Delphi 11 TEdgeBrowser webview2 slow load

Question

I am working on porting an app from TWebBrowser to TEdgeBrowser. I am utilizing the latest WebView2Loader from the Nuget site and have seen the same consistent problem with all versions of WebView2Loader across every version going back to January 2021.

The TEdgeBrowser works well, but the first load of any page can take anywhere from 14 seconds to as much as 24 seconds, usually between 14-18 seconds. Once the first page is loaded, any subsequent page loads execute as quickly as you would expect them to in a full browser.

I specify a UserDataFolder and a BrowserExecutableFolder, as well as OnCreateWebViewCompleted,OnNavigationStarting, and OnNavigationCompleted events.

I check for any of the error constants defined in the interface code but the only error that comes back is 'COREWEBVIEW2_WEB_ERROR_STATUS_UNKNOWN', which occurs every time I successfully navigate to a web page.

Does anyone have any insight into what could be causing this delay? I can run my embedded browser next to Microsft Edge and Edge loads quickly as expected, but the TEdgeBrowser always has the initial delay.

Any assistance would be greatly appreciated.

unit main;

interface

uses
  Winapi.Windows,
  Winapi.Messages,
  System.SysUtils,
  System.Variants,
  System.Classes,
  Vcl.Graphics,
  Vcl.Controls,
  Vcl.Forms,
  Vcl.Dialogs,
  Winapi.WebView2,
  Winapi.ActiveX,
  Vcl.Edge,
  Vcl.StdCtrls,
  Vcl.ExtCtrls,
  Vcl.OleCtrls,
  Vcl.ComCtrls,
  Vcl.Mask;

type
  TForm2 = class(TForm)
    Panel1: TPanel;
    Button1: TButton;
    Edit1: TEdit;
    moLog: TMemo;
    Splitter1: TSplitter;
    edNavElapsedTime: TLabeledEdit;
    PageControl1: TPageControl;
    tsEB: TTabSheet;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    FStart: TDateTime;
    FStop: TDateTime;
    FEB: TEdgeBrowser;
    procedure CreateWebViewCompleted(Sender: TCustomEdgeBrowser; AResult: HResult);
    procedure NavigationCompleted(Sender: TCustomEdgeBrowser; IsSuccess: Boolean; WebErrorStatus: COREWEBVIEW2_WEB_ERROR_STATUS);
    procedure NavigationStarting(Sender: TCustomEdgeBrowser; Args: TNavigationStartingEventArgs);
  end;

var
  Form2: TForm2;

implementation

{$R *.dfm}

uses
  System.DateUtils;

procedure LogEntry(ALogEntry: UnicodeString);
begin
  Form2.moLog.Lines.Insert(0,'[' + DateTimeToStr(Now) + ']: ' + ALogEntry);
end;

procedure TForm2.FormCreate(Sender: TObject);
var
  sUserCacheFolder,sExeFolder: UnicodeString;
begin
  sExeFolder := ExtractFileDir(Application.ExeName);
  sUserCacheFolder := sExeFolder + '\edgecache';
  if not ForceDirectories(sUserCacheFolder) then
    raise Exception.Create('Error: Failed to create Edge Browser user cache folder. Check directory file access rights.');

  FEB := TEdgeBrowser.Create(tsEB);
  FEB.Parent := tsEB;
  FEB.Align := alClient;
  if not FEB.WebViewCreated then
    FEB.CreateWebView;
  FEB.OnCreateWebViewCompleted := CreateWebViewCompleted;
  FEB.OnNavigationStarting := NavigationStarting;
  FEB.OnNavigationCompleted := NavigationCompleted;
  FEB.UserDataFolder := sUserCacheFolder;
  FEB.BrowserExecutableFolder := sExeFolder;
end;

procedure TForm2.NavigationCompleted(Sender: TCustomEdgeBrowser;     IsSuccess: Boolean; WebErrorStatus: COREWEBVIEW2_WEB_ERROR_STATUS);
var
  sErr: UnicodeString;
  yr,mon,day,hr,min,sec,msec: Word;
begin
  if IsSuccess then
    LogEntry('Navigation completed successfully');
  sErr := '';
  case WebErrorStatus of
//    COREWEBVIEW2_WEB_ERROR_STATUS_UNKNOWN: sErr := 'UNKNOWN'; // seems to be useless
    COREWEBVIEW2_WEB_ERROR_STATUS_CERTIFICATE_COMMON_NAME_IS_INCORRECT: sErr := 'CERTIFICATE_COMMON_NAME_IS_INCORRECT';
    COREWEBVIEW2_WEB_ERROR_STATUS_CERTIFICATE_EXPIRED: sErr := 'CERTIFICATE_EXPIRED';
    COREWEBVIEW2_WEB_ERROR_STATUS_CLIENT_CERTIFICATE_CONTAINS_ERRORS: sErr := 'CLIENT_CERTIFICATE_CONTAINS_ERRORS';
    COREWEBVIEW2_WEB_ERROR_STATUS_CERTIFICATE_REVOKED: sErr := 'CERTIFICATE_REVOKED';
    COREWEBVIEW2_WEB_ERROR_STATUS_CERTIFICATE_IS_INVALID: sErr := 'CERTIFICATE_IS_INVALID';
    COREWEBVIEW2_WEB_ERROR_STATUS_SERVER_UNREACHABLE: sErr := 'SERVER_UNREACHABLE';
    COREWEBVIEW2_WEB_ERROR_STATUS_TIMEOUT: sErr := 'TIMEOUT';
    COREWEBVIEW2_WEB_ERROR_STATUS_ERROR_HTTP_INVALID_SERVER_RESPONSE:         sErr := 'ERROR_HTTP_INVALID_SERVER_RESPONSE';
    COREWEBVIEW2_WEB_ERROR_STATUS_CONNECTION_ABORTED: sErr := 'CONNECTION_ABORTED';
    COREWEBVIEW2_WEB_ERROR_STATUS_CONNECTION_RESET: sErr := 'CONNECTION_RESET';
    COREWEBVIEW2_WEB_ERROR_STATUS_DISCONNECTED: sErr := 'DISCONNECTED';
    COREWEBVIEW2_WEB_ERROR_STATUS_CANNOT_CONNECT: sErr := 'CANNOT_CONNECT';
    COREWEBVIEW2_WEB_ERROR_STATUS_HOST_NAME_NOT_RESOLVED: sErr := 'HOST_NAME_NOT_RESOLVED';
    COREWEBVIEW2_WEB_ERROR_STATUS_OPERATION_CANCELED: sErr := 'OPERATION_CANCELED';
    COREWEBVIEW2_WEB_ERROR_STATUS_REDIRECT_FAILED: sErr := 'REDIRECT_FAILED';
    COREWEBVIEW2_WEB_ERROR_STATUS_UNEXPECTED_ERROR: sErr := 'UNEXPECTED_ERROR';
  end;
  if Length(sErr) > 0 then
    LogEntry('Navigation completed error: ' + sErr);
  FStop := Now;
  DecodeDateTime(FStop - FStart,yr,mon,day,hr,min,sec,msec);
  edNavElapsedTime.Text := IntToStr(sec);
end;

procedure TForm2.NavigationStarting(Sender: TCustomEdgeBrowser; Args: TNavigationStartingEventArgs);
var
  pwc: PWideChar;
begin
  FStart := Now;
  Args.ArgsInterface.Get_uri(pwc);
  LogEntry('Navigation Starting to ' + pwc);
end;

procedure TForm2.Button1Click(Sender: TObject);
begin
  FEB.Navigate(edit1.text);
end;

procedure TForm2.CreateWebViewCompleted(Sender: TCustomEdgeBrowser; AResult: HResult);
begin
  if AResult = 0 then
    LogEntry('Create Web View Completed Successfully')
  else
    LogEntry('Error: Failed to create Web View ' + IntToStr(AResult));
end;

end.

You can find the latest webview2 runtime here: NuGet Gallery | Microsoft.Web.Webview2 1.0.1072.54

Also you will need to ensure that Microsoft Edge is installed, preferably the latest version.