# SubTextPartCollection.Add Method

> Adds a new subtextpart to the document. Its position is defined through the SubTextPart.Start and SubTextPart.Length properties. If the subtextpart's length is zero, the current text selection is used to define the position.

- **Product:** TX Text Control .NET for Windows Forms
- **Section:** Reference
- **Kind:** Method
- **Introduced:** 23.0
- **Namespace:** `TXTextControl`
- **Package:** `TXTextControl.TextControl.WinForms.SDK` (assembly `TXTextControl.dll`, from the private NuGet feed or Text Control Offline Packages)
- **.NET Framework:** reference `TXTextControl.dll` from the setup
- **Path:** TX Text Control .NET for Windows Forms > Reference > TXTextControl > SubTextPartCollection.Add Method
- **Web URL:** https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol/subtextpartcollection/add-method/
- **LLMs URL:** https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol/subtextpartcollection/add-method/llms.txt
- **LLMs-Full URL:** https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol/subtextpartcollection/add-method/llms-full.txt

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## On This Page

- [Description](https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol/subtextpartcollection/add-method/#description)
- [Syntax](https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol/subtextpartcollection/add-method/#syntax)
- [Parameters](https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol/subtextpartcollection/add-method/#parameters)
- [Return Value](https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol/subtextpartcollection/add-method/#return-value)
- [Examples](https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol/subtextpartcollection/add-method/#examples)

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## Nearby

- **Previous:** [SubTextPartCollection Class](https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol/subtextpartcollection/llms.txt)
- **Next:** [SubTextPartCollection.AddResult Enumeration](https://docs.textcontrol.com/tx-text-control-dotnet-winforms/reference/txtextcontrol/subtextpartcollection/addresult-enumeration/llms.txt)