根据鼠标状态和位置设置 Border.Brush 属性答案

【问题标题】：Set Border.Brush property according to Mouse State and Position根据鼠标状态和位置设置 Border.Brush 属性
【发布时间】：2020-01-13 20:41:16
【问题描述】：

我正在尝试更改我的 UserControl 的 Border.BorderBrush 属性，具体取决于鼠标是进入、离开还是在我的 UserControl 上按下。我已经尝试在后面的代码中明确地这样做，但是只要更改 Border.BorderBrush 属性，边框就会消失。

我尝试了一系列可能的解决方案，但均无济于事。在我当前的代码库中，我正在尝试使用 Style 和 Triggers 来为我管理它。我的问题是 IsMouseDown 没有属性，除非您正在处理一个 Button（至少这是我从阅读中收集到的），所以我为此定义了一个属性。

就在我认为它会起作用的时候，边框找不到我在 UserControl.Resources 中定义的 Style。

我已经用尽了我所知道的一切，任何帮助将不胜感激。

XAML：

<UserControl x:Class="OSK.Resources.Themes.Default.Key"
            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:local="clr-namespace:OSK.Resources.Themes.Default"
            mc:Ignorable="d"
            x:Name="OSKuwuDefaultKey"
            d:DesignHeight="48" d:DesignWidth="48">
<UserControl.Style>
    <Style x:Name="KeyStyle">
        <Style.Triggers>
            <Trigger Property="Border.IsMouseOver" Value="true">
                <Setter Property="Border.BorderBrush" Value="{Binding Path=BrushHover, RelativeSource={RelativeSource Self}}" />
            </Trigger>
            <Trigger Property="Border.IsMouseOver" Value="false">
                <Setter Property="Border.BorderBrush" Value="{Binding Path=BrushNormal, RelativeSource={RelativeSource Self}}" />
            </Trigger>
            <Trigger Property="local:Key.IsMouseDown" Value="true">
                <Setter Property="Border.BorderBrush" Value="{Binding Path=BrushDown, RelativeSource={RelativeSource Self}}" />
            </Trigger>
        </Style.Triggers>
    </Style>
</UserControl.Style>
<Border x:Name="key" Background="Transparent" Width="{Binding Path=Width, ElementName=OSKuwuDefaultKey}" Height="{Binding Path=Height, ElementName=OSKuwuDefaultKey}" BorderBrush="{Binding BorderBrush, ElementName=OSKuwuDefaultKey}" CornerRadius="{Binding Path=CornerRadius, ElementName=OSKuwuDefaultKey}" BorderThickness="{Binding Path=OutlineThickness, ElementName=OSKuwuDefaultKey}" MouseEnter="Key_MouseEnter" MouseLeave="Key_MouseLeave" MouseDown="Key_MouseDown" MouseUp="Key_MouseUp">
    <Canvas>
        <Label Content="{Binding SuperText, ElementName=OSKuwuDefaultKey}" Canvas.Top="6" Canvas.Left="8" />
        <Label Content="{Binding SubText, ElementName=OSKuwuDefaultKey}" Canvas.Top="20" Canvas.Right="4" />
    </Canvas>
</Border>

代码隐藏：

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

namespace OSK.Resources.Themes.Default
{
    /// <summary>
    /// Interaction logic for Key.xaml
    /// </summary>
    public partial class Key : UserControl
    {
        public static readonly DependencyProperty SuperTextProperty = DependencyProperty.Register("SuperText", typeof(string), typeof(Key), new FrameworkPropertyMetadata("", FrameworkPropertyMetadataOptions.AffectsRender));
        public string SuperText
        {
            get
            {
                return (string)GetValue(SuperTextProperty);
            }
            set
            {
                SetValue(SuperTextProperty, value);
            }
        }

        public static readonly DependencyProperty SubTextProperty = DependencyProperty.Register("SubText", typeof(string), typeof(Key), new FrameworkPropertyMetadata("", FrameworkPropertyMetadataOptions.AffectsRender));
        public string SubText
        {
            get
            {
                return (string)GetValue(SubTextProperty);
            }
            set
            {
                SetValue(SubTextProperty, value);
            }
        }

        public static readonly DependencyProperty BrushNormalProperty = DependencyProperty.Register("BrushNormal", typeof(Brush), typeof(Key), new FrameworkPropertyMetadata(Brushes.LightSlateGray));
        public Brush BrushNormal
        {
            get
            {
                return (Brush)GetValue(BrushNormalProperty);
            }
            set
            {
                SetValue(BrushNormalProperty, value);
            }
        }

        public static readonly DependencyProperty BrushHoverProperty = DependencyProperty.Register("BrushHover", typeof(Brush), typeof(Key), new FrameworkPropertyMetadata(Brushes.LightSteelBlue));
        public Brush BrushHover
        {
            get
            {
                return (Brush)GetValue(BrushHoverProperty);
            }
            set
            {
                SetValue(BrushHoverProperty, value);
            }
        }

        public static readonly DependencyProperty BrushDownProperty = DependencyProperty.Register("BrushDown", typeof(Brush), typeof(Key), new FrameworkPropertyMetadata(Brushes.SlateGray));
        public Brush BrushDown
        {
            get
            {
                return (Brush)GetValue(BrushDownProperty);
            }
            set
            {
                SetValue(BrushDownProperty, value);
            }
        }

        public static readonly DependencyProperty CornerRadiusProperty = DependencyProperty.Register("CornerRadius", typeof(int), typeof(Key), new FrameworkPropertyMetadata(4, FrameworkPropertyMetadataOptions.AffectsRender));
        public int CornerRadius
        {
            get
            {
                return (int)GetValue(CornerRadiusProperty);
            }
            set
            {
                SetValue(CornerRadiusProperty, value);
            }
        }

        public static readonly DependencyProperty OutlineThicknessProperty = DependencyProperty.Register("OutlineThickness", typeof(Thickness), typeof(Key), new FrameworkPropertyMetadata(new Thickness(1), FrameworkPropertyMetadataOptions.AffectsRender));
        public Thickness OutlineThickness
        {
            get
            {
                return (Thickness)GetValue(OutlineThicknessProperty);
            }
            set
            {
                SetValue(OutlineThicknessProperty, value);
            }
        }

        public static DependencyProperty IsMouseDownProperty = DependencyProperty.RegisterAttached("IsMouseDown", typeof(bool), typeof(Key), new FrameworkPropertyMetadata(default(bool)));
        public bool IsMouseDown
        {
            get
            {
                return (bool)GetValue(IsMouseDownProperty);
            }
            set
            {
                SetValue(IsMouseDownProperty, value);
            }
        }

        public Key()
        {
            InitializeComponent();
        }

        private void Key_MouseEnter(object sender, MouseEventArgs e)
        {
            //this.SetValue(Key.BorderBrushProperty, BrushNormal);
            //Console.WriteLine(GetValue(Key.BorderBrushProperty));
        }

        private void Key_MouseLeave(object sender, MouseEventArgs e)
        {
            //this.SetValue(Key.BorderBrushProperty, BrushHover);
        }

        private void Key_MouseDown(object sender, MouseButtonEventArgs e)
        {
            //this.SetValue(Key.BorderBrushProperty, BrushDown);
            this.SetValue(Key.IsMouseDownProperty, true);
        }

        private void Key_MouseUp(object sender, MouseButtonEventArgs e)
        {
            this.SetValue(Key.IsMouseDownProperty, false);
        }
    }
}

【问题讨论】：

您可以直接分配样式，而不是将样式声明为资源：<UserControl.Style><Style ...>...</Style></UserControl.Style>。 Setter 中的绑定缺少适当的源对象，例如{Binding Path=BrushHover, RelativeSource={RelativeSource Self}}
@Clemens 实际上我确实也尝试过 UserControl.Style，但忘了注意这一点。我收到一条错误消息'Key' TargetType does not match type of element 'UserControl'. 所以我尝试将其更改为<local:Key.Style> 但后来我得到The member "Style" is not recognized or is not accessible.
@Clemens 我需要 TargetType Key 的原因是因为我需要访问我的 Key.IsMouseDown 属性。
您的依赖属性声明不完整。请看一下这个，尤其是实现“包装器”：docs.microsoft.com/en-us/dotnet/framework/wpf/advanced/…
@codechinchilla "a solid color" 应该是通常的Background="Transparent"，与默认的null 背景不同。

标签： c# wpf border mouse brush

【解决方案1】：

我让它工作了。原帖有最终的工作代码。

而且布局应该是这样的，没有明确设置Border的大小：

<Border x:Name="key" Background="Transparent" 
    BorderBrush="{Binding BorderBrush, ElementName=OSKuwuDefaultKey}"
    CornerRadius="{Binding CornerRadius, ElementName=OSKuwuDefaultKey}" 
    BorderThickness="{Binding OutlineThickness, ElementName=OSKuwuDefaultKey}"
    MouseEnter="Key_MouseEnter"
    MouseLeave="Key_MouseLeave"
    MouseDown="Key_MouseDown"
    MouseUp="Key_MouseUp">

    <Canvas>
        ...
    </Canvas>
</Border>

【讨论】：