Xamarin android在活动和从其他活动重置之间传递时间-Java 学习之路

我是 xamarin android的新手 . 我有一个重置时间的问题我希望将时间传递给 SeeTime 活动，并将该时间的重置时间重置为60，这也将重置 MainActivity 中的时间 .

public class MainActivity : AppCompatActivity
    {
       public EditText timer;
        Button btn;
        public int elapsedTime;    // counting values integer
        Handler myHandler;   // used to delay runnable for a second which delay_RATE
        int delay_RATE = 1000;    //delay
        Java.Lang.Runnable r;
        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);
            SetContentView(Resource.Layout.activity_main);
            elapsedTime = 60; // default value
            myHandler = new Handler();     //initializing handler
            r = new Java.Lang.Runnable(Run);
            timer = FindViewById<EditText>(Resource.Id.timertxt);
            btn = FindViewById<Button>(Resource.Id.btn1);
            btn.Click += Btn_Click;
            Counter();
        }

        private void Btn_Click(object sender, System.EventArgs e)
        {
            elapsedTime = 20;
            StartActivity(typeof(SeeTime));
        }

        void Counter()
        {
            elapsedTime--;      // increment
            timer.Text = elapsedTime.ToString();
            myHandler.PostDelayed(r, delay_RATE);
            if (elapsedTime == 0)
            {
                elapsedTime = 20;
            }
        }
        void Run()
        { Counter(); }

SeeTime Activity:

public class SeeTime : Activity
    {
        MainActivity mainActivity;
        private EditText timer;
        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);
            SetContentView(Resource.Layout.Time);
            timer = FindViewById<EditText>(Resource.Id.txtTime);
            mainActivity = new MainActivity();

            timer.Text = mainActivity.timer.Text;
            // Create your application here
        }
    }

1 回答

您可以尝试以下方法将 elapsedTime 从 MainActivity 传递给 SeeTime 活动 .

//主要活动

var intent = new Intent(this, typeof(SeeTime));
intent.PutExtra("Timer", elapsedTime);
StartActivity(intent);

// SeeTime acticity

int intValue = Intent.Extras.GetInt("Timer", 20);

此外，当您从 SeeTime 活动返回 MainActivity 时，可以使用 OnResume() 方法将 elapsedTime 重置为60.详细信息：https://docs.microsoft.com/en-us/xamarin/android/app-fundamentals/activity-lifecycle/

所以代码是这样的：

主要活动

using Android.App;
using Android.OS;
using Android.Support.V7.App;
using Android.Runtime;
using Android.Widget;
using Android.Content;

namespace App80
{
    [Activity(Label = "@string/app_name", Theme = "@style/AppTheme", MainLauncher = true)]
    public class MainActivity : AppCompatActivity
    {
        public EditText timer;
        Button btn;
        public int elapsedTime;    // counting values integer
        Handler myHandler;   // used to delay runnable for a second which delay_RATE
        int delay_RATE = 1000;    //delay
        Java.Lang.Runnable r;
        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);
            SetContentView(Resource.Layout.activity_main);
            elapsedTime = 60; // default value
            myHandler = new Handler();     //initializing handler
            r = new Java.Lang.Runnable(Run);
            timer = FindViewById<EditText>(Resource.Id.timertxt);
            btn = FindViewById<Button>(Resource.Id.btn1);
            btn.Click += Btn_Click;
            Counter();
        }

        protected override void OnResume()
        {
            base.OnResume();
            elapsedTime = 60;
            timer.Text = elapsedTime.ToString();
        }

        private void Btn_Click(object sender, System.EventArgs e)
        {
            var intent = new Intent(this, typeof(SeeTime));
            intent.PutExtra("Timer", elapsedTime);
            StartActivity(intent);

        }

        void Counter()
        {
            elapsedTime--;      // increment
            timer.Text = elapsedTime.ToString();
            myHandler.PostDelayed(r, delay_RATE);
            if (elapsedTime == 0)
            {
                elapsedTime = 20;
            }
        }
        void Run()
        { Counter(); }
    }
}

SeeTime活动：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;

namespace App80
{
    [Activity(Label = "SeeTime")]
    public class SeeTime : Activity
    {
        //MainActivity mainActivity;
        private EditText timer;
        protected override void OnCreate(Bundle savedInstanceState)
        {
            base.OnCreate(savedInstanceState);
            SetContentView(Resource.Layout.Time);
            timer = FindViewById<EditText>(Resource.Id.txtTime);

            int intValue = Intent.Extras.GetInt("Timer", 20);

            timer.Text = intValue.ToString();

        }

    }
}

回复于 2024-05-15T21:25:44+08:00

Xamarin android在活动和从其他活动重置之间传递时间

1 回答

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