Visão geral sobre TextBox

The TextBox class enables you to display or edit unformatted text. A common use of a TextBox is editing unformatted text in a form. For example, a form asking for the user's name, phone number, etc would use TextBox controls for text input. This topic introduces the TextBox class and provides examples of how to use it in both Extensible Application Markup Language (XAML) and C#.

Este tópico contém as seguintes seções.

• TextBox or RichTextBox?
• Creating TextBoxes
• Detect When Content Changes
• Tópicos relacionados

TextBox or RichTextBox?

Both TextBox and RichTextBox allow users to input text but the two controls are used for different scenarios. A TextBox requires less system resources then a RichTextBox so it is ideal when only plain text needs to be edited (i.e., usage in a form). A RichTextBox is a better choice when it is necessary for the user to edit formatted text, images, tables, or other supported content. For example, editing a document, article, or blog that requires formatting, images, etc is best accomplished using a RichTextBox. The table below summarizes the primary features of TextBox and TextBox.

Control	Real-time Spellchecking	Context Menu	Formatação de comandos como ToggleBold (ctr + B)	FlowDocument content like images, paragraphs, tables, etc.
TextBox	Yes	Yes	No	No.
RichTextBox	Yes	Yes	Yes (see Visão geral de RichTextBox)	Yes (see Visão geral de RichTextBox)

Observação

Embora TextBox não oferece suporte a comandos de edição relacionados formatação como ToggleBold (Ctr + B), muitos comandos básicos são suportados por ambos os controles, como MoveToLineEnd.See EditingCommands for more information.

Features supported by TextBox are covered in the sections below. For more information about RichTextBox, see Visão geral de RichTextBox.

Real-time Spellchecking

You can enable real-time spellchecking in a TextBox or RichTextBox. When spellchecking is turned on, a red line appears underneath any misspelled words (see picture below).

See Como: Enable Spell Checking in a Text Editing Control to learn how to enable spellchecking.

Context Menu

By default, both TextBox and RichTextBox have a context menu that appears when a user right-clicks inside the control. The context menu allows the user to cut, copy, or paste (see picture below).

You can create your own custom context menu to override the default behavior. See Como: Use a Custom Context Menu with a TextBox for more information.

Creating TextBoxes

A TextBox can be a single line in height or comprise multiple lines. Uma única linha TextBox é melhor para a inserção de pequenas quantidades de texto sem formatação (por exemplo, " O nome","Telefone", etc. em um formulário). The following example shows how to create a single line TextBox.

<Page  xmlns="https://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="https://schemas.microsoft.com/winfx/2006/xaml">
  <StackPanel>
    <TextBox Width="200" MaxLength="100" />
  </StackPanel>
</Page>

You can also create a TextBox that allows the user to enter multiple lines of text. For example, if your form asked for a biographical sketch of the user, you would want to use a TextBox that supports multiple lines of text. The following example shows how to use Extensible Application Markup Language (XAML) to define a TextBox control that automatically expands to accommodate multiple lines of text.

<TextBox
  Name="tbMultiLine"
  TextWrapping="Wrap"
  AcceptsReturn="True"
  VerticalScrollBarVisibility="Visible"
>
  This TextBox will allow the user to enter multiple lines of text.  When the RETURN key is pressed, 
  or when typed text reaches the edge of the text box, a new line is automatically inserted.
</TextBox>

Setting the TextWrapping attribute to Wrap causes text to wrap to a new line when the edge of the TextBox control is reached, automatically expanding the TextBox control to include room for a new line, if necessary.

Setting the AcceptsReturn attribute to true causes a new line to be inserted when the RETURN key is pressed, once again automatically expanding the TextBox to include room for a new line, if necessary.

The VerticalScrollBarVisibility attribute adds a scroll bar to the TextBox, so that the contents of the TextBox can be scrolled through if the TextBox expands beyond the size of the frame or window that encloses it.

For more information on different tasks associated with using a TextBox, see Tópicos de Como Fazer para TextBox.

Detect When Content Changes

Usually the TextChanged event should be used to detect whenever the text in a TextBox or RichTextBox changes, rather then KeyDown as you might expect. See Como: Detectar quando o texto em uma TextBox foi alterado for an example.

Consulte também

Conceitos

Visão geral de RichTextBox

Outros recursos

Tópicos de Como Fazer para TextBox