Question

我一直在各种链接上闲聊，我无法判断我是否需要DependencyProperty，INotifyPropertyChanged，某种绑定或其他东西。

我正在使用我的第一个UserControl进行重复使用。我有一个UserControl包含一个标签和一个彩色椭圆。我希望能够在设计时在Windows XAML中设置椭圆颜色。我在Visual Studio 2013社区中有以下代码：

<UserControl x:Class="DMS2.LegendLabel"
         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" 
         mc:Ignorable="d">
<StackPanel Orientation="Horizontal">
    <Ellipse Name="Indicator" Height="10" Width="10" Margin="5" Fill="Aqua"/>
    <Label> value </Label>
</StackPanel>

namespace DMS2
{
    public partial class LegendLabel : UserControl
    {      
        public LegendLabel()
        {
            InitializeComponent();
        }

        private Brush ellipse_color = Brushes.Azure;

        public Brush LegendColor
        {
            get { return ellipse_color;  }
            set { ellipse_color = value; Indicator.Fill = ellipse_color; }
        }
    }
}


<Window x:Class="DMS2.ReportMonitor"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:custom_controls="clr-namespace:DMS2"
        Title="Report Monitor" Height="450" Width="850">
    <StackPanel Orientation="Vertical" Name="MainPanel">

        <StackPanel Orientation="Horizontal" Name="ButtonPanel">
            <Button Height="25" Margin="30,0"> Refresh List</Button>
            <CheckBox Margin="10"> show Reports From All Users</CheckBox>
            <Grid Margin="10" Width="300">
                <Grid.ColumnDefinitions>
                    <ColumnDefinition Width="*"/>
                    <ColumnDefinition Width="*"/>
                    <ColumnDefinition Width="*"/>
                </Grid.ColumnDefinitions>
                <Grid.RowDefinitions>
                    <RowDefinition />
                    <RowDefinition />
                </Grid.RowDefinitions>
                <custom_controls:LegendLabel LegendColor="Red">Pending</custom_controls:LegendLabel>
                <custom_controls:LegendLabel Grid.Column="1" LegendColor="Green">Viewed</custom_controls:LegendLabel>
                <custom_controls:LegendLabel Grid.Column="2" LegendColor="Blue">Active</custom_controls:LegendLabel>
                <Label Grid.Row="1">Done</Label>
                <Label Grid.Column="1" Grid.Row="1">Error</Label>
                <Label Grid.Column="2" Grid.Row="2">Closed</Label>
            </Grid>
            <Button Height="25" Margin="30,0">Close</Button>

        </StackPanel>

    </StackPanel>
</Window>

使用如下所示的LegendColor现已生效。我该如何进行以下工作？

<custom_controls:LegendLabel LegendColor="Red">Pending</custom_controls:LegendLabel>

Answer 1

是的，您通常会在此处使用DependencyProperty（代码段：propdp）。

    public Brush LegendColor
    {
        get { return (Brush)GetValue(LegendColorProperty); }
        set { SetValue(LegendColorProperty, value); }
    }

    // Using a DependencyProperty as the backing store for Value.  This enables animation, styling, binding, etc...
    public static readonly DependencyProperty LegendColorProperty =
        DependencyProperty.Register("LegendColor", typeof(Brush), typeof(LegendLabel), new PropertyMetadata(null, HandleBrushChange));

获得它之后，您将在PropertyChanged处理程序（元数据的第二个参数）中执行您的集合：

private static void HandleBrushChange(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
   LegendLabel local = (LegendLabel)d;

   local.Indicator.Fill = e.NewValue as Brush;
}

如何让我的自定义UserControl设置嵌套椭圆的颜色？

1 个答案: