Xamarin安卓系统：自定义渲染器的自定义键盘问题-出现在控件下方、按键不可按等

gjmwrych  于 2023-01-15  发布在  其他
关注(0)|答案(1)|浏览(148)

我正在创建一个具有自定义键盘的自定义控件。我遇到了几个问题。
我使用的是Visual Studio社区2019，并且使用Android_Accelerated_x86_Oreo（Android 8.1 API-27）作为我的Android模拟器。
总之，
我需要对Entry进行不同的样式设置，因此我从它创建了一个派生类，称为TextBoxEntry。
我在MainPage.cs中以编程方式创建了所有控件，因此MainPage.xaml是空的（差不多）。
Android特定代码（即渲染器）被塞进MainActivity.cs。
最后，定制键盘在Resources/xml/keyboard.xml下定义。
我无法解决这些问题（5个问题中的3个已解决）：
1.为什么自定义呈现器的自定义键盘显示在控件下面？
1.当键盘出现时，我需要得到它的高度，这样我就可以相应地修改滚动视图的尺寸。（）[EditText.FocusChange事件处理程序]不起作用，因为在那个时间点，键盘还没有显示，因此，它的高度为0。还是应该在其他事件中执行此操作？应该改用ViewTreeObserver. IOnGlobalLayoutListener。
1.键盘上的键是不可按的，有时候，键盘会隐藏起来，我猜当我按下键的时候，实际的输入就失去了焦点，不管怎么说，我实际上哪里出错了？
1.滚动视图的最后一列以及最后一行的TextBoxEntries被剪掉了。同样，我也不知道哪里出错了。这可以通过将margin设置为1来解决。
1.在ControlOnFocusChange（）中，a_height给出1280，而b_height给出342。滚动视图占据了整个屏幕的一半以上，但它的高度远远不到整个屏幕的一半。这两个视图是否以不同的单位显示？根据Find our the default height of the controls in Xamarin Forms，似乎两个Height使用不同的单位...好的，这个问题可以通过一些转换来解决。
下面是所有相关文件的内容：
MainPage.xaml:

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="CustomKeyboard.MainPage"/>

MainPage.xaml.cs:

using Xamarin.Forms;

namespace CustomKeyboard
{
    public class TextBoxEntry : Entry
    {
        public ScrollView ScrollView { get; set; } = null; // So that I could easily get its reference and work on it...
    }
    public partial class MainPage : ContentPage
    {
        AbsoluteLayout layout = null;
        ScrollView scrollview = null;
        Grid grid = null;

        public MainPage()
        {
            InitializeComponent();
            BuildControls();
            BuildTextBoxes();
        }
        private void BuildControls()
        {
            layout = new AbsoluteLayout();
            scrollview = new ScrollView();
            grid = new Grid();
            layout.Children.Add(scrollview, new Rectangle(0.5d, 0d, 0.95d, 0.85d), AbsoluteLayoutFlags.All);
            scrollview.BackgroundColor = Color.Yellow;
            scrollview.Padding = 5;
            scrollview.Content = grid;
            Content = layout;
        }
        private void BuildTextBoxes()
        {
            for (var i = 0; i < 50; ++i)
            {
                if (i % 5 == 0)
                {
                    var l = new Label()
                    {
                        Text = (i / 5).ToString(),
                        HorizontalTextAlignment = TextAlignment.Center,
                        VerticalTextAlignment = TextAlignment.Center,
                    };
                    grid.Children.Add(l, 0, i / 5);
                }
                else
                {
                    var r = i / 5;
                    var c = i % 5;
                    var e = new TextBoxEntry();
                    e.Margin = 1; // THIS SOLVES ISSUE 4
                    e.ScrollView = scrollview;
                    grid.Children.Add(e, c, r);
                }
            }
        }
    }
}

MainActivity.cs:

using Android.App;
using Android.Content;
using Android.Content.PM;
using Android.Graphics;
using Android.Graphics.Drawables;
using Android.InputMethodServices;
using Android.OS;
using Android.Support.Design.Widget;
using Android.Views;
using Android.Widget;

using Java.Lang;

using System.Threading.Tasks;

using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;
using Xamarin.Essentials;

using CustomKeyboard;
using CustomKeyboard.Droid;

[assembly: ExportRenderer(typeof(TextBoxEntry), typeof(TextBoxEntryRenderer))]

namespace CustomKeyboard.Droid
{
    [Activity(
        Label = "CustomKeyboard",
        Icon = "@mipmap/icon",
        Theme = "@style/MainTheme",
        MainLauncher = true,
        ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation
    )]

    public class MainActivity : FormsAppCompatActivity
    {
        internal static MainActivity Instance { get; private set; }
        protected override void OnCreate(Bundle savedInstanceState)
        {
            Instance = this;

            base.OnCreate(savedInstanceState);

            Xamarin.Essentials.Platform.Init(this, savedInstanceState);
            Forms.Init(this, savedInstanceState);
            LoadApplication(new App());
        }
    }

    public class TextBoxEntryRenderer : ViewRenderer<TextBoxEntry, TextInputLayout>
    {
        public KeyboardView mKeyboardView;
        ViewGroup activityRootView;
        protected EditText editText => Control.EditText;

        public TextBoxEntryRenderer(Context context) : base(context) { }

        protected override TextInputLayout CreateNativeControl()
        {
            #region Add keyboard
            var activity = MainActivity.Instance as Activity;
            activity.Window.SetSoftInputMode(SoftInput.StateAlwaysHidden);

            var rootView = activity.Window.DecorView.FindViewById(Android.Resource.Id.Content);
            activityRootView = ((ViewGroup)rootView).GetChildAt(0) as ViewGroup;

            mKeyboardView = new KeyboardView(MainActivity.Instance, null);
            mKeyboardView.PreviewEnabled = false; //Removes magnified key popups on key press
            mKeyboardView.Visibility = ViewStates.Gone;
            mKeyboardView.Keyboard = new Android.InputMethodServices.Keyboard(Context, Resource.Xml.keyboard);
            mKeyboardView.Key += (sender, e) =>
            {
                long eventTime = JavaSystem.CurrentTimeMillis();
                DispatchKeyEvent(new KeyEvent(eventTime, eventTime, KeyEventActions.Down, e.PrimaryCode, 0, 0, 0, 0, KeyEventFlags.SoftKeyboard | KeyEventFlags.KeepTouchMode));

                Task.Delay(1);
            };
            Android.Widget.RelativeLayout.LayoutParams layoutParams =
                new Android.Widget.RelativeLayout.LayoutParams(LayoutParams.MatchParent, LayoutParams.WrapContent); // or wrap_content
            layoutParams.AddRule(LayoutRules.AlignParentBottom);
            activityRootView.AddView(mKeyboardView, layoutParams);
            #endregion

            var _editText = new EditText(Context);
            _editText.SetTextColor(Android.Graphics.Color.Black);
            var textInputLayout = new TextInputLayout(Context);
            textInputLayout.AddView(_editText);
            return textInputLayout;
        }
        protected override void OnElementChanged(ElementChangedEventArgs<TextBoxEntry> e)
        {
            base.OnElementChanged(e);
            if (e.OldElement != null && Control != null) editText.FocusChange -= ControlOnFocusChange;
            if (e.NewElement != null)
            {
                SetNativeControl(CreateNativeControl());
                editText.ShowSoftInputOnFocus = false;
                editText.FocusChange += ControlOnFocusChange;
                editText.SetPadding(20, 0, 20, 0);
                editText.SetTextSize(Android.Util.ComplexUnitType.Px, 32);
                editText.TextChanged += (source, args) => { };
            }
            if (Control != null)
            {
                GradientDrawable gd = new GradientDrawable();
                gd.SetColor(Android.Graphics.Color.Transparent);
                Control.SetBackground(gd);
                editText.Background = null; // Remove underline.
                var shape = new ShapeDrawable(new Android.Graphics.Drawables.Shapes.RectShape());
                shape.Paint.Color = Xamarin.Forms.Color.Gray.ToAndroid();
                shape.Paint.SetStyle(Paint.Style.Stroke);
                Control.Background = shape;
            }
        }
        private void ControlOnFocusChange(object sender, FocusChangeEventArgs args)
        {
            if (args.HasFocus)
            {
                editText.Post(() =>
                {
                    editText.RequestFocus();
                    if (mKeyboardView.Visibility == ViewStates.Gone) mKeyboardView.Visibility = ViewStates.Visible;

                    // Wanna resize scrollview, but couldn't get necessary info...!
                    var deviceDisplayInfo = DeviceDisplay.MainDisplayInfo;
                    var a_height = deviceDisplayInfo.Height;
                    var b_height = Element.ScrollView.Height;
                    var c_height = mKeyboardView.Height;
                });
            }
            else
            {
                // Hide keyboard
                mKeyboardView.Visibility = ViewStates.Gone;
            }
        }
    }
}

最后，参考资料/xml/keyboard. xml：

<Keyboard xmlns:android="http://schemas.android.com/apk/res/android"
    android:keyWidth="25%p" android:horizontalGap="0px"
    android:verticalGap="0px" android:keyHeight="27dip">

  <Row>
    <Key android:codes="8"  android:keyLabel="1" android:keyHeight="54dip" android:keyEdgeFlags="left" />
    <Key android:codes="9"  android:keyLabel="2" android:keyHeight="54dip" />
    <Key android:codes="10" android:keyLabel="3" android:keyHeight="54dip" />
    <Key android:codes="81" android:keyLabel="+" android:keyHeight="81dip" android:keyEdgeFlags="right" />
  </Row>
  <Row></Row>
  <Row>
    <Key android:codes="11" android:keyLabel="4" android:keyHeight="54dip" android:keyEdgeFlags="left" />
    <Key android:codes="12" android:keyLabel="5" android:keyHeight="54dip" />
    <Key android:codes="13" android:keyLabel="6" android:keyHeight="54dip" />
  </Row>
  <Row>
    <Key android:codes="66" android:keyLabel="RET" android:keyHeight="81dip" android:horizontalGap="75%p" android:keyEdgeFlags="right" />
  </Row>
  <Row>
    <Key android:codes="14" android:keyLabel="7" android:keyHeight="54dip" android:keyEdgeFlags="left" />
    <Key android:codes="15" android:keyLabel="8" android:keyHeight="54dip" />
    <Key android:codes="16" android:keyLabel="9" android:keyHeight="54dip" />
  </Row>
  <Row></Row>
  <Row>
    <Key android:codes="17" android:keyLabel="*" android:keyHeight="54dip" android:keyEdgeFlags="left" />
    <Key android:codes="7"  android:keyLabel="0" android:keyHeight="54dip" />
    <Key android:codes="18" android:keyLabel="#" android:keyHeight="54dip" />
    <Key android:codes="67" android:keyLabel="DEL" android:keyHeight="54dip" android:keyEdgeFlags="right" />
  </Row>
  <Row></Row>

</Keyboard>
xamarin

1条答案

按热度按时间
uklbhaso

uklbhaso1#

为什么自定义呈现器的自定义键盘显示在控件下面？
将alignParentBottom属性设置为true，使键盘从屏幕底部可见。

android:layout_alignParentBottom="true"

键盘上的键是不可按的，有时候，键盘会隐藏起来，我猜当我按下键的时候，实际的输入就失去了焦点，不管怎么说，我实际上哪里出错了？
定义一个状态选择器，用于我们的键可以具有的两种状态：正常（未按下）和按下（正确或错误）。

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