Read and save data from C# app onto SharePoint

Question

For security reasons, our business is required to maintain a visitor control log to track when external guests enter and leave the premises.

When our infrastructure used to have on-prem file/storage servers, I had written a simple app that enabled the guests to check in and out via a public kiosk. When checking in, visitors' names, their internal contacts, and check-in times recorded in an Excel spreadsheet on a shared drive; upon checking out, the system would find them in the spreadsheet and append their check-out time. This was achieved using the DocumentFormat.OpenXml SDK.

We have since transitioned entirely to the cloud with SharePoint Online replacing our file servers, and I was trying to find some way to achieve something similar to the above without any success.

The options I found were the following:

1. Map SharePoint Online site onto the local drive. Windows 10/11 KIOSK mode does not allow access to local drive.
2. Save file to local drive and upload it. Windows 10/11 KIOSK mode does not allow access to local drive.
3. Use Microsoft Graph A little stuck on how to find the ID of the file to be read from/written to.

Any pointers in the right direction, particularly with Microsoft Graph and identifying the file I intend to use, would be much appreciated.

Answer 1

Hi @Thomas Lu ,

Per my research and testing, you can use the follow graph api to find ID of the file in the list:

GET https://graph.microsoft.com/v1.0/sites/{site-id}/lists/{list-id}/items/{itemid}  

By the way, do you want to display the check-in/check-out information directly in a SharePoint list, or do you still store the information in excel and then upload the excel to SharePoint?

I did a test using CSOM, in my test, to determine if the user exists in the list, if not, add the user and the check-in time to that list, if it exists, then add the check-out time. Here is my test code. Hope it can help you :

       static void Main(string[] args)  
        {  
            var clientContext = GetonlineContext();  
            Web web = clientContext.Web;  
            List targetList = clientContext.Web.Lists.GetByTitle("ListTest");  
            CamlQuery oQuery = new CamlQuery();  
            oQuery.ViewXml = @"<View><Query><Where>  
                                <Eq>  
                                <FieldRef Name='name' />  
                                <Value Type='Text'>zella</Value>  
                                </Eq>  
                                </Where></Query></View>";  
  
            ListItemCollection oItems = targetList.GetItems(oQuery);  
            clientContext.Load(oItems);  
            clientContext.ExecuteQuery();  
            ListItem oItem = oItems.FirstOrDefault();  
            if(oItem !=null)  
            {  
                oItem["check_x002d_outtimes"] = DateTime.UtcNow;  
                oItem.Update();  
                clientContext.ExecuteQuery();  
            }  
            else  
            {  
                ListItemCreationInformation oListItemCreationInformation = new ListItemCreationInformation();  
                ListItem oItemadd = targetList.AddItem(oListItemCreationInformation);  
                oItemadd["name"] = "zella";  
                oItemadd["check_x002d_intimes"] = DateTime.UtcNow;  
                oItemadd.Update();  
                clientContext.ExecuteQuery();  
            }  
        }  

if not exists :
if exists:

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