C# Xamarin Android中的EditText有多清晰

单击按钮后，我想在打开焦点时清除编辑文本字段

此代码是一个sms应用程序，我想在单击“发送”按钮再次键入另一条消息后，在聚焦该EditTExt字段时清除该EditTExt字段

我试图在axml文件中放置一个gotfocus属性，但它不起作用。。 我尝试在google上搜索，但找不到任何解决方案，其他程序员使用了gotfocus属性，但我认为gotfocus属性仅在xaml文件中可用，而在axml中不可用

using Android.App;
using Android.OS;
using Android.Support.V7.App;
using Android.Runtime;
using Android.Widget;
using Android.Content.PM;
using Android.Telephony;
using System;
using Android;
using Android.Content;
using Android.Support.V4.Content;
using Android.Support.V4.App;
using Android.Util;
using Android.Support.Design.Widget;
using Android.Views;
using Android.Text;
using System.Threading;

namespace MhylesOrderingApp
{
    [Activity(Label = "@string/app_name", Theme = "@style/AppTheme", MainLauncher = true)]
    public class MainActivity : AppCompatActivity, ActivityCompat.IOnRequestPermissionsResultCallback
    {
        static readonly int REQUEST_SENDSMS = 0;
        private SmsManager _smsManager;
        private BroadcastReceiver _smsSentBroadcastReceiver, _smsDeliveredBroadcastReceiver;
        View layout;
        //private ProgressBar spinner;
        static Android.App.ProgressDialog progress;
        //Android.App.ProgressDialog.progress;
        //public virtual ViewStates Visibility { get; set; }
        //SMSSentReceiver receiver;
        //private SmsManager smsManager;
        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);
            // Set our view from the "main" layout resource
            SetContentView(Resource.Layout.activity_main);

            layout = FindViewById(Resource.Id.sample_main_layout);



            //spinner = (ProgressBar)FindViewById(Resource.Id.progressBar1);
            var smsBtn = FindViewById<Button>(Resource.Id.btnSend);
            var phoneNum = FindViewById<EditText>(Resource.Id.phoneNum);
            var smsDate = "";
            var smsCustomer = FindViewById<EditText>(Resource.Id.txtCustomer);
            var smsAddress = FindViewById<EditText>(Resource.Id.txtAddress);
            var smsCustNo = FindViewById<EditText>(Resource.Id.txtCustomerNo);
            var smsOrderProd = FindViewById<EditText>(Resource.Id.txtOrderedProduct);
            var smsProdQty = FindViewById<EditText>(Resource.Id.txtProductQty);
            var smsUnit = FindViewById<EditText>(Resource.Id.txtUnit);
            var smsAgentName = FindViewById<EditText>(Resource.Id.txtAgentName);
            var scrollView = FindViewById<ScrollView>(Resource.Id.scrollViewing);


            DateTime now = DateTime.Now.ToLocalTime();
            smsDate = now.ToString();
            scrollView.SetBackgroundResource(Resource.Drawable.TextViewStyle);
            phoneNum.SetBackgroundResource(Resource.Drawable.EditTextStyle);
            smsCustomer.SetBackgroundResource(Resource.Drawable.EditTextStyle);
            smsAddress.SetBackgroundResource(Resource.Drawable.EditTextStyle);
            smsCustNo.SetBackgroundResource(Resource.Drawable.EditTextStyle);
            smsOrderProd.SetBackgroundResource(Resource.Drawable.EditTextStyle);
            smsProdQty.SetBackgroundResource(Resource.Drawable.EditTextStyle);
            smsUnit.SetBackgroundResource(Resource.Drawable.EditTextStyle);
            smsAgentName.SetBackgroundResource(Resource.Drawable.EditTextStyle);

            //spinner.Visibility = (ViewStates.Gone);
            progress = new Android.App.ProgressDialog(this);
            progress.Indeterminate = true;
            progress.SetProgressStyle(Android.App.ProgressDialogStyle.Spinner);
            progress.SetMessage("Sending.. Please wait!");
            progress.SetCancelable(false);
            _smsManager = SmsManager.Default;

            //receiver = new SMSSentReceiver();
            //smsManager = SmsManager.Default;
            //IntentFilter intentFilter = new IntentFilter("SMS_SENT");
            //intentFilter.AddAction("android.permission.SEND_SMS");

            ////RegisterReceiver(receiver, intentFilter);
            //smsBtn.Click += (s, e) =>
            //{
            //    var phone = phoneNum.Text;
            //    var message = sms.Text;

            //    var piSent = PendingIntent.GetBroadcast(this, 0, new Android.Content.Intent("SMS_SENT"), 0);
            //    //var piDelivered = PendingIntent.GetBroadcast(this, 0, new Android.Content.Intent("SMS_DELIVERED"), 0);

            //    smsManager.SendTextMessage(phone, null, message, piSent, null);
            //};

            smsBtn.Click += (s, e) =>
            {
                progress.Show();
                if (TextUtils.IsEmpty(smsDate) || TextUtils.IsEmpty(phoneNum.Text) || TextUtils.IsEmpty(smsCustomer.Text)
                    || TextUtils.IsEmpty(smsAddress.Text) || TextUtils.IsEmpty(smsCustNo.Text) || TextUtils.IsEmpty(smsOrderProd.Text)
                    || TextUtils.IsEmpty(smsProdQty.Text) || TextUtils.IsEmpty(smsUnit.Text) || TextUtils.IsEmpty(smsAgentName.Text))
                {
                    new Thread(new ThreadStart(delegate
                    {
                        RunOnUiThread(() => Toast.MakeText(this, "Please fill out all the fields", ToastLength.Long).Show());
                        RunOnUiThread(() => progress.Hide());
                    })).Start();
                    //Toast.MakeText(this, "Please fill out all the fields", ToastLength.Short).Show();
                    return;
                }
                else
                {
                    var phone = phoneNum.Text;
                    var message = smsDate + "|" + smsCustomer.Text + "|" + smsAddress.Text + "|" + smsCustNo.Text
                                  + "|" + smsOrderProd.Text + "|" + smsProdQty.Text + "|" + smsUnit.Text + "|" + smsAgentName.Text;

                    var piSent = PendingIntent.GetBroadcast(this, 0, new Intent("SMS_SENT"), 0);
                    var piDelivered = PendingIntent.GetBroadcast(this, 0, new Intent("SMS_DELIVERED"), 0);

                    if ((int)Build.VERSION.SdkInt < 23)
                    {
                        //spinner.Visibility = (ViewStates.Visible);
                        _smsManager.SendTextMessage(phone, null, message, piSent, piDelivered);
                        new Thread(new ThreadStart(delegate
                        {
                            RunOnUiThread(() => Toast.MakeText(this, "Sending Orders error! please restart the app", ToastLength.Long).Show());
                            RunOnUiThread(() => progress.Hide());
                        })).Start();
                        //Toast.MakeText(this, "Sending Orders error! please restart the app", ToastLength.Short).Show();
                        return;
                    }
                    else
                    {
                        if (ActivityCompat.CheckSelfPermission(this, Manifest.Permission.SendSms) != (int)Permission.Granted)
                        {
                            // Permission is not granted. If necessary display rationale & request.
                            RequestSendSMSPermission();
                            //new Thread(new ThreadStart(delegate
                            //{
                            //    //RequestSendSMSPermission();
                            //    RunOnUiThread(() => progress.Hide());
                            //})).Start();
                        }
                        else
                        {
                            // We have permission, go ahead and send SMS.
                            //spinner.Visibility = (ViewStates.Visible);
                            _smsManager.SendTextMessage(phone, null, message, piSent, piDelivered);
                            //new Thread(new ThreadStart(delegate
                            //{
                            //    //_smsManager.SendTextMessage(phone, null, message, piSent, piDelivered);
                            //    RunOnUiThread(() => progress.Hide());
                            //})).Start();

                        }
                    }


                }

                //_smsManager.SendTextMessage(phone, null, message, piSent, piDelivered);
            };

        }
        public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Android.Content.PM.Permission[] grantResults)
        {
            Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults);
            base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
        }
        public void RequestSendSMSPermission()
        {
            Log.Info("MainActivity", "Message permission has NOT been granted. Requesting permission.");
            if (ActivityCompat.ShouldShowRequestPermissionRationale(this, Manifest.Permission.SendSms))
            {
                Log.Info("MainActivity", "Displaying message permission rationale to provide additional context.");
                Snackbar.Make(layout, "Message permission is needed to send SMS.",
                    Snackbar.LengthIndefinite).SetAction("OK", new Action<View>(delegate (View obj) {
                        ActivityCompat.RequestPermissions(this, new String[] { Manifest.Permission.SendSms }, REQUEST_SENDSMS);
                    })).Show();
            }
            else
            {
                ActivityCompat.RequestPermissions(this, new String[] { Manifest.Permission.SendSms }, REQUEST_SENDSMS);
            }
        }
        //protected override void OnPause()
        //{
        //    base.OnPause();
        //    UnregisterReceiver(receiver);
        //}
        protected override void OnResume()
        {

            //spinner.Visibility = (ViewStates.Gone);
            base.OnResume();
            //spinner.setVisibility(View.GONE);

            _smsSentBroadcastReceiver = new SMSSentReceiver();
            _smsDeliveredBroadcastReceiver = new SMSDeliveredReceiver();

            RegisterReceiver(_smsSentBroadcastReceiver, new IntentFilter("SMS_SENT"));
            RegisterReceiver(_smsDeliveredBroadcastReceiver, new IntentFilter("SMS_DELIVERED"));
            //spinner.setVisibility(View.GONE);
        }

        protected override void OnPause()
        {
            base.OnPause();

            UnregisterReceiver(_smsSentBroadcastReceiver);
            UnregisterReceiver(_smsDeliveredBroadcastReceiver);
        }
        //[BroadcastReceiver(Exported = true, Permission = "//receiver/@android:android.permission.SEND_SMS")]
        [BroadcastReceiver]
        public class SMSSentReceiver : BroadcastReceiver
        {
            public override void OnReceive(Context context, Intent intent)
            {
                switch ((int)ResultCode)
                {
                    case (int)Result.Ok:
                        Toast.MakeText(Application.Context, "SMS has been sent", ToastLength.Short).Show();
                        progress.Hide();
                        break;
                    case (int)SmsResultError.GenericFailure:
                        Toast.MakeText(Application.Context, "Generic Failure", ToastLength.Short).Show();
                        progress.Hide();
                        break;
                    case (int)SmsResultError.NoService:
                        Toast.MakeText(Application.Context, "No Service", ToastLength.Short).Show();
                        progress.Hide();
                        break;
                    case (int)SmsResultError.NullPdu:
                        Toast.MakeText(Application.Context, "Null PDU", ToastLength.Short).Show();
                        progress.Hide();
                        break;
                    case (int)SmsResultError.RadioOff:
                        Toast.MakeText(Application.Context, "Radio Off", ToastLength.Short).Show();
                        progress.Hide();
                        break;
                    default:
                        break;
                }
            }

        }
        //[BroadcastReceiver(Exported = true, Permission = "//receiver/@android:android.permission.SEND_SMS")]
        [BroadcastReceiver]
        public class SMSDeliveredReceiver : BroadcastReceiver
        {
            public override void OnReceive(Context context, Intent intent)
            {
                switch ((int)ResultCode)
                {
                    case (int)Result.Ok:
                        Toast.MakeText(Application.Context, "SMS Delivered", ToastLength.Short).Show();
                        progress.Hide();
                        break;
                    case (int)Result.Canceled:
                        Toast.MakeText(Application.Context, "SMS not delivered", ToastLength.Short).Show();
                        progress.Hide();
                        break;
                }
            }
        }
    }
}

使用Android.App；
使用Android.OS；
使用Android.Support.V7.App；
使用Android.Runtime；
使用Android.Widget；
使用Android.Content.PM；
使用Android.Telephony；
使用制度；
使用安卓系统；
使用Android.Content；
使用Android.Support.V4.Content；
使用Android.Support.V4.App；
使用Android.Util；
使用Android.Support.Design.Widget；
使用Android.Views；
使用Android.Text；
使用系统线程；
名称空间MhylesOrderingApp
{
[活动（Label=“@string/app_name”，Theme=“@style/AppTheme”，MainLauncher=true）]
公共类MainActivity:AppCompativeActivity、ActivityCompat.IOnRequestPermissionsResultCallback
{
静态只读int请求\u SENDSMS=0；
私有SmsManager_SmsManager；
专用广播接收器_smsSentBroadcastReceiver，_smsDeliveredBroadcastReceiver；
视图布局；
//私人旋转棒；
静态Android.App.ProgressDialog进程；
//Android.App.ProgressDialog.progress；
//公共虚拟视图状态可见性{get；set；}
//SMS中央接收机；
//私有SmsManager SmsManager；
创建时受保护的覆盖无效（Bundle savedInstanceState）
{
base.OnCreate（savedInstanceState）；
//从“主”布局资源设置视图
SetContentView（Resource.Layout.activity_main）；
布局=FindViewById（Resource.Id.sample\u main\u布局）；
//微调器=（ProgressBar）FindViewById（Resource.Id.progressBar1）；
var smsBtn=findviewbyd（Resource.Id.btnSend）；
var phoneNum=findviewbyd（Resource.Id.phoneNum）；
var smsDate=“”；
var smsCustomer=findviewbyd（Resource.Id.txtCustomer）；
var smsAddress=findviewbyd（Resource.Id.txtAddress）；
var smsCustNo=findviewbyd（Resource.Id.txtCustomerNo）；
var smsOrderProd=FindViewById（Resource.Id.txtOrderedProduct）；
var smsProdQty=findviewbyd（Resource.Id.txtProductQty）；
var smsUnit=findviewbyd（Resource.Id.txtnit）；
var smsAgentName=findviewbyd（Resource.Id.txtAgentName）；
var scrollView=findviewbyd（Resource.Id.scrollView）；
DateTime now=DateTime.now.ToLocalTime（）；
smsDate=now.ToString（）；
scrollView.SetBackgroundResource（Resource.Drawable.TextViewStyle）；
SetBackgroundResource（Resource.Drawable.EditTextStyle）；
smsCustomer.SetBackgroundResource（Resource.Drawable.EditTextStyle）；
smsAddress.SetBackgroundResource（Resource.Drawable.EditTextStyle）；
smsCustNo.SetBackgroundResource（Resource.Drawable.EditTextStyle）；
smsOrderProd.SetBackgroundResource（Resource.Drawable.EditTextStyle）；
smsProdQty.SetBackgroundResource（Resource.Drawable.EditTextStyle）；
SetBackgroundResource（Resource.Drawable.EditTextStyle）；
smsAgentName.SetBackgroundResource（Resource.Drawable.EditTextStyle）；
//spinner.Visibility=（ViewStates.Gone）；
progress=newandroid.App.ProgressDialog（此对话框）；
进程。不确定=真；
progress.SetProgressStyle（Android.App.ProgressDialogStyle.Spinner）；
progress.SetMessage（“正在发送..请稍候！”）；
进度。可设置可取消（false）；
_smsManager=smsmsmanager.Default；
//接收器=新的SMSSentReceiver（）；
//smsManager=smsmsmanager.Default；
//IntentFilter IntentFilter=新的IntentFilter（“SMS_发送”）；
//intentFilter.AddAction（“android.permission.SEND_SMS”）；
////注册接收者（接收者、意图过滤器）；
//smsBtn.单击+=（s，e）=>
//{
//var phone=phoneNum.Text；
//var message=sms.Text；
//var piSent=pendingent.GetBroadcast（this，0，新的Android.Content.Intent（“SMS_SENT”），0）；
////var piDelivered=pendingent.GetBroadcast（this，0，新的Android.Content.Intent（“SMS_交付”），0）；
//smsManager.SendTextMessage（phone，null，message，piSent，null）；
//};
smsBtn.单击+=（s，e）=>
{
progress.Show（）；
if（TextUtils.IsEmpty（smsDate）| TextUtils.IsEmpty（phoneNum.Text）| TextUtils.IsEmpty（smsCustomer.Text）
||TextUtils.IsEmpty（smsAddress.Text）| | TextUtils.IsEmpty（smsCustNo.Text）| | TextUtils.IsEmpty（smsOrderProd.Text）
||TextUtils.IsEmpty（smsProdQty.Text）| | TextUtils.IsEmpty（smsUnit.Text）| | TextUtils.IsEmpty（smsAgentName.Text））
{
新线程（新线程开始（代理
{
RunOnUiThread（（）=>Toast.MakeText（这是“请填写所有字段”，ToastLength.Long）.Show（））；
RunOnUiThread（（）=>progress.Hide（））；
})).Start（）；
//Toast.MakeText（这是“请填写所有字段”，ToastLength.Short）.Show（）；
返回；
}
其他的
{
var phone=phoneNum.Text；
var message=smsDate+“|”+smsCustomer.Text+“|”+smsAddress.Text+“|”+smsCustNo.Text
+“|”+smsOrderProd.Text+“|”+smsProdQty.Text+“|”+smsUnit.Text+“|”+smsAgentName.Text；
 editText.Text = "";