I find this below code using Blogger API v3..
this below code is working but the problem is, it is asking for blogger login to user. I used this code in Apps then how the user login into my blogger..
var credential = await GoogleWebAuthorizationBroker.AuthorizeAsync(
new Uri("ms-appx:///Json/client_secret.json"),
new[] { BloggerService.Scope.Blogger },
"lartpeopleindiancinema@gmail.com",
CancellationToken.None);
var initializer = new BaseClientService.Initializer()
{
HttpClientInitializer = credential,
ApplicationName = "Admin Site Old",
};
service = new BloggerService(initializer);