Double rus;
 Double las=32;
 Entry name = new Entry
        {

            //Label = "Баллы:",
            Placeholder = "введите баллы",
            Keyboard = Keyboard.Numeric,

        };
    rus= Convert.ToDouble(name.Text);

private void Dobavit_Clicked(object sender, EventArgs e)
    {
        Button dobavit = (Button)sender;
        if (rus==las)
        { dobavit.Text = "сработало!";


        dobavit.BackgroundColor = Color.DarkBlue; }

    }