如何解决Xamarin Android:自定义渲染器的自定义键盘存在问题-出现在控件下方,按键无法按下等
我正在创建具有自定义键盘的自定义控件。我遇到了几个问题。
我正在使用Visual Studio Community 2019,并且正在使用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,因此我从中创建一个派生类,称为TextBoxEntry。
我在MainPage.cs中以编程方式创建了所有控件,因此MainPage.xaml为空白(差不多)。
Android专用代码(即渲染器)被塞入MainActivity.cs。
最后,自定义键盘在Resources / xml / keyboard.xml下定义。
我无法解决这些问题(已解决5个问题中的3个):
-
为什么自定义渲染器的自定义键盘会出现在控件下方?
-
出现键盘时,我需要获取其高度,以便可以相应地修改scrollview尺寸。不幸的是,在ControlOnFocusChanged()[EditText.FocusChange事件处理程序]中执行此操作不起作用,因为在该时间点上,键盘仍未显示,因此其高度为0。或者我应该在其中进行操作其他事件吗? 应改用ViewTreeObserver.IOnGlobalLayoutListener。
-
键盘上的键不可按下。有时,键盘会隐藏起来。我想我按这些键时,实际输入会失去焦点。无论如何,我实际上在哪里出错?
-
scrollview的最后一列以及最后一行的TextBoxEntries被剪掉。再说一次,我不知道出了什么问题。 通过将“ margin”设置为1可以解决此问题。
-
在ControlOnFocusChange()内,a_height提供1280,而b_height提供342。scrollview占据整个屏幕的一半以上,但是其高度远非整个屏幕的一半。这两个以不同的单位显示吗? 根据Find our the default height of the controls in Xamarin Forms,似乎两个高地都使用不同的单位...好吧,可以通过一些转换来解决。
因此,这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,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,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(20,20,0);
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, 资源/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>
解决方法
为什么自定义渲染器的自定义键盘出现在控件下方?
将alignParentBottom
属性设置为true,以使我们的键盘从屏幕的底部可见。
android:layout_alignParentBottom="true"
键盘上的键不可按下。有时,键盘会隐藏起来。我想我按这些键时,实际输入会失去焦点。无论如何,我实际上在哪里出错?
为我们的键可以具有的两个状态定义一个状态选择器:正常(不按)和按true或false按下。
您可以从GitHub下载源文件。 https://github.com/WendyZang/CustomKeyboardXamarinForms
版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 dio@foxmail.com 举报,一经查实,本站将立刻删除。