C# VSTO Persist Data Between Sessions

I discovered that you can use the Application Settings feature to persist data between application execution sessions for VSTO addins/smart documents. For those not familiar with the Settings object see MSDN’s Using Settings in C#, this is a good place to start. I discovered that a settings file can co-exist with the assemblies installed.

Below is an example where a generic VSTO Excel document is created. A user setting is created and named ColdStorage. It is important in Visual Studio to have that as a user setting so the value can be propagated between user sessions; Otherwise it is an application setting value which is readonly and will fail for our purposes. So set that value.


  1. Create a VSTO Excel document in VS2005.
  2. Create a user setting named ColdStorage as type string.
  3. Copy the below code into the Workbook startup and shutdown method


private void ThisWorkbook_Startup(object sender, System.EventArgs e)

// Write current value from storage to a sheet

Excel.Range rangeB2 = Globals.Sheet1.get_Range("B2", missing);

rangeB2.Value2 = ExcelWorkbookTestSettings.Properties.Settings.Default.ColdStorage;



private void ThisWorkbook_Shutdown(object sender, System.EventArgs e)
    // Read from the sheet and save
    Excel.Range rangeB = Globals.Sheet1.get_Range("B2", missing);

    ExcelWorkbookTestSettings.Properties.Settings.Default.ColdStorage = rangeB.Value2.ToString();



One Comment

  1. Peter says:

    Thank you – very easy!

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