The C1XLBook.CalculationMode property specifies the calculation mode for all formulas in the workbook. The CalculationMode enumeration provides three options: Manual (you manually perform the calculation), Auto (the calculation is automatically performed), or AutoNoTable (the calculation is performed except on tables).

In XAML View

1. Right-click References in the Solution Explorer and select Add Reference from the list.
   1. Browse to find C1.UWP.Excel.dll.
   2. Click OK to add the assembly reference to your application.
2. In XAML View, place your cursor between the <Grid> </Grid> tags.
3. Add two standard Button controls and one standard TextBox control to the page.
   1. Edit the markup for the first button so that it resembles the following:

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      <Button x:Name="HelloButton" Content="Click Hello" />

   2. Edit the markup for the second button so that it resembles the following:

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      <Button x:Name="SaveButton" Content="Save" />

   3.  Edit the markup for the TextBox control so that it resembles the following:

      Markup	Copy Code
      <TextBox Name="_tbContent" Text="Empty" IsReadOnly="True" AcceptsReturn="True" FontFamily="Courier New" Background="White" Margin="465,10,242,722" />

4. Create  an event named HelloButton_Click for HelloButton and switch to the code view of MainPage.xaml. This will also add a HelloButton_Click event to the code.
5. Switch back to Design View and double-click the SaveButton to add a SaveButton_Click event to the code. This will open the Code View.

In Code View

To set the calculation mode, follow these steps:

1. Add a using statement to the top of the page:

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   using C1.Xaml.Excel;

2. Add the following code to the MainPage class so that it resembles the following:

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   public sealed partial class MainPage : Page { C1XLBook _book; }

3. Create a C1XLBook by adding the following code to the InitializeComponent() method:

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   _book = new C1XLBook();

4. Add the RefreshView() method. You will call this method later in the code:

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   void RefreshView() { }

5. Add a simple formula to perform a calculation.

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   private void HelloButton_Click(object sender, RoutedEventArgs e) { // step 1: create a new workbook _book = new C1XLBook(); // step 2: get the default sheet and give it a name XLSheet sheet = _book.Sheets[0]; // step 3: add a simple formula sheet[7, 0].Value = "Formula: 5!"; sheet[7, 1].Value = 122; sheet[7, 1].Formula = "1*2*3*4*5"; _book.CalculationMode = CalculationMode.Auto; // step 4: allow user to save the file _tbContent.Text = "'Hello World' workbook has been created, you can save it now."; RefreshView(); }[ES5]

6. Save the workbook.

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   async void SaveButton_Click(object sender, RoutedEventArgs e) { Debug.Assert(_book != null); var picker = new Windows.Storage.Pickers.FileSavePicker(); picker.SuggestedStartLocation = Windows.Storage.Pickers.PickerLocationId.DocumentsLibrary; picker.FileTypeChoices.Add("Open XML Excel file", new List<string>() { ".xlsx" }); picker.FileTypeChoices.Add("BIFF Excel file", new List<string>() { ".xls" }); picker.SuggestedFileName = "New Book"; var file = await picker.PickSaveFileAsync(); if (file != null) { try { // step 1: save file var fileFormat = Path.GetExtension(file.Path).Equals(".xls") ? FileFormat.Biff8 : FileFormat.OpenXml; await _book.SaveAsync(file, fileFormat); // step 2: user feedback _tbContent.Text = string.Format("File has been saved to: {0}.", file.Path); RefreshView(); } catch (Exception x) { _tbContent.Text = string.Format("EXCEPTION: {0}", x.Message); } } }

Run the project and save and open the Excel file. Notice that the value for the cell in (7,1) is 120, or the total of 1*2*3*4*5, not 122, since we set the CalculationMode to Auto.