SteamTools/System.Common.ClientLib.Droid/Extensions/ActivityExtensions.cs

using Android.App;
using Android.OS;
using Android.Views.InputMethods;
using Android.Widget;
using AndroidX.Fragment.App;
using AndroidX.Navigation.Fragment;
using System.Diagnostics.CodeAnalysis;
using Fragment = AndroidX.Fragment.App.Fragment;

// ReSharper disable once CheckNamespace
namespace System
{
    /// <summary>
    /// <see cref="Activity"/> 扩展
    /// </summary>
    public static class ActivityExtensions
    {
        #region 显示隐藏软键盘 (Show/Hide)SoftInput

        /// <summary>
        /// 隐藏软键盘
        /// </summary>
        /// <param name="activity"></param>
        public static void HideSoftInput(this Activity activity)
        {
            var windowToken = (activity.CurrentFocus ?? activity.Window?.DecorView)?.WindowToken;
            if (windowToken != null)
            {
                var imm = activity.GetSystemService<InputMethodManager>();
                if (imm != null)
                {
                    imm.HideSoftInputFromWindow(windowToken, HideSoftInputFlags.NotAlways);
                }
            }
        }

        /// <summary>
        /// 显示软键盘
        /// </summary>
        /// <param name="activity"></param>
        /// <param name="editText"></param>
        /// <param name="inOnCreate">是否在<see cref="Activity.OnCreate(Android.OS.Bundle?)"/>中调用</param>
        public static void ShowSoftInput(this Activity activity, EditText editText, bool inOnCreate = false)
        {
            var imm = activity.GetSystemService<InputMethodManager>();
            if (imm != null)
            {
                if (inOnCreate)
                {
                    if (activity.Window != null)
                    {
                        activity.Window.DecorView.PostDelayed(ShowSoftInput, 100);
                    }
                    else
                    {
                        new Handler().PostDelayed(ShowSoftInput, 100);
                    }
                }
                else
                {
                    ShowSoftInput();
                }
                void ShowSoftInput()
                {
                    editText.Focusable = true;
                    editText.RequestFocus();
                    imm.ShowSoftInput(editText, 0);
                }
            }
        }

        #endregion

        #region 导航相关 AndroidX.Navigation

        /// <summary>
        /// 在 Activity 中 即时获取由 AndroidX.Navigation 管理的当前 Fragment
        /// </summary>
        /// <typeparam name="TFragment"></typeparam>
        /// <param name="activity"></param>
        /// <returns></returns>
        [return: MaybeNull]
        public static TFragment GetPrimaryNavigationFragment<TFragment>(
            this FragmentActivity activity)
            where TFragment : Fragment
        {
            var fragments = activity.SupportFragmentManager.Fragments;
            if (fragments != null)
            {
                foreach (var fragment in fragments)
                {
                    if (fragment is NavHostFragment navHostFragment)
                    {
                        var primaryNavigationFragment = navHostFragment
                            .ChildFragmentManager.PrimaryNavigationFragment;
                        if (primaryNavigationFragment is TFragment t)
                        {
                            return t;
                        }
                    }
                }
            }
            return null;
        }

        #endregion

        public static bool HasValue(this Activity? activity)
        {
            return activity != null && !activity.IsFinishing && !activity.IsDestroyed;
        }

#if DEBUG

        [Obsolete("use HasValue", true)]
        public static bool IsAvailable(this Activity? activity) => activity.HasValue();

#endif
    }
}