MAUI Blazor Android 輸入框軟鍵盤遮擋問題

前言

最近才發現MAUI Blazor Android存在輸入框軟鍵盤遮擋這個問題，搜索了一番，原來這是安卓webview一個由來已久的問題，還好有大佬提出瞭解決方案 AndroidBug5497Workaround，但是這是Java代碼，MAUI中需要做一些小的修改，修改一些方法名還有類的明確引用。廢話不多說，直接上代碼。

解決方案

第一步

將下麵的代碼添加到Platforms/Android文件夾中，註意using ，一個也不能少，我最開始就是因為缺少using Rect = Android.Graphics.Rect;沒有成功。命名空間也別忘了更改。

using Android.App;
using Android.Widget;
using static Android.Resource;
using Rect = Android.Graphics.Rect;
using View = Android.Views.View;

namespace MauiApp3.Platforms.Android
{
    public class AndroidBug5497Workaround
    {

        // For more information, see https://code.google.com/p/android/issues/detail?id=5497
        // To use this class, simply invoke assistActivity() on an Activity that already has its content view set.

        public static void AssistActivity(Activity activity)
        {
            new AndroidBug5497Workaround(activity);
        }

        private View mChildOfContent;
        private int usableHeightPrevious;
        private FrameLayout.LayoutParams frameLayoutParams;

        private AndroidBug5497Workaround(Activity activity)
        {
            FrameLayout content = (FrameLayout)activity.FindViewById(Id.Content);
            mChildOfContent = content.GetChildAt(0);
            mChildOfContent.ViewTreeObserver.GlobalLayout += (s, o) => PossiblyResizeChildOfContent();
            frameLayoutParams = (FrameLayout.LayoutParams)mChildOfContent.LayoutParameters;
        }

        private void PossiblyResizeChildOfContent()
        {
            int usableHeightNow = ComputeUsableHeight();
            if (usableHeightNow != usableHeightPrevious)
            {
                int usableHeightSansKeyboard = mChildOfContent.RootView.Height;
                int heightDifference = usableHeightSansKeyboard - usableHeightNow;
                if (heightDifference > (usableHeightSansKeyboard / 4))
                {
                    // keyboard probably just became visible
                    frameLayoutParams.Height = usableHeightSansKeyboard - heightDifference;
                }
                else
                {
                    // keyboard probably just became hidden
                    frameLayoutParams.Height = usableHeightSansKeyboard;
                }
                mChildOfContent.RequestLayout();
                usableHeightPrevious = usableHeightNow;
            }
        }

        private int ComputeUsableHeight()
        {
            Rect r = new Rect();
            mChildOfContent.GetWindowVisibleDisplayFrame(r);
            return (int)(r.Bottom - r.Top);// 全屏模式下： return r.bottom
        }

    }
}

第二步

Platforms/Android/MainActivity.cs中添加以下代碼

protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        AndroidBug5497Workaround.AssistActivity(this);
    }

後記

網上還有一些其他人針對底部導航欄和華為的修複，貌似加的也不多，參考著改改就能用了