C# Xamarin Android -在onCreate()之外更改按钮属性

using Android.App;
using Android.OS;
using Android.Widget;

namespace XamarinAndroidApp
{
    [Activity(Label = "XamarinAndroidApp", MainLauncher = true)]
    public class MainActivity : Activity
    {
        private Button myButton;

        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);
            SetContentView(Resource.Layout.activity_main);

            myButton = FindViewById<Button>(Resource.Id.myButton);
            myButton.Click += MyButton_Click;
        }

        protected override void OnResume()
        {
            base.OnResume();
            // 在onResume()方法中更改按钮属性
            myButton.Enabled = false;
            myButton.Text = "按钮已禁用";
        }

        private void MyButton_Click(object sender, System.EventArgs e)
        {
            // 在onClick()方法中更改按钮属性
            myButton.Enabled = true;
            myButton.Text = "按钮已启用";
        }
    }
}