrect words with their positions in [IncorrectWords](https://docs.textcontrol.com/tx-spell-dotnet-winforms/reference/txtextcontrol-proofing/txspellchecker/incorrectwords-property/llms-full.txt).
- **You mark the words.** A `RichTextBox` can color them; a `TextBox` can report that its text contains mistakes.
- **You apply the corrections.** The spell check dialog tells your code which word the user changed, through the `IncorrectWordChanging` event, and your code changes the text.

### Recommended Order

1. [Check Spelling as You Type](https://docs.textcontrol.com/tx-spell-dotnet-winforms/getting-started/richtextbox/as-you-type/llms-full.txt): create the project, add the controls, and color misspelled words red while the user types. The page also checks a `TextBox` when it loses the focus.
2. [Open the Spell Check Dialog](https://docs.textcontrol.com/tx-spell-dotnet-winforms/getting-started/richtextbox/dialog/llms-full.txt): add a button that opens the dialog, and write each correction back into the `RichTextBox`.

### Pages in This Section

- [Check Spelling as You Type](https://docs.textcontrol.com/tx-spell-dotnet-winforms/getting-started/richtextbox/as-you-type/llms-full.txt): a `RichTextBox` that colors misspelled words, and a `TextBox` checked in its `Validating` event.
- [Open the Spell Check Dialog](https://docs.textcontrol.com/tx-spell-dotnet-winforms/getting-started/richtextbox/dialog/llms-full.txt): the spell check dialog of TX Spell .NET for a `RichTextBox`.

---

## In This Section

- [Check Spelling as You Type](https://docs.textcontrol.com/tx-spell-dotnet-winforms/getting-started/richtextbox/as-you-type/llms-full.txt): Color misspelled words red in a Windows Forms RichTextBox as users type with TXSpellChecker.Check and IncorrectWords, and check a TextBox in Validating.
- [Open the Spell Check Dialog](https://docs.textcontrol.com/tx-spell-dotnet-winforms/getting-started/richtextbox/dialog/llms-full.txt): Open the spell check dialog for a Windows Forms RichTextBox with Check and SpellCheckDialog.Show, and apply corrections in the IncorrectWordChanging event.

---

## Nearby

- **Previous:** [Open the Spell Check Dialog](https://docs.textcontrol.com/tx-spell-dotnet-winforms/getting-started/tx-text-control/dialog/llms-full.txt)
- **Next:** [Check Spelling as You Type](https://docs.textcontrol.com/tx-spell-dotnet-winforms/getting-started/richtextbox/as-you-type/llms-full.txt)