WPF建立不規則窗體時WebBrowser控制元件不顯示的問題

zhaotianff發表於2024-09-11
Web控制元件

最近有小夥伴需要在不規則窗體上放置WebBrowser控制元件，因為設定了WindowStyle="None" 和 AllowsTransparency="True"。

導致WebBrowser控制元件不顯示。

介面程式碼如下所示：

 1 <Window x:Class="WebBrowserDemo.MainWindow"     
 3         xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 4         xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"   xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
 5         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
 6         xmlns:local="clr-namespace:WebBrowserDemo"
 7         mc:Ignorable="d"
 8         Height="979" Width="1259"
 9         WindowStyle="None" ResizeMode="NoResize" Background="Transparent" AllowsTransparency="True"
10         MouseLeftButtonDown="Window_MouseLeftButtonDown" Loaded="Window_Loaded">
11     <Canvas>
12         <Image Source="background.png" Stretch="Fill" Width="1259" Height="979" />
13         <WebBrowser x:Name="webBrowser" Width="521" Height="635" Canvas.Left="58" Canvas.Top="198" Address="https://www.baidu.com" HorizontalAlignment="Left" VerticalAlignment="Center"></cef:ChromiumWebBrowser>
14     </Canvas>
15 </Window>

預期效果如下：

但實際瀏覽器並不會顯示出來。

導致這個問題的原因是因為空域(airspace)問題，因為WebBrowser並不是一個原生的WPF控制元件，而是一個Win32控制元件。

詳細描述可以參考以下兩個連結：

https://learn.microsoft.com/en-us/archive/blogs/changov/webbrowser-control-on-transparent-wpf-window

https://learn.microsoft.com/en-us/dotnet/desktop/wpf/advanced/technology-regions-overview?view=netframeworkdesktop-4.8&redirectedfrom=MSDN

這裡提供三個解決辦法

1、將WebBrowser控制元件替換為CefSharp/WebView2等控制元件

這種方法最簡單，幾乎不用修改什麼程式碼，缺點是老版本系統可能不相容。

2、使用WindowsChrome

1 <WindowChrome.WindowChrome>
2        <WindowChrome GlassFrameThickness="-1"/>
3 </WindowChrome.WindowChrome>

需要配合 ResizeMode="CanMinimize" Background="Transparent" WindowStyle="None" 使用

完整介面程式碼如下：

 1 <Window x:Class="WebBrowserDemo.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:WebBrowserDemo"
 7         mc:Ignorable="d"
 8         ResizeMode="CanMinimize" Background="Transparent" WindowStyle="None" Height="979" Width="1259">
 9     <WindowChrome.WindowChrome>
10         <WindowChrome GlassFrameThickness="-1"/>
11     </WindowChrome.WindowChrome>
12     <Canvas>
13         <Canvas.Background>
14             <ImageBrush ImageSource="background.png" Stretch="Uniform"></ImageBrush>
15         </Canvas.Background>
16         <WebBrowser x:Name="webBrowser" Width="527" Height="501" Canvas.Left="54" Canvas.Top="249" Source="https://bing.com" HorizontalAlignment="Center" VerticalAlignment="Top"></WebBrowser>
17     </Canvas>
18 </Window>

3、將WebBrowser封裝到一個獨立的視窗，變成獨立控制元件

這個方法來自stackoverflow上的一個老哥，連結如下：

https://stackoverflow.com/questions/23529824/how-do-i-work-around-the-activex-webbrowser-flaw-in-a-wpf-window-that-allowstran

  • 首先我們新建一個Window

WebBrowserEx.xaml

 1 <Window x:Class="WebBrowserDemo.Controls.WebBrowserEx"
 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:WebBrowserDemo.Controls"
 7         xmlns:winForms="clr-namespace:System.Windows.Forms;assembly=System.Windows.Forms"     
 8         WindowStyle="None"
 9         ShowInTaskbar="False"
10         ResizeMode="NoResize"  Width="761" Height="444">
11     <WindowsFormsHost x:Name="wfh">
12         <winForms:WebBrowser x:Name="wfBrowser" />
13     </WindowsFormsHost>
14 </Window>

  • 後臺程式碼如下

WebBrowserEx.xaml.cs

  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.Shapes;
 14 
 15 namespace WebBrowserDemo.Controls
 16 {
 17     public partial class WebBrowserEx : Window
 18     {
 19         public WebBrowserEx()
 20         {
 21             InitializeComponent();
 22         }
 23 
 24         public static readonly DependencyProperty TargetElementProperty = DependencyProperty.Register("TargetElement", typeof(FrameworkElement), typeof(WebBrowserEx), new PropertyMetadata(TargetElementPropertyChanged));
 25         public FrameworkElement TargetElement
 26         {
 27             get
 28             {
 29                 return GetValue(TargetElementProperty) as FrameworkElement;
 30             }
 31             set
 32             {
 33                 SetValue(TargetElementProperty, value);
 34             }
 35         }
 36 
 37 
 38         public static readonly DependencyProperty SourceProperty = DependencyProperty.Register("Source", typeof(string), typeof(WebBrowserEx), new PropertyMetadata(SourcePropertyChanged));
 39         public string Source
 40         {
 41             get
 42             {
 43                 return GetValue(SourceProperty) as string;
 44             }
 45             set
 46             {
 47                 SetValue(SourceProperty, value);
 48             }
 49         }
 50         private static void SourcePropertyChanged(DependencyObject sender, DependencyPropertyChangedEventArgs args)
 51         {
 52             var webBrowserOverlayWindow = sender as WebBrowserEx;
 53 
 54             if (webBrowserOverlayWindow != null)
 55             {
 56                 webBrowserOverlayWindow.wfBrowser.Navigate(args.NewValue as string);
 57             }
 58         }
 59 
 60         private static void TargetElementPropertyChanged(DependencyObject sender, DependencyPropertyChangedEventArgs args)
 61         {
 62             var oldTargetElement = args.OldValue as FrameworkElement;
 63             var webBrowserOverlayWindow = sender as WebBrowserEx;
 64             var mainWindow = Window.GetWindow(webBrowserOverlayWindow.TargetElement);
 65 
 66             if (webBrowserOverlayWindow != null && mainWindow != null)
 67             {
 68                 webBrowserOverlayWindow.Owner = mainWindow;
 69                 webBrowserOverlayWindow.Owner.LocationChanged += webBrowserOverlayWindow.PositionAndResize;
 70                 webBrowserOverlayWindow.TargetElement.LayoutUpdated += webBrowserOverlayWindow.PositionAndResize;
 71 
 72                 if (oldTargetElement != null)
 73                     oldTargetElement.LayoutUpdated -= webBrowserOverlayWindow.PositionAndResize;
 74 
 75                 webBrowserOverlayWindow.PositionAndResize(sender, new EventArgs());
 76 
 77                 if (webBrowserOverlayWindow.TargetElement.IsVisible && webBrowserOverlayWindow.Owner.IsVisible)
 78                 {
 79                     webBrowserOverlayWindow.Show();
 80                 }
 81 
 82                 webBrowserOverlayWindow.TargetElement.IsVisibleChanged += (x, y) =>
 83                 {
 84                     if (webBrowserOverlayWindow.TargetElement.IsVisible && webBrowserOverlayWindow.Owner.IsVisible)
 85                     {
 86                         webBrowserOverlayWindow.Show();
 87                     }
 88                     else
 89                     {
 90                         webBrowserOverlayWindow.Hide();
 91                     }
 92                 };
 93             }
 94         }
 95 
 96         protected override void OnClosed(EventArgs e)
 97         {
 98             base.OnClosed(e);
 99 
100             Owner.LocationChanged -= PositionAndResize;
101             if (TargetElement != null)
102             {
103                 TargetElement.LayoutUpdated -= PositionAndResize;
104             }
105         }
106 
107         private void PositionAndResize(object sender, EventArgs e)
108         {
109             if (TargetElement != null && TargetElement.IsVisible)
110             {
111                 var point = TargetElement.PointToScreen(new Point());
112                 Left = point.X + 396;  //這裡可以控制位置
113                 Top = point.Y + 326;   //point是左上角0,0的位置
114 
115                 //Height = TargetElement.ActualHeight;  //這裡可以控制寬高
116                 //Width = TargetElement.ActualWidth;
117             }
118         }
119 
120     }
121 }

  • 然後我們新建一個自定義控制元件

CustomWebBrowser.cs

 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 WebBrowserDemo.Controls
17 {
18     public class CustomWebBrowser : Control
19     {
20 
21         private WebBrowserEx _WebBrowserOverlayWindow;
22         public static readonly DependencyProperty TargetElementProperty = DependencyProperty.Register("TargetElement", typeof(FrameworkElement), typeof(CustomWebBrowser), new PropertyMetadata(TargetElementPropertyChanged));
23         public FrameworkElement TargetElement
24         {
25             get
26             {
27                 return GetValue(TargetElementProperty) as FrameworkElement;
28             }
29             set
30             {
31                 SetValue(TargetElementProperty, value);
32             }
33         }
34 
35         public static readonly DependencyProperty SourceProperty = DependencyProperty.Register("Source", typeof(string), typeof(CustomWebBrowser), new PropertyMetadata(SourcePropertyChanged));
36         public string Source
37         {
38             get
39             {
40                 return GetValue(SourceProperty) as string;
41             }
42             set
43             {
44                 SetValue(SourceProperty, value);
45             }
46         }
47 
48         private static void SourcePropertyChanged(DependencyObject sender, DependencyPropertyChangedEventArgs args)
49         {
50             var transparentWebBrowser = sender as CustomWebBrowser;
51             if (transparentWebBrowser != null)
52             {
53                 transparentWebBrowser._WebBrowserOverlayWindow.Source = args.NewValue as string;
54             }
55         }
56 
57         private static void TargetElementPropertyChanged(DependencyObject sender, DependencyPropertyChangedEventArgs args)
58         {
59             var transparentWebBrowser = sender as CustomWebBrowser;
60             if (transparentWebBrowser != null)
61             {
62                 transparentWebBrowser._WebBrowserOverlayWindow.TargetElement = args.NewValue as FrameworkElement;
63             }
64         }
65 
66         public CustomWebBrowser()
67         {
68             _WebBrowserOverlayWindow = new WebBrowserEx();
69         }
70 
71         static CustomWebBrowser()
72         {
73             DefaultStyleKeyProperty.OverrideMetadata(typeof(CustomWebBrowser), new FrameworkPropertyMetadata(typeof(CustomWebBrowser)));
74         }
75     }
76 }

  • 自定義控制元件樣式如下
 1  <Style TargetType="{x:Type local:CustomWebBrowser}">
 2      <Setter Property="Template">
 3          <Setter.Value>
 4              <ControlTemplate TargetType="{x:Type local:CustomWebBrowser}">
 5                  <Border Background="{TemplateBinding Background}"
 6                          BorderBrush="{TemplateBinding BorderBrush}"
 7                          BorderThickness="{TemplateBinding BorderThickness}">
 8                  </Border>
 9              </ControlTemplate>
10          </Setter.Value>
11      </Setter>
12  </Style>

  • 使用時將WebBrowser控制元件換成CustomWebBrowser即可。

示例程式碼

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