WPF 实现蒙板控件

Posted 2023-03-12 dotNET跨平台

 WPF 实现蒙板控件

控件名：Mask

作   者：WPFDevelopersOrg - 驚鏵

原文链接^[1]：https://github.com/WPFDevelopersOrg/WPFDevelopers

• 框架使用.NET40；

• Visual Studio 2022;

• 使用方式需引入命名空间后 wd:Mask.IsMask="true"，即可显示蒙板。

• 显示蒙板内容需 wd:Mask.Child 进行复赋值。

1）创建装饰 AdornerContainer 代码如下:

using System.Windows;
using System.Windows.Documents;
using System.Windows.Media;

namespace WPFDevelopers.Utilities

    public class AdornerContainer : Adorner
    
        private UIElement _child;
        public AdornerContainer(UIElement adornedElement) : base(adornedElement)
        
        
        public UIElement Child
        
            get => _child;
            set
            
                if (value == null)
                
                    RemoveVisualChild(_child);
                    _child = value;
                    return;
                
                AddVisualChild(value);
                _child = value;
            
        
        protected override int VisualChildrenCount
        
            get
            
                return _child != null ? 1 : 0;
            
        

        protected override Size ArrangeOverride(Size finalSize)
        
            _child?.Arrange(new Rect(finalSize));
            return finalSize;
        

        protected override Visual GetVisualChild(int index)
        
            if (index == 0 && _child != null) return _child;
            return base.GetVisualChild(index);
        
    

2）创建蒙板控件 MaskControl 代码如下:

using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;

namespace WPFDevelopers.Controls

    public class MaskControl : ContentControl
    
        private readonly Visual visual;
        public static readonly DependencyProperty CornerRadiusProperty =
          DependencyProperty.Register("CornerRadius", typeof(CornerRadius), typeof(MaskControl), 
              new PropertyMetadata(new CornerRadius(0)));
        public MaskControl(Visual _visual)
        
            visual = _visual;
        
        public CornerRadius CornerRadius
        
            get => (CornerRadius)GetValue(CornerRadiusProperty);
            set => SetValue(CornerRadiusProperty, value);
        
    

3）创建 Mask 继承 Control 增加附加属性 IsMask 代码如下:

• True 则动态添加装饰器 AdornerContainer 并将 MaskControl 添加到 AdornerContainer.Child 中。

• False 则移除装饰器。

using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using WPFDevelopers.Helpers;
using WPFDevelopers.Utilities;

namespace WPFDevelopers.Controls

    public class Mask : Control
    
        public object Child
        
            get  return (object)GetValue(ChildProperty); 
            set  SetValue(ChildProperty, value); 
        
        public static readonly DependencyProperty ChildProperty =
            DependencyProperty.Register("Child", typeof(object), typeof(Mask), new PropertyMetadata(null));


        public static object GetChild(UIElement element)
        
            if (element == null)  throw new ArgumentNullException("element"); 

            return (object)element.GetValue(ChildProperty);
        

        public static void SetChild(UIElement element, object child)
        
            if (element == null)  throw new ArgumentNullException("element"); 

            element.SetValue(ChildProperty, child);
        
        public static readonly DependencyProperty IsMaskProperty =
         DependencyProperty.RegisterAttached("IsMask", typeof(bool), typeof(Mask),
             new PropertyMetadata(false, OnIsMaskChanged));
        private static void OnIsMaskChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        
            PropertyChanged(d, e);
        
        static void PropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        
            if (e.NewValue is bool isMask && d is FrameworkElement parent)
            
                if (isMask)
                
                    if (!parent.IsLoaded)
                        parent.Loaded += Parent_Loaded;
                    else
                        CreateMask(parent);
                
                else
                
                    parent.Loaded -= Parent_Loaded;
                    CreateMask(parent, true);
                
            
        
        private static void Parent_Loaded(object sender, RoutedEventArgs e)
        
            if (sender is UIElement element)
                CreateMask(element);
        

        static void CreateMask(UIElement uIElement, bool isRemove = false)
        
            var _layer = AdornerLayer.GetAdornerLayer(uIElement);
            if (_layer == null) return;
            if (isRemove && uIElement != null)
            
                var adorners = _layer.GetAdorners(uIElement);
                if (adorners != null)
                
                    foreach (var item in adorners)
                    
                        if (item is AdornerContainer container)
                        
                            _layer.Remove(container);
                        
                    
                
                return;
            

            var _adornerContainer = new AdornerContainer(uIElement);
            var value = Mask.GetChild(uIElement);
             _adornerContainer.Child = new MaskControl(uIElement)  Content = value ;
            _layer.Add(_adornerContainer);

        
        public static bool GetIsMask(DependencyObject obj)
        
            return (bool)obj.GetValue(IsMaskProperty);
        

        public static void SetIsMask(DependencyObject obj, bool value)
        
            obj.SetValue(IsMaskProperty, value);
        
    

4）创建 Mask.xaml 代码如下:

<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                    xmlns:controls="clr-namespace:WPFDevelopers.Controls">

    <ResourceDictionary.MergedDictionaries>
        <ResourceDictionary Source="Basic/ControlBasic.xaml"/>
    </ResourceDictionary.MergedDictionaries>

    <Style TargetType="x:Type controls:MaskControl" BasedOn="StaticResource ControlBasicStyle">
        <Setter Property="HorizontalContentAlignment" Value="Center"/>
        <Setter Property="VerticalContentAlignment" Value="Center"/>
        <Setter Property="Background" Value="DynamicResource PrimaryTextSolidColorBrush"/>
        <Setter Property="Template">
            <Setter.Value>
                <ControlTemplate TargetType="x:Type controls:MaskControl">
                    <controls:SmallPanel>
                        <Border x:Name="PART_Border"
                                        BorderBrush="TemplateBinding BorderBrush" 
                                        BorderThickness="TemplateBinding BorderThickness" 
                                        Background="TemplateBinding Background"
                                        Height="TemplateBinding Height" 
                                        Width="TemplateBinding Height"
                                        CornerRadius="TemplateBinding CornerRadius"
                                        Opacity=".7"/>
                        <ContentPresenter Margin="TemplateBinding Padding"
                                                  VerticalAlignment="TemplateBinding VerticalContentAlignment"
                                                  HorizontalAlignment="TemplateBinding HorizontalContentAlignment"/>
                    </controls:SmallPanel>
                </ControlTemplate>
            </Setter.Value>
        </Setter>
    </Style>
</ResourceDictionary>

5）创建 MaskExample.xaml 实例代码如下:

<UserControl x:Class="WPFDevelopers.Samples.ExampleViews.MaskExample"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
             xmlns:wd="https://github.com/WPFDevelopersOrg/WPFDevelopers"
             xmlns:controls="clr-namespace:WPFDevelopers.Samples.Controls"
             xmlns:local="clr-namespace:WPFDevelopers.Samples.ExampleViews"
             mc:Ignorable="d" 
             d:DesignHeight="450" d:DesignWidth="800">
        <Grid Margin="10">
            
            <StackPanel>
                <ToggleButton Name="ToggleButtonMask"/>
                <Border Background="LawnGreen" Height="200"
                    wd:Mask.IsMask="Binding ElementName=ToggleButtonMask,Path=IsChecked"
                    Margin="10">
                    <wd:Mask.Child>
                        <Border>
                            <TextBox wd:ElementHelper.IsWatermark="True"
                                 wd:ElementHelper.Watermark="我是蒙板输入框"/>
                        </Border>
                    </wd:Mask.Child>
                    <Button Content="Mask" 
                        VerticalAlignment="Center" 
                        HorizontalAlignment="Center"/>
                </Border>
            </StackPanel>
        </Grid>
</UserControl>

参考资料

[1]

原文链接: https://github.com/WPFDevelopersOrg/WPFDevelopers