How to auto-fit RadRichTextEditor

Environment

Product Version	Product	Author
2018.3.1016	RadRichTextEditor for WinForms	Desislava Yordanova

Description

This article aims to demonstrate a sample approach how to auto-fit the document in RadRichTextEditor so that the editor shows always the whole page.

Solution

It can be achieved by adjusting the scale factor programmatically in order to fit the page. Thus, by calculating a ratio between the size of the editor and the actual page size, you can use this ratio to set the ScaleFactor property:

Auto-Fit RadRichTextEditor

• C#
• VB.NET

        public RadForm1()
        {
            InitializeComponent(); 

            this.radRichTextEditor1.SizeChanged += radRichTextEditor1_SizeChanged;  
        }

        private void SacleEditor()
        {
            float ratio = (this.radRichTextEditor1.Size.Width - this.radRichTextEditor1.RichTextBoxElement.VerticalScrollBar.Size.Width - 5) 
                / (float)this.radRichTextEditor1.Document.SectionDefaultPageSize.Width;
            this.radRichTextEditor1.ScaleFactor = new System.Drawing.SizeF(ratio, ratio);
        }

        private void radRichTextEditor1_SizeChanged(object sender, EventArgs e)
        {
            SacleEditor();
        }

        private void radButton1_Click(object sender, EventArgs e)
        {
            Telerik.WinControls.RichTextEditor.UI.DocumentPrintLayoutPresenter presenter = 
                radRichTextEditor1.RichTextBoxElement.ActiveEditorPresenter as DocumentPrintLayoutPresenter;
            presenter.PagePresentersMargin = new Telerik.WinForms.Documents.Model.SizeF(0, 0);

            this.radRichTextEditor1.SizeChanged += radRichTextEditor1_SizeChanged;
            SacleEditor();
        }

     Public Sub New()
        InitializeComponent()
        AddHandler Me.RadRichTextEditor1.SizeChanged, AddressOf radRichTextEditor1_SizeChanged
    End Sub

    Private Sub SacleEditor()
        Dim ratio As Single = (Me.RadRichTextEditor1.Size.Width - Me.RadRichTextEditor1.RichTextBoxElement.VerticalScrollBar.Size.Width - 5) _
                              / CSng(Me.RadRichTextEditor1.Document.SectionDefaultPageSize.Width)
        Me.RadRichTextEditor1.ScaleFactor = New System.Drawing.SizeF(ratio, ratio)
    End Sub

    Private Sub radRichTextEditor1_SizeChanged(ByVal sender As Object, ByVal e As EventArgs)
        SacleEditor()
    End Sub

    Private Sub radButton1_Click(ByVal sender As Object, ByVal e As EventArgs)
        Dim presenter As Telerik.WinControls.RichTextEditor.UI.DocumentPrintLayoutPresenter = _
            TryCast(RadRichTextEditor1.RichTextBoxElement.ActiveEditorPresenter, DocumentPrintLayoutPresenter)
        presenter.PagePresentersMargin = New Telerik.WinForms.Documents.Model.SizeF(0, 0)
        AddHandler Me.RadRichTextEditor1.SizeChanged, AddressOf radRichTextEditor1_SizeChanged
        SacleEditor()
    End Sub

Now, you can resize the form and the document will fit the width: