You can use this code: (original idea from http://coderissues.com/questions/27512300/how-to-append-login-hint-usergmail-com-to-googlewebauthorizationbroker)
dsAuthorizationBroker.RedirectUri = "my localhost redirect uri";
UserCredential credential = await dsAuthorizationBroker.AuthorizeAsync(...
dsAuthorizationBroker.cs
using System;
using System.Collections.Generic;
using System.Threading;
using System.Threading.Tasks;
using Google.Apis.Auth.OAuth2;
using Google.Apis.Auth.OAuth2.Flows;
using Google.Apis.Auth.OAuth2.Requests;
using Google.Apis.Util.Store;
namespace OAuth2
{
public class dsAuthorizationBroker : GoogleWebAuthorizationBroker
{
public static string RedirectUri;
public new static async Task<UserCredential> AuthorizeAsync(
ClientSecrets clientSecrets,
IEnumerable<string> scopes,
string user,
CancellationToken taskCancellationToken,
IDataStore dataStore = null)
{
var initializer = new GoogleAuthorizationCodeFlow.Initializer
{
ClientSecrets = clientSecrets,
};
return await AuthorizeAsyncCore(initializer, scopes, user,
taskCancellationToken, dataStore).ConfigureAwait(false);
}
private static async Task<UserCredential> AuthorizeAsyncCore(
GoogleAuthorizationCodeFlow.Initializer initializer,
IEnumerable<string> scopes,
string user,
CancellationToken taskCancellationToken,
IDataStore dataStore)
{
initializer.Scopes = scopes;
initializer.DataStore = dataStore ?? new FileDataStore(Folder);
var flow = new dsAuthorizationCodeFlow(initializer);
return await new AuthorizationCodeInstalledApp(flow,
new LocalServerCodeReceiver())
.AuthorizeAsync(user, taskCancellationToken).ConfigureAwait(false);
}
}
public class dsAuthorizationCodeFlow : GoogleAuthorizationCodeFlow
{
public dsAuthorizationCodeFlow(Initializer initializer)
: base(initializer) { }
public override AuthorizationCodeRequestUrl
CreateAuthorizationCodeRequest(string redirectUri)
{
return base.CreateAuthorizationCodeRequest(dsAuthorizationBroker.RedirectUri);
}
}
}