In-Depth
Q&A: Use Word's Spell Checker in .NET
Use Word's spell check from within your .NET application.
Q:
I have a VB.NET Windows Forms application for which I'd like to add a spell checker when the user adds some text into the Comments textbox. I'd like to raise the spell checker when the control loses the focus and bring up a dialog box that prompts the user with some suggestions for unrecognized words.
A:
If you know that the user has Microsoft Word installed—hardly a rare occurrence—you can use the spell check engine provided by Word. In this case, you can prompt a dialog box that provides the functionalities you're looking for. Moreover, Word uses a reach dictionary when the spell checking mechanism is called.
Begin by adding a reference to the Microsoft Word template library. Fire up Visual Studio .NET, then select Project | Add Reference? and click on the COM tab of the Add Reference dialog box. Next, add the appropriate code into the TextBox control's Leave event (see Listing 1).
You need to launch the Microsoft Word application and create a new document when you copy the text from the TextBox control. Copy this text onto the clipboard using the SetDataObject shared method of the Clipboard class. Next, use the Paste method provided by the Word library's Content object to paste the text into the Word document. Calling the CheckSpelling method brings up the Spelling Checker dialog box. This dialog suggests possible corrections to implement, assuming it finds any words it doesn't recognize (see Figure 1). Finally, copy the document text onto the clipboard again and paste it into the TextBox control.