Loading and saving workbook in .NET MAUI

24 Jul 202621 minutes to read

Prerequisites

  • Visual Studio 2022 (17.3 or later) on Windows with the Mobile development with .NET workload (which includes the .NET MAUI workload) installed.
  • Create a .NET MAUI App project.
  • Install the Syncfusion.XlsIO.NET NuGet package in your project.
  • Register your Syncfusion® license key in your project. Refer to the licensing overview for details.

NOTE

Before proceeding, add Sample.xlsx to the project and set its Build Action to Embedded Resource in the file properties so it can be loaded with GetManifestResourceStream.

NOTE

Starting with v16.2.0.x, if you reference Syncfusion® assemblies from trial setup or from the NuGet feed, you also have to add the Syncfusion.Licensing assembly reference and include a license key in your projects. Please refer to this link to know about registering the Syncfusion® license key in your applications to use our components.

Opening an existing workbook from stream

You can open an existing workbook from stream by using the overloads of Open methods of IWorkbooks interface.

// Create a new instance of ExcelEngine
using (ExcelEngine excelEngine = new ExcelEngine())
{
    // Initialize IApplication
    IApplication application = excelEngine.Excel;

    // Load the embedded resource into a stream
    Assembly executingAssembly = typeof(App).GetTypeInfo().Assembly;
    using (Stream inputStream = executingAssembly.GetManifestResourceStream("MAUISample.Sample.xlsx"))
    {
        // Open the workbook through the Open method of IWorkbooks
        IWorkbook workbook = application.Workbooks.Open(inputStream);
    }
}

Saving an Excel workbook to stream

You can also save the created or manipulated workbook to stream using overloads of SaveAs methods.

// Create a new instance of ExcelEngine
using (ExcelEngine excelEngine = new ExcelEngine())
{
    // Initialize IApplication
    IApplication application = excelEngine.Excel;

    // Load the embedded resource into a stream
    Assembly executingAssembly = typeof(App).GetTypeInfo().Assembly;
    using (Stream inputStream = executingAssembly.GetManifestResourceStream("MAUISample.Sample.xlsx"))
    {
        // Open the workbook
        IWorkbook workbook = application.Workbooks.Open(inputStream);

        // To-Do: some manipulation

        // Set the version of the workbook
        workbook.Version = ExcelVersion.Xlsx;

        // Save the workbook to a memory stream
        using (MemoryStream outputStream = new MemoryStream())
        {
            workbook.SaveAs(outputStream);
            outputStream.Position = 0;

            // Hand the memory stream to the platform-specific SaveService
            SaveService saveService = new SaveService();
            saveService.SaveAndView("Output.xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", outputStream);
        }
    }
}

Save Service class in portable project

Add the new class file with name as SaveService to the Project and add below code in it. This is the helper class used to save and view the Excel file in windows, android, iOS and MAC devices.

namespace MAUISample.Services
{
  public partial class SaveService
  {
    //Method to save document as a file and view the saved document.
    public partial void SaveAndView(string filename, string contentType, MemoryStream stream);
  }
}

Save and View the Excel document in windows

Add the new class file with name SaveWindows file under Project-> Platforms-> Windows directory to save and view the Excel document in the windows machine and use the below code in it.

using Windows.Storage;
using Windows.Storage.Pickers;
using Windows.Storage.Streams;
using Windows.UI.Popups;

namespace MAUISample.Services
{
  public partial class SaveService
  {
    public async partial void SaveAndView(string filename, string contentType, MemoryStream stream)
    {
      StorageFile stFile;
      string extension = Path.GetExtension(filename);
      //Gets process windows handle to open the dialog in application process. 
      IntPtr windowHandle = System.Diagnostics.Process.GetCurrentProcess().MainWindowHandle;
      if (!Windows.Foundation.Metadata.ApiInformation.IsTypePresent("Windows.Phone.UI.Input.HardwareButtons"))
      {
        //Creates file save picker to save a file. 
        FileSavePicker savePicker = new();
        savePicker.DefaultFileExtension = ".xlsx";
        savePicker.SuggestedFileName = filename;
        //Saves the file as xlsx file.
        savePicker.FileTypeChoices.Add("XLSX", new List<string>() { ".xlsx" });
        WinRT.Interop.InitializeWithWindow.Initialize(savePicker, windowHandle);
        stFile = await savePicker.PickSaveFileAsync();
      }
      else
      {
        StorageFolder local = ApplicationData.Current.LocalFolder;
        stFile = await local.CreateFileAsync(filename, CreationCollisionOption.ReplaceExisting);
      }
      if (stFile != null)
      {
        using (IRandomAccessStream zipStream = await stFile.OpenAsync(FileAccessMode.ReadWrite))
        {
          //Writes compressed data from memory to file.
          using Stream outstream = zipStream.AsStreamForWrite();
          outstream.SetLength(0);
          //Saves the stream as file.
          byte[] buffer = stream.ToArray();
          outstream.Write(buffer, 0, buffer.Length);
          outstream.Flush();
        }
        //Create message dialog box. 
        MessageDialog msgDialog = new("Do you want to view the document?", "File has been created successfully");
        UICommand yesCmd = new("Yes");
        msgDialog.Commands.Add(yesCmd);
        UICommand noCmd = new("No");
        msgDialog.Commands.Add(noCmd);

        WinRT.Interop.InitializeWithWindow.Initialize(msgDialog, windowHandle);

        //Showing a dialog box. 
        IUICommand cmd = await msgDialog.ShowAsync();
        if (cmd.Label == yesCmd.Label)
        {
          //Launch the saved file. 
          await Windows.System.Launcher.LaunchFileAsync(stFile);
        }
      }
    }
  }
}

Save and View the Excel document in Android

Add the new class file with name SaveAndroid file under Project-> Platforms-> Android directory to save and view the Excel document in the Android Device and use the below code in it.

using Android.Content;
using Android.OS;
using Java.IO;
using System;
using System.IO;
using System.Threading.Tasks;

namespace MAUISample.Services
{
  public partial class SaveService
  {
    public partial void SaveAndView(string filename, string contentType, MemoryStream stream)
    {
      string exception = string.Empty;
      string? root = null;

      if (Android.OS.Environment.IsExternalStorageEmulated)
      {
        root = Android.App.Application.Context!.GetExternalFilesDir(Android.OS.Environment.DirectoryDownloads)!.AbsolutePath;
      }
      else
        root = System.Environment.GetFolderPath(System.Environment.SpecialFolder.MyDocuments);

      Java.IO.File myDir = new(root + "/Syncfusion");
      myDir.Mkdir();
      Java.IO.File file = new(myDir, filename);

      if (file.Exists())
      {
        file.Delete();
      }

      try
      {
        FileOutputStream outs = new(file);
        outs.Write(stream.ToArray());

        outs.Flush();
        outs.Close();
      }
      catch (Exception e)
      {
        exception = e.ToString();
      }
      if (file.Exists())
      {
        if (Build.VERSION.SdkInt >= Android.OS.BuildVersionCodes.N)
        {
          var fileUri = AndroidX.Core.Content.FileProvider.GetUriForFile(Android.App.Application.Context, Android.App.Application.Context.PackageName + ".provider", file);
          var intent = new Intent(Intent.ActionView);
          intent.SetData(fileUri);
          intent.AddFlags(ActivityFlags.NewTask);
          intent.AddFlags(ActivityFlags.GrantReadUriPermission);
          Android.App.Application.Context.StartActivity(intent);
        }
        else
        {
          var fileUri = Android.Net.Uri.Parse(file.AbsolutePath);
          var intent = new Intent(Intent.ActionView);
          intent.SetDataAndType(fileUri, contentType);
          intent = Intent.CreateChooser(intent, "Open File");
          intent!.AddFlags(ActivityFlags.NewTask);
          Android.App.Application.Context.StartActivity(intent);
        }
      }
    }
  }
}

NOTE

Introduced a new runtime permission model for the Android SDK version 23 and above. So, include the following code for enabling the Android file provider to save and view the generated Excel document.

Create a new XML file with the name of provider_path.xml under the Resources-> xml folder of Android project and add the following code in it. Eg: Resources/xml/provider_path.xml

<?xml version="1.0" encoding="UTF-8" ?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
   <external-path name="external_files" path="."/>
</paths>

Add the following code to the AndroidManifest.xml file located under Properties folder.

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="1" android:versionName="1.0" package="com.companyname.MAUISample">
   <uses-sdk android:minSdkVersion="19" android:targetSdkVersion="27" />
   <application android:label="MAUISample.Android">
      <provider android:name="androidx.core.content.FileProvider"
         android:authorities="${applicationId}.provider"
         android:exported="false"
         android:grantUriPermissions="true">
         <meta-data android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/provider_paths" />
      </provider>
   </application>
</manifest>

Save and View the Excel document in iOS

Add the new class file with name SaveIOS file under Project-> Platforms-> iOS directory to save and view the Excel document in the iOS Device and use the below code in it.

using QuickLook;
using UIKit;

namespace MAUISample.Services
{
  public partial class SaveService
  {
    public partial void SaveAndView(string filename, string contentType, MemoryStream stream)
    {
      string exception = string.Empty;
      string path = Environment.GetFolderPath(Environment.SpecialFolder.Personal);
      string filePath = Path.Combine(path, filename);
      try
      {
        FileStream fileStream = File.Open(filePath, FileMode.Create);
        stream.Position = 0;
        stream.CopyTo(fileStream);
        fileStream.Flush();
        fileStream.Close();
      }
      catch (Exception e)
      {
        exception = e.ToString();
      }
      if (contentType != "application/html" || exception == string.Empty)
      {
#pragma warning disable CA1416 
        UIViewController? currentController = UIApplication.SharedApplication!.KeyWindow!.RootViewController;
#pragma warning restore CA1416 
        while (currentController!.PresentedViewController != null)
          currentController = currentController.PresentedViewController;

        QLPreviewController qlPreview = new();
        QLPreviewItem item = new QLPreviewItemBundle(filename, filePath);
        qlPreview.DataSource = new PreviewControllerDS(item);
        currentController.PresentViewController((UIViewController)qlPreview, true, null);
      }
    }
  }
}

Save and View the Excel document in MacCatalyst

Add the new class file with name SaveMAC file under Project-> Platforms-> MacCatalyst directory to save and view the Excel document in the MAC Device and use the below code in it.

using Foundation;
using QuickLook;
using UIKit;

namespace MAUISample.Services
{
  public partial class SaveService
  {
    public partial void SaveAndView(string filename, string contentType, MemoryStream stream)
    {
      string path = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
      string filePath = Path.Combine(path, filename);
      stream.Position = 0;
      //Saves the document
      using FileStream fileStream = new(filePath, FileMode.Create, FileAccess.ReadWrite);
      stream.CopyTo(fileStream);
      fileStream.Flush();
      fileStream.Dispose();
#pragma warning disable CA1416 
      //Launch the file
      UIViewController? currentController = UIApplication.SharedApplication!.KeyWindow!.RootViewController;
#pragma warning restore CA1416 
      while (currentController!.PresentedViewController != null)
        currentController = currentController.PresentedViewController;
      UIView? currentView = currentController.View;

      QLPreviewController qlPreview = new();
      QLPreviewItem item = new QLPreviewItemBundle(filename, filePath);
      qlPreview.DataSource = new PreviewControllerDS(item);
      currentController.PresentViewController((UIViewController)qlPreview, true, null);
    }
  }
}

public class QLPreviewItemFileSystem : QLPreviewItem
{
  readonly string _fileName, _filePath;

  public QLPreviewItemFileSystem(string fileName, string filePath)
  {
    _fileName = fileName;
    _filePath = filePath;
  }

  public override string PreviewItemTitle
  {
    get
    {
      return _fileName;
    }
  }
  public override NSUrl PreviewItemUrl
  {
    get
    {
      return NSUrl.FromFilename(_filePath);
    }
  }
}

public class QLPreviewItemBundle : QLPreviewItem
{
  readonly string _fileName, _filePath;
  public QLPreviewItemBundle(string fileName, string filePath)
  {
    _fileName = fileName;
    _filePath = filePath;
  }

  public override string PreviewItemTitle
  {
    get
    {
      return _fileName;
    }
  }
  public override NSUrl PreviewItemUrl
  {
    get
    {
      var documents = NSBundle.MainBundle.BundlePath;
      var lib = Path.Combine(documents, _filePath);
      var url = NSUrl.FromFilename(lib);
      return url;
    }
  }
}

public class PreviewControllerDS : QLPreviewControllerDataSource
{
  private readonly QLPreviewItem _item;

  public PreviewControllerDS(QLPreviewItem item)
  {
    _item = item;
  }

  public override nint PreviewItemCount(QLPreviewController controller)
  {
    return (nint)1;
  }

  public override IQLPreviewItem GetPreviewItem(QLPreviewController controller, nint index)
  {
    return _item;
  }
}

See Also