# Data Source Configuration Files

> Why Report Data Source Configuration files (.rdsc) work in Windows Forms only, and how WPF apps replace them with DataSets, relations and their own queries.

- **Product:** TX Text Control .NET for WPF
- **Section:** Documentation
- **Kind:** Topic
- **Path:** TX Text Control .NET for WPF > Mail Merge and Reporting > Data Sources > Data Source Configuration Files
- **Web URL:** https://docs.textcontrol.com/tx-text-control-dotnet-wpf/mail-merge/data-sources/configuration-files/
- **LLMs URL:** https://docs.textcontrol.com/tx-text-control-dotnet-wpf/mail-merge/data-sources/configuration-files/llms.txt
- **LLMs-Full URL:** https://docs.textcontrol.com/tx-text-control-dotnet-wpf/mail-merge/data-sources/configuration-files/llms-full.txt

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## On This Page

- [What a Configuration File Does](https://docs.textcontrol.com/tx-text-control-dotnet-wpf/mail-merge/data-sources/configuration-files/#what-a-configuration-file-does)
- [Why It Doesn't Work in WPF](https://docs.textcontrol.com/tx-text-control-dotnet-wpf/mail-merge/data-sources/configuration-files/#why-it-doesn-t-work-in-wpf)
- [What to Do Instead in WPF](https://docs.textcontrol.com/tx-text-control-dotnet-wpf/mail-merge/data-sources/configuration-files/#what-to-do-instead-in-wpf)
- [Next Steps](https://docs.textcontrol.com/tx-text-control-dotnet-wpf/mail-merge/data-sources/configuration-files/#next-steps)

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## Nearby

- **Previous:** [JSON and XML](https://docs.textcontrol.com/tx-text-control-dotnet-wpf/mail-merge/data-sources/json-xml/llms.txt)
- **Next:** [Merge Fields](https://docs.textcontrol.com/tx-text-control-dotnet-wpf/mail-merge/fields/llms.txt)