Update webbrowser sample (#173)

* Update webbrowser sample As per suggestions https://github.com/dotnet/winforms/issues/4443#issuecomment-759333446 Resolves dotnet/winforms#4443 * fixup! Update webbrowser sample * fixup! Update webbrowser sample * Update dotnet-desktop-guide/framework/winforms/controls/implement-two-way-com-between-dhtml-and-client.md Co-authored-by: Andy De George <[email protected]> Co-authored-by: Andy De George <[email protected]>
2026-09-04 00:56:03 +02:00 · 2021-01-27 14:21:32 -08:00
parent 232f1b91e2
commit 1fe35d6424
5 changed files with 62 additions and 32 deletions
@@ -38,19 +38,14 @@ The <xref:System.Windows.Forms.WebBrowser> control lets you implement two-way co
     [!code-csharp[System.Windows.Forms.WebBrowser.ObjectForScripting#3](~/samples/snippets/csharp/VS_Snippets_Winforms/System.Windows.Forms.WebBrowser.ObjectForScripting/CS/form1.cs#3)]
     [!code-vb[System.Windows.Forms.WebBrowser.ObjectForScripting#3](~/samples/snippets/visualbasic/VS_Snippets_Winforms/System.Windows.Forms.WebBrowser.ObjectForScripting/vb/form1.vb#3)]

-4. Set the <xref:System.Windows.Forms.WebBrowser.ObjectForScripting%2A> property in the form's constructor or a <xref:System.Windows.Forms.Form.Load> event handler.
+4. Set the <xref:System.Windows.Forms.WebBrowser.ObjectForScripting%2A> property in the form's constructor or override the <xref:System.Windows.Forms.Form.OnLoad%2A> method.

     The following code uses the form class itself for the scripting object.

-    > [!NOTE]
-    > Component Object Model (COM) must be able to access the scripting object. To make your form visible to COM, add the <xref:System.Runtime.InteropServices.ComVisibleAttribute> attribute to your form class.
-
     [!code-csharp[System.Windows.Forms.WebBrowser.ObjectForScripting#4](~/samples/snippets/csharp/VS_Snippets_Winforms/System.Windows.Forms.WebBrowser.ObjectForScripting/CS/form1.cs#4)]
     [!code-vb[System.Windows.Forms.WebBrowser.ObjectForScripting#4](~/samples/snippets/visualbasic/VS_Snippets_Winforms/System.Windows.Forms.WebBrowser.ObjectForScripting/vb/form1.vb#4)]

-5. Implement public properties or methods in your application code that your script code will use.
-
-     For example, if you use the form class for the scripting object, add the following code to your form class.
+5. Implement your scripting object.

     [!code-csharp[System.Windows.Forms.WebBrowser.ObjectForScripting#5](~/samples/snippets/csharp/VS_Snippets_Winforms/System.Windows.Forms.WebBrowser.ObjectForScripting/CS/form1.cs#5)]
     [!code-vb[System.Windows.Forms.WebBrowser.ObjectForScripting#5](~/samples/snippets/visualbasic/VS_Snippets_Winforms/System.Windows.Forms.WebBrowser.ObjectForScripting/vb/form1.vb#5)]
@@ -1,10 +1,7 @@
 //<snippet0>
 using System;
 using System.Windows.Forms;
-using System.Security.Permissions;

-[PermissionSet(SecurityAction.Demand, Name="FullTrust")]
-[System.Runtime.InteropServices.ComVisibleAttribute(true)]
 public class Form1 : Form
 {
    private WebBrowser webBrowser1 = new WebBrowser();
@@ -25,11 +22,12 @@ public class Form1 : Form
        webBrowser1.Dock = DockStyle.Fill;
        Controls.Add(webBrowser1);
        Controls.Add(button1);
-        Load += new EventHandler(Form1_Load);
    }

-    private void Form1_Load(object sender, EventArgs e)
+    protected override void OnLoad(EventArgs e)
    {
+        base.OnLoad(e);
+
        //<snippet1>
        webBrowser1.AllowWebBrowserDrop = false;
        //</snippet1>
@@ -40,7 +38,7 @@ public class Form1 : Form
        webBrowser1.WebBrowserShortcutsEnabled = false;
        //</snippet3>
        //<snippet4>
-        webBrowser1.ObjectForScripting = this;
+        webBrowser1.ObjectForScripting = new MyScriptObject(this);
        //</snippet4>
        //<snippet9>
        // Uncomment the following line when you are finished debugging.
@@ -56,13 +54,6 @@ public class Form1 : Form
            "</body></html>";
    }

-    //<snippet5>
-    public void Test(String message)
-    {
-        MessageBox.Show(message, "client code");
-    }
-    //</snippet5>
-
    private void button1_Click(object sender, EventArgs e)
    {
        //<snippet8>
@@ -71,4 +62,21 @@ public class Form1 : Form
        //</snippet8>
    }
 }
+
+//<snippet5>
+public class MyScriptObject
+{
+    private Form1 _form;
+
+    public MyScriptObject(Form1 form)
+    {
+        _form = form;
+    }
+
+    public void Test(string message)
+    {
+        MessageBox.Show(message, "client code");
+    }
+}
+//</snippet5>
 //</snippet0>
@@ -0,0 +1,9 @@
+<Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
+
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFrameworks>net472;netcoreapp3.1;net5.0-windows</TargetFrameworks>
+    <UseWindowsForms>true</UseWindowsForms>
+  </PropertyGroup>
+
+</Project>
@@ -1,9 +1,6 @@
 '<snippet0>
 Imports System.Windows.Forms
-Imports System.Security.Permissions

-<PermissionSet(SecurityAction.Demand, Name:="FullTrust")> _
-<System.Runtime.InteropServices.ComVisibleAttribute(True)> _
 Public Class Form1
    Inherits Form

@@ -24,8 +21,8 @@ Public Class Form1
        Controls.Add(button1)
    End Sub

-    Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) _
-        Handles Me.Load
+    Protected Overrides Sub OnLoad(e As EventArgs)
+        MyBase.OnLoad(e)

        '<snippet1>
        webBrowser1.AllowWebBrowserDrop = False
@@ -37,7 +34,7 @@ Public Class Form1
        webBrowser1.WebBrowserShortcutsEnabled = False
        '</snippet3>
        '<snippet4>
-        webBrowser1.ObjectForScripting = Me
+        webBrowser1.ObjectForScripting = New MyScriptObject(Me)
        '</snippet4>
        '<snippet9>
        ' Uncomment the following line when you are finished debugging.
@@ -53,12 +50,6 @@ Public Class Form1
            "</body></html>"
    End Sub

-    '<snippet5>
-    Public Sub Test(ByVal message As String)
-        MessageBox.Show(message, "client code")
-    End Sub
-    '</snippet5>
-
    Private Sub button1_Click(ByVal sender As Object, ByVal e As EventArgs) _
        Handles button1.Click

@@ -70,4 +61,19 @@ Public Class Form1
    End Sub

 End Class
+
+'<snippet5>
+Public Class MyScriptObject
+    Private _form As Form1
+
+    Public Sub New(ByVal form As Form1)
+        _form = form
+    End Sub
+
+    Public Sub Test(ByVal message As String)
+        MessageBox.Show(message, "client code")
+    End Sub
+
+End Class
+'</snippet5>
 '</snippet0>
@@ -0,0 +1,12 @@
+<Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">
+
+  <PropertyGroup>
+    <OutputType>WinExe</OutputType>
+    <TargetFrameworks>net472;net5.0-windows</TargetFrameworks>
+    <RootNamespace>sample</RootNamespace>
+    <UseWindowsForms>true</UseWindowsForms>
+    <MyType>WindowsForms</MyType>
+    <StartupObject>sample.Form1</StartupObject>
+  </PropertyGroup>
+
+</Project>