Download, edit, and upload Excel file in OneDrive using Microsoft Graph and XlsIO

private System.ComponentModel.IContainer components = null;

private void InitializeComponent()
{
    this.components = new System.ComponentModel.Container();
    this.button1 = new System.Windows.Forms.Button();
    this.graphLoginComponent1 = new Microsoft.Toolkit.Services.WinForms.GraphLoginComponent(this.components);
    this.SuspendLayout();
    // 
    // button1
    // 
    this.button1.Location = new System.Drawing.Point(325, 152);
    this.button1.Name = "button1";
    this.button1.Size = new System.Drawing.Size(95, 48);
    this.button1.TabIndex = 0;
    this.button1.Text = "Edit Excel";
    this.button1.UseVisualStyleBackColor = true;
    this.button1.Click += new System.EventHandler(this.button1_Click);
    // 
    // graphLoginComponent1
    // 
    this.graphLoginComponent1.ClientId = null;
    this.graphLoginComponent1.Scopes = null;
    // 
    // Form1
    // 
    this.AutoScaleDimensions = new System.Drawing.SizeF(9F, 20F);
    this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
    this.ClientSize = new System.Drawing.Size(800, 450);
    this.Controls.Add(this.button1);
    this.Name = "Form1";
    this.Text = "Form1";
    this.ResumeLayout(false);
 
}

private System.Windows.Forms.Button button1;
private Microsoft.Toolkit.Services.WinForms.GraphLoginComponent graphLoginComponent1;

using Microsoft.Identity.Client;
using Syncfusion.XlsIO;

private async void button1_Click(object sender, EventArgs e)
{
    PublicClientApplication clientApp = new PublicClientApplication(ConfigurationManager.AppSettings["clientId"].ToString());
    Microsoft.Graph.GraphServiceClient graphClient = new Microsoft.Graph.GraphServiceClient("https://graph.microsoft.com/v1.0", new Microsoft.Graph.DelegateAuthenticationProvider(async (requestMessage) => {
        requestMessage.Headers.Authorization = new AuthenticationHeaderValue("bearer", await GetTokenAsync(clientApp));
    }));
    try
    {
        //Initialize ExcelEngine
        ExcelEngine excelEngine = new ExcelEngine();
 
        //Initialize IApplication
        IApplication application = excelEngine.Excel;
 
        //Enable fast record parsing
        application.UseFastRecordParsing = true;
 
        //Get the file from OneDrive into stream
        var stream = await graphClient.Me.Drive.Root.ItemWithPath("Sample.xlsx").Content.Request().GetAsync();
 
        //Set the stream position as '0'
        stream.Position = 0;
 
        //Initialize new MemoryStream and copy the existing stream to this new MemeoryStream
        MemoryStream file = new MemoryStream();
        stream.CopyTo(file);
 
        //Set the stream position as '0'
        file.Position = 0;
 
        //Load the stream into IWorkbook
        IWorkbook workbook = application.Workbooks.Open(file);
 
        //Modify the Excel document
        workbook.Worksheets[0].Range["A2"].Text = "Syncfusion Essential XlsIO";
 
        //Save the modified Excel document as new MemoryStream
        MemoryStream outputStream = new MemoryStream();
        workbook.SaveAs(outputStream);
 
        //Set the stream position as '0'
        outputStream.Position = 0;
 
        //Upload the modified Excel document to OneDrive again
        await graphClient.Me.Drive.Root.ItemWithPath("ModifiedFile2.xlsx").Content.Request().PutAsync<Microsoft.Graph.DriveItem>(outputStream);
 
        //Close the workbook
        workbook.Close();
 
        //Dispose the ExcelEngine
        excelEngine.Dispose();
    }
 
    catch (Microsoft.Graph.ServiceException ex)
    {
        Console.WriteLine(ex);
    }
}

async Task<string> GetTokenAsync(PublicClientApplication clientApp)
{
    //need to pass scope of activity to get token  
    string[] Scopes = { "User.Read Files.ReadWrite Files.ReadWrite.All" };
    string token = null;
    AuthenticationResult authResult = await clientApp.AcquireTokenAsync(Scopes);
    token = authResult.AccessToken;
    return token;
}