private async void AddBtn_Clicked(object sender, EventArgs e)
{
var item = new Todo(projectIdx);
var todoPage = new TodoItemPage();
todoPage.BindingContext = (Todo)item;
await Navigation.PushAsync(todoPage);
}
private async void ListView_ItemSelected(object sender, SelectedItemChangedEventArgs e)
{
var todoPage = new TodoItemPage();
todoPage.BindingContext = ((Todo)e.SelectedItem);
await Navigation.PushAsync(todoPage);
// listView.SelectedItem = null;
}