(MFC) Outlook -- Get Number of Emails

Gets the number of emails in an Outlook folder. This uses the OData $count system query option. See OData System Query Option $count for general information.

This example first gets the combined total number of messages across all folders.

Note: This example requires Chilkat v9.5.0.68 or greater.

Chilkat C/C++ Library Downloads

MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

#include <CkHttp.h>
#include <CkStringBuilder.h>
#include <CkJsonObject.h>
#include <CkHashtable.h>

void ChilkatSample(void)
    {
    CkString strOut;

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkHttp http;

    // Use your previously obtained access token here:
    // See the following examples for getting an access token:
    //    Get Microsoft Graph OAuth2 Access Token (Azure AD v2.0 Endpoint).
    //    Get Microsoft Graph OAuth2 Access Token (Azure AD Endpoint).
    //    Refresh Access Token (Azure AD v2.0 Endpoint).
    //    Refresh Access Token (Azure AD Endpoint).

    http.put_AuthToken("MICROSOFT_GRAPH_ACCESS_TOKEN");

    CkStringBuilder sbResponse;

    // This gets the combined total number of emails in all folders.
    bool success = http.QuickGetSb("https://graph.microsoft.com/v1.0/me/messages/$count",sbResponse);
    if ((success != true) && (http.get_LastStatus() == 0)) {
        strOut.append(http.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    CkJsonObject json;
    json.put_EmitCompact(false);

    // If the status code was not 200, then it failed and the response is likely JSON:
    if (http.get_LastStatus() != 200) {
        strOut.append("Status code = ");
        strOut.appendInt(http.get_LastStatus());
        strOut.append("\r\n");
        json.LoadSb(sbResponse);
        strOut.append(json.emit());
        strOut.append("\r\n");
        strOut.append("Failed.");
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // A success response payload contains just the integer value (it is not JSON)
    strOut.append("Combined Total Number of Emails = ");
    strOut.append(sbResponse.getAsString());
    strOut.append("\r\n");
    strOut.append("--");
    strOut.append("\r\n");

    // ---------------------------------------------------------------------------
    // To get the number of emails in a particular folder, we need to use the folder id.
    // 

    // In this example, we'd like to get number of messages in the folder "/Inbox/abc",
    // but we must specify the corresponding folder_id.  The best way to do this is to create
    // a local map of folderPaths-to-folderIds.
    // We'll use the map created by this example:  Create Outlook Folder Map)
    CkHashtable htFolderMap;
    CkStringBuilder sbMap;
    sbMap.LoadFile("qa_data/outlook/folderMap.xml","utf-8");
    htFolderMap.AddFromXmlSb(sbMap);

    // Get the ID for the "/Inbox/abc" folder:
    const char *folderId = htFolderMap.lookupStr("/Inbox/abc");
    if (htFolderMap.get_LastMethodSuccess() != true) {
        strOut.append("Folder ID not found");
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    http.SetUrlVar("folder_id",folderId);

    // Send the request get the folder information.
    // In this case we are NOT using the $count system query option.
    success = http.QuickGetSb("https://graph.microsoft.com/v1.0/me/mailFolders/{$folder_id}",sbResponse);
    if ((success != true) && (http.get_LastStatus() == 0)) {
        strOut.append(http.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    json.LoadSb(sbResponse);
    strOut.append(json.emit());
    strOut.append("\r\n");
    strOut.append("--");
    strOut.append("\r\n");

    if (http.get_LastStatus() != 200) {
        strOut.append("Status code = ");
        strOut.appendInt(http.get_LastStatus());
        strOut.append("\r\n");
        strOut.append("Failed.");
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // The successful JSON response looks like this;

    // 	{
    // 	  "@odata.context": "https://graph.microsoft.com/v1.0/$metadata#users('me')/mailFolders/$entity",
    // 	  "id": "AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAL8huv8AAAA=",
    // 	  "displayName": "abc",
    // 	  "parentFolderId": "AQMkADAwATM0MDAAMS1iNTcwLWI2NTEtMDACLTAwCgAuAAADsVyfxjDU406Ic4X7ill8xAEA5_vF7TKKdE6bGCRqXyl2PQAAAgEMAAAA",
    // 	  "childFolderCount": 2,
    // 	  "unreadItemCount": 0,
    // 	  "totalItemCount": 3
    // 	}
    // 

    // Get the integer value from the JSON like this:
    int totalItemCount = json.IntOf("totalItemCount");
    strOut.append("totalItemCount = ");
    strOut.appendInt(totalItemCount);
    strOut.append("\r\n");

    int childFolderCount = json.IntOf("childFolderCount");
    strOut.append("childFolderCount = ");
    strOut.appendInt(childFolderCount);
    strOut.append("\r\n");

    // etc..


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }