# As-You-Type Checking

> Underline misspelled words as users type in a Windows Forms TextControl: SpellChecker and IsSpellCheckingEnabled in the designer or code, and the context menu.

- **Product:** TX Spell .NET for Windows Forms
- **Section:** Documentation
- **Kind:** Topic
- **Path:** TX Spell .NET for Windows Forms > Spell Checking > As-You-Type Checking
- **Web URL:** https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/as-you-type/
- **LLMs URL:** https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/as-you-type/llms.txt
- **LLMs-Full URL:** https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/as-you-type/llms-full.txt

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## On This Page

- [How As-You-Type Checking Works](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/as-you-type/#how-as-you-type-checking-works)
- [Connect the Spell Checker in the Designer](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/as-you-type/#connect-the-spell-checker-in-the-designer)
- [Connect It in Code](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/as-you-type/#connect-it-in-code)
- [What the User Sees](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/as-you-type/#what-the-user-sees)
- [Control What Is Checked and Shown](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/as-you-type/#control-what-is-checked-and-shown)
- [Check a RichTextBox as the User Types](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/as-you-type/#check-a-richtextbox-as-the-user-types)
- [Check a TextBox When It Loses the Focus](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/as-you-type/#check-a-textbox-when-it-loses-the-focus)
- [Next Steps](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/as-you-type/#next-steps)

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## Nearby

- **Previous:** [Spell Checking](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/llms.txt)
- **Next:** [Checking on Demand](https://docs.textcontrol.com/tx-spell-dotnet-winforms/spell-checking/on-demand/llms.txt)