有的时候，给指定的控件，追加一个装饰器Adorner，备注下

有的时候，给指定的控件，追加一个装饰器Adorner，备注下

比如给某个图片加个工具条等等...都可以采用装饰器的方式来实现，复用性高，易维护，特此备注下

整体效果如下：

 1 <Window x:Class="AdornerDemo.MainWindow"
 2         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 3         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 4         xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
 5         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
 6         xmlns:local="clr-namespace:AdornerDemo"
 7         mc:Ignorable="d"
 8         WindowStartupLocation="CenterScreen"
 9         Title="MainWindow" Height="215.753" Width="467.123">
10     <Grid>
11         <TextBox x:Name="tb" Width="100" Height="40" />
12     </Grid>
13 </Window>

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 using System.Windows;
 7 using System.Windows.Controls;
 8 using System.Windows.Data;
 9 using System.Windows.Documents;
10 using System.Windows.Input;
11 using System.Windows.Media;
12 using System.Windows.Media.Imaging;
13 using System.Windows.Navigation;
14 using System.Windows.Shapes;
15
16 namespace AdornerDemo
17 {
18     /// <summary>
19     /// MainWindow.xaml 的交互逻辑
20     /// </summary>
21     public partial class MainWindow : Window
22     {
23         public MainWindow()
24         {
25             InitializeComponent();
26
27             Loaded += MainWindow_Loaded;
28         }
29
30         private void MainWindow_Loaded(object sender, RoutedEventArgs e)
31         {
32             var ad = AdornerLayer.GetAdornerLayer(tb);
33             ad.Add(new CustomAdorner(tb));
34         }
35     }
36 }

 1 using System;
 2 using System.Collections.Generic;
 3 using System.Linq;
 4 using System.Text;
 5 using System.Threading.Tasks;
 6 using System.Windows;
 7 using System.Windows.Controls;
 8 using System.Windows.Documents;
 9 using System.Windows.Input;
10 using System.Windows.Media;
11
12 namespace AdornerDemo
13 {
14     class CustomAdorner : Adorner
15     {
16         VisualCollection _visuals;
17         Canvas _canvas;
18         TextBlock block;
19
20         public CustomAdorner(UIElement adornedElement) : base(adornedElement)
21         {
22             _visuals = new VisualCollection(this);
23             block = new TextBlock();
24             block.Text = "√";
25             block.Cursor = Cursors.Hand;
26             block.MouseLeftButtonUp += Block_MouseLeftButtonUp;
27
28             _canvas = new Canvas();
29             _canvas.Children.Add(block);
30             _visuals.Add(_canvas);
31         }
32
33         private void Block_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
34         {
35             MessageBox.Show("xl");
36         }
37
38         protected override int VisualChildrenCount => _visuals.Count;
39
40         protected override Visual GetVisualChild(int index)
41         {
42             return _visuals[index];
43         }
44
45         protected override Size ArrangeOverride(Size finalSize)
46         {
47             _canvas.Arrange(new Rect(finalSize));
48             block.Margin = new Thickness(finalSize.Width + 3, 0, 0, 0);
49             return base.ArrangeOverride(finalSize);
50         }
51     }
52 }