Migrating From ActiveX

Applications written with TX Text Control ActiveX in Visual Basic 6 or another COM environment move to .NET with TX Text Control .NET for Windows Forms. Most members have a .NET counterpart, but the programming interface is organized differently: the long list of properties, methods and events of the ActiveX control is spread over classes such as Selection, ParagraphFormat and a collection for each kind of document object. The tables below name the .NET replacement of every ActiveX member, grouped by category, followed by the tool bars and the members that .NET doesn't need.

How the .NET Interface Differs

Most ActiveX members map to a .NET member with a similar name. The patterns below explain the rest:

• Formatting belongs to classes. Character formatting of the current selection is set through Selection, so FontBold becomes Selection.Bold. Paragraph attributes such as Alignment and the indents are properties of ParagraphFormat, and page, column and section settings are properties of PageMargins and SectionFormat. Because a class applies its attributes in one step, LockWindowUpdate is no longer needed.
• Document elements are objects in collections. Images, text frames, text fields, tables, sections, headers and footers and editable regions each have a class and a collection. The ActiveX ...Insert and ...Delete methods become Add and Remove of the collection, the ...AtInputPos properties become GetItem, and the ...Next methods become a foreach loop. Properties that selected the "current" object, such as FieldCurrent or ObjectCurrent, disappear: you set the properties of the object itself.
• Events are named in the past tense. CharFormatChange becomes CharFormatChanged, ParagraphFormatChange becomes ParagraphFormatChanged, and PosChange becomes InputPositionChanged.
• Standard control members come from Windows Forms. TextControl, ButtonBar, RulerBar and StatusBar derive from the Windows Forms class Control. Members such as Click, KeyDown, Font, Enabled and Handle are inherited from it, so the tables show them in code without a link to the TX Text Control reference.
• Errors are exceptions. The ActiveX Error event has no counterpart: .NET methods throw exceptions, as Exceptions and Error Handling describes.
• Server-side automation uses ServerTextControl. Where an ActiveX application called EnableAutomationServer, a .NET application uses ServerTextControl, described in Using ServerTextControl in Desktop Applications.

Port the Code

Start with a Windows Forms project that has a TextControl on its form, as Create Your First Windows Forms Application creates it. Then rewrite each ActiveX call with the tables below. This handler in Form1.cs shows the three most common changes, with the ActiveX code in the comments:

using TXTextControl;

private void PortedCode()
{
    // ActiveX: TXTextControl1.FontBold = True
    textControl1.Selection.Bold = true;

    // ActiveX: TXTextControl1.IndentL = 567
    textControl1.Selection.ParagraphFormat.LeftIndent = 567;

    // ActiveX: FieldNext, FieldCurrent and FieldText in a loop
    foreach (TextField field in textControl1.TextFields)
    {
        System.Diagnostics.Debug.WriteLine(field.Text);
    }
}

The code works as follows:

• Selection.Bold sets the bold attribute of the selected text, the way FontBold did.
• Selection.ParagraphFormat returns the ParagraphFormat of the selected paragraphs. LeftIndent is given in twips, like IndentL.
• TextFields returns the TextFieldCollection of the document. The foreach loop visits every TextField, and Text is a property of the field itself.

The pages of the Document Editor section explain each area of the .NET interface in detail, such as Text and Paragraph Formatting, Tables and Table Formulas and Fields, Hyperlinks, and Bookmarks.

Map the Members by Category

Each table lists the members of the ActiveX control TXTextControl in one category, linked to the ActiveX reference, and the .NET classes, properties, methods or events that replace them. Members with no .NET counterpart are listed in Members Without a Counterpart.

Character Formatting

Paragraph Formatting

Bullets and Numbered Lists

Headers and Footers

Text Frames

Page and Document Settings

Stylesheets

Tables

Zooming

Loading, Saving and Database Support

Images and OLE Objects

Hypertext Links

Clipboard Operations

Undo

Printing

Search and Replace

Columns

Sections

Control Styles and Mode Settings

Line Operations

Text Controls Without a Built-In Scroll Interface

Selections and Character Input

Marked Text Fields

Integrated Dialog Boxes

Handling XML Documents

Tool Bar Support

Restricted Document Access

Miscellaneous

Port the Tool Bars

The ActiveX tool bars TXButtonBar, TXRulerBar and TXStatusBar have the .NET counterparts ButtonBar, RulerBar and StatusBar. An ActiveX application connected them through window handles such as ButtonBarHandle. In .NET, you assign the bar object to the properties ButtonBar, RulerBar, VerticalRulerBar and StatusBar of the TextControl, in the Properties window or in code, and the ConnectTools event is no longer needed.

Add Rulers, Toolbars, and a Status Bar builds this layout step by step. Instead of the button bar, a Windows Forms application can also use the ribbon, described in Built-in Ribbon Tabs.

The members of the three bars map as follows.

Button Bar

Ruler Bar

Status Bar

Members Without a Counterpart

No Longer Needed

These ActiveX members have no .NET counterpart because the .NET interface solves their task another way:

Not Available in .NET

These ActiveX members have no replacement in TX Text Control .NET for Windows Forms:

• Page and Document Settings: Device
• Loading, Saving and Database Support: DataTextFormat
• Images and OLE Objects: ImageDisplayMode, ObjectGetData, ObjectGethWnd, ObjectGetZoom, ObjectItem, ObjectPrint, ObjectScrollOut, ObjectSetData, ObjectSetZoom
• Printing: PrintOffset, PrintZoom
• Control Styles and Mode Settings: ClipChildren, ClipSiblings, WordWrapMode
• Text Controls Without a Built-In Scroll Interface: AutoScroll, CaretOut, CaretOutBottom, CaretOutLeft, CaretOutRight, CaretOutTop, Move, Size, SizeMode
• Selections and Character Input: KeyStateChange
• Chains of Linked Text Controls: AutoLink, NextWindow
• Miscellaneous: GetTextExtent

Next Steps

• Create Your First Windows Forms Application: the project the ported code goes into.
• Add Rulers, Toolbars, and a Status Bar: the .NET button bar, rulers and status bar around the editor.
• Migrating from .NET Framework to .NET: move a ported .NET Framework project on to .NET 8 or higher.
• TX Text Control ActiveX: the documentation of the ActiveX control and its members.