wpf richtextbox in winforms application - wpf

Question

I would like to use a WPF RichTextBox in a WinForms project written with VB
I have created the WinForms project with one form and a button
I then added a new project WPF User Control Library placed a WPF RichTextBox on the WPF form
I added ElementHost interoperability to the WinForm with these Imports
Imports System
Imports System.Windows.Forms
Imports System.Windows.Forms.Integration
From here I am lost some of the SO question are 10 to 7 years old the MS tutorial is not much help
Code from WPF Form
Public Class UserControl1
ReadOnly rtbWPF As New UserControl
ElementHost
wpfwindow.Show
End Class
I did not post the XAML code NOT sure how to do that
So the question what to do next to link the WPF form with the RTB to the WinForms form?
I would like to load data from a SQLite DB into the WPF RichTextBox and save the text entered in the RTB into the DB

Answer 1

This answer is meant to expand on #KyleWang wonderful answer
One BIG issue with Vectors choice of the WPF RichTextBox is There is no Text property in the WPF RichTextBox control. Here is one way to get all of the text out. That said I would IMHO would suggest using the WPF Plain TextBox control
Vector also commented on how to hide the HotReload in the title bar
Tools > Options > Debugging > General > un-check Enable UI Debugging Tools for XAML
OK Code Below hope this is helpful if you decide to use a WPF control in WinForms for spell checking
Public Class frmStart
Dim rtb As Windows.Controls.RichTextBox = New Windows.Controls.RichTextBox()
Dim tb As Windows.Controls.TextBox = New Windows.Controls.TextBox()
Dim str As String = " "
Private Sub frmStart_Load(sender As Object, e As EventArgs) Handles MyBase.Load
ElementHost1.Child = rtb
rtb.SpellCheck.IsEnabled = True
ElementHost2.Child = tb
tb.SpellCheck.IsEnabled = True
If str.Length < 100 Then
rtb.VerticalScrollBarVisibility = Windows.Controls.ScrollBarVisibility.Visible
End If
End Sub
Private Sub btnAdd_Click(sender As Object, e As EventArgs) Handles btnAdd.Click
str = "Plain WPF TxtBox"
tb.Text = str
rtb.AppendText("Heree is som mispelled txt se if the dictioary wrks more nonsense to see the scroll bar's will this word wrapp or is that rapp")
End Sub
Private Sub btnGet_Click(sender As Object, e As EventArgs) Handles btnGet.Click
Dim elementHost = ElementHost1
Dim wpfRichText = CType(elementHost.Child, Windows.Controls.RichTextBox)
Dim range As Windows.Documents.TextRange = New Windows.Documents.TextRange(rtb.Document.ContentStart, rtb.Document.ContentEnd)
Dim allText As String = range.Text
tbMsg.Text = allText.ToString
End Sub
Private Sub btnGTB_Click(sender As Object, e As EventArgs) Handles btnGTB.Click
Dim elementHost = ElementHost2
Dim text = tb.Text
tbMsg.Text = text.ToString
End Sub

Answer 2

To host a WPF control in Winforms, you can refer to the following two ways.
First, both of them need to add a ElementHost control into form.
Solution A:
Directly declare the wpf controls (using Windows.Controls)
Dim rtb As Windows.Controls.RichTextBox = New Windows.Controls.RichTextBox()
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
rtb.SpellCheck.IsEnabled = True
ElementHost1.Child = rtb
End Sub
Solution B:
Create a new User Control(WPF) and edit the content in "UserControl1.xaml" as follows.
<Grid>
<RichTextBox x:Name="richtextbox" Foreground="Black" FontSize="24" Margin="0"></RichTextBox>
<RichTextBox SpellCheck.IsEnabled="True" />
</Grid>
Then modify the code in 'form1.vb'
Private uc As UserControl1 = New UserControl1()
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
ElementHost1.Child = uc
End Sub