WPF TextBox in VB.NET

WPF TextBox Control

This article demonstrates how to create and use a TextBox control in WPF using XAML and VB.NET.

Creating a TextBox

The TextBox element represents a WPF TextBox control in XAML.

<TextBox/>

The Width and Height attributes of the TextBox element represent the width and the height of a TextBox. The Text property of the TextBox element sets the content of a TextBox. The x:Name attribute represents the name of the control, which is a unique identifier of a control.

The code snippet in Listing 1 creates a TextBox control and sets the name, height, width, and content of a TextBox control.

<TextBox x:Name="TextBox1" Height="30" Width="200"
        Text="Hello! This is TextBox Eample.">
</TextBox>

Listing 1

The output looks like Figure 1.



Figure 1

As you can see from Figure 1, by default the TextBox is place in the center of the page. We can place a TextBox control where we want by using the Margin, VerticalAlignment and HorizontalAlignment attributes that sets the margin, vertical alignment, and horizontal alignment of a control.

The code snippet in Listing 2 sets the position of the TextBox control in the left top corner of the page.

<TextBox x:Name="TextBox1" Height="30" Width="200"
        Text="Hello! This is TextBox Eample."
        Margin="10,10,0,0" VerticalAlignment="Top"
        HorizontalAlignment="Left">
</TextBox>

Listing 2

Formatting a TextBox

The BorderBrush property of the TextBox sets a brush to draw the border of a TextBox. You may use any brush to fill the border. The code snippet in Listing 3 uses a linear gradient brush to draw the border with a combination of red and blue color.

<TextBox x:Name="TextBox1" Height="30" Width="200"
        Text="Hello! This is TextBox Eample."
        Margin="10,10,0,0" VerticalAlignment="Top"
        HorizontalAlignment="Left">
            <TextBox.BorderBrush>
                <LinearGradientBrush StartPoint="0,0" EndPoint="1,1" >
                    <GradientStop Color="Green" Offset="0" />
                    <GradientStop Color="Yellow" Offset="1.0" />
                </LinearGradientBrush>
            </TextBox.BorderBrush>
 </TextBox>

The output looks like Figure 2



Figure 2

Listing 3

The Background and Foreground properties of the TextBox set the background and foreground colors of a TextBox. You may use any brush to fill the border. The following code snippet uses linear gradient brushes to draw the background and foreground of a TextBox.

<TextBox x:Name="TextBox1" Height="30" Width="200"
        Text="Hello! This is TextBox Eample."
        Margin="10,10,0,0" VerticalAlignment="Top"
        HorizontalAlignment="Left">
            <TextBox.BorderBrush>
                <LinearGradientBrush StartPoint="0,0" EndPoint="1,1" >
                    <GradientStop Color="Green" Offset="0" />
                    <GradientStop Color="Yellow" Offset="1.0" />
                </LinearGradientBrush>
            </TextBox.BorderBrush>
            <TextBox.Background>
                <LinearGradientBrush StartPoint="0,0" EndPoint="1,1" >
                    <GradientStop Color="RosyBrown" Offset="0.1" />
                    <GradientStop Color="RoyalBlue" Offset="0.25" />
                    <GradientStop Color="Bisque" Offset="0.75" />
                    <GradientStop Color="MediumOrchid" Offset="1.0" />
                </LinearGradientBrush>
            </TextBox.Background>
            <TextBox.Foreground>
                <LinearGradientBrush StartPoint="0,0" EndPoint="1,1" >
                    <GradientStop Color="Orange" Offset="0.25" />
                    <GradientStop Color="Black" Offset="1.0" />
                </LinearGradientBrush>
            </TextBox.Foreground>
        </TextBox>

The new TextBox looks like Figure 3.



Figure 3

Setting Image as Background of a TextBox

To set an image as background of a TextBox, we can set an image as the Background of the TextBox. The code snippet in Listing 4 sets the background of a TextBox to an image.

<TextBox.Background>
                <ImageBrush ImageSource="Correct4.JPG" />
 </TextBox.Background>

Listing 4

The new output looks like Figure 4.



Figure 4

Creating a TextBox Dynamically

The code listed in Listing 5 creates a TextBox control programmatically. First, it creates a TextBox object and sets its width, height, contents, background and foreground and later the TextBox is added to the LayoutRoot.

   Private Sub CreateATextBox()
        Dim txtb As TextBox = New TextBox()
        txtb.Height = 50
        txtb.Width = 200
        txtb.Text = "Text Box content"
        txtb.Background = New SolidColorBrush(Colors.Orange)
        txtb.Foreground = New SolidColorBrush(Colors.Black)
        LayoutRoot.Children.Add(txtb)
    End Sub

Listing 5

Setting Fonts of TextBox Contents

The FontSize, FontFamily, FontWeight, FontStyle, and FontStretch properties are used to set the font size, family, weight, style and stretch to the text of a TextBox. The code snippet in Listing 6 sets the font properties of a TextBox.

FontSize="14" FontFamily="Verdana" FontWeight="Bold"

Listing 6

The new output looks like Figure 5.



Figure 5

The FontSource property allows loading custom fonts dynamically. The following code snippet sets the FontSource property.

       Dim fontUri As Uri = New Uri("SomeFont.ttf", UriKind.Relative)
       Dim MySRI As StreamResourceInfo = Application.GetResourceStream(fontUri)
       TextBox1.FontSource = New FontSource(MySRI.Stream)

Non Editable TextBox

The IsReadOnly property of the TextBox sets the text box read only. By default, it is false.

IsReadOnly="True"

Restricting Text Size of a TextBox

The MaxLength property of the TextBox sets the number of characters allowed to input in a text box.

MaxLength="250"

Scrolling, Alignment, and Wrapping

The HorizontalScrollBarVisibility and VerticalScrollBarVisibility properties are used to set horizontal and vertical scroll bars of a TextBox, which is of type ScrollBarVisibility enumeration. The ScrollBarVisibility enumeration has four values are Disabled, Auto, Hidden, and Visible. The following code snippet sets the horizontal and vertical scroll bars visible in a TextBox.

HorizontalScrollBarVisibility="Visible"
VerticalScrollBarVisibility="Auto"

The TextWrapping property sets the wrap of no warp text. The following code snippet sets the wrapping text option.

TextWrapping="Wrap"

The TextAlignment property sets the text alignment in a TextBox, which is of type TextAlignment enumeration. A text can be aligned left, center, or right.

TextAlignment="Right"

The AcceptReturn property sets if the return is accepted in a TextBox or not.

AcceptsReturn="True"

Listing 7 shows all these properties in a complete sample.

<TextBox x:Name="TextBox2" Margin="10,10,50,0"
         Width="300" Height="150"
         HorizontalScrollBarVisibility="Visible"
         VerticalScrollBarVisibility="Visible"
         TextWrapping="Wrap"
         TextAlignment="Right"
         MaxLength="500"
         IsReadOnly="False"
         AcceptsReturn="True" >           
</TextBox>

Listing 7

Selection in TextBox

The Select and SelectAll methods are used to select text in a TextBox. The Select method select a text range in a TextBox and the SelectAll method select all text in a TextBox.

The SelectionBackground and SelectionForeground properties set the background and foreground colors of the selected text. The SelectedText property returns the selected text in a TextBox.

The code in Listing 8 sets the selected text background and foreground properties and on button click event handler, returns the selected text of the TextBox.

   Private Sub TextBox2Functionality()
        Dim textBoxData As String = "Hey I am a text with scrolling and return functionality."
        textBoxData += " You can select text it me and get the selected data. "
        textBoxData += " How about setting background and foreground color of the selected text?. "
        textBoxData += " Maximum lenght and a lot more to offer. "
        textBoxData += " You can select text it me and get the selected data. "
        textBoxData += " You can select text it me and get the selected data. "
        textBoxData += " Also sets the selection background and foreground "
        textBoxData += " Set font size and the font name. "
        textBoxData += " You can select text it me and get the selected data. "
        textBoxData += " Also sets the selection background and foreground "
        textBoxData += " Set font size and the font name. "
        textBoxData += " You can select text it me and get the selected data. "
        TextBox2.Text = textBoxData
        TextBox2.FontFamily = New FontFamily("Georgia")
        TextBox2.FontSize = 12
        TextBox2.SelectionBackground = New SolidColorBrush(Colors.Blue)
        TextBox2.SelectionForeground = New SolidColorBrush(Colors.White)
        TextBox2.SelectionStart = 100
        TextBox2.SelectionLength = 200
    End Sub
   Private Sub Button_Click(ByVal sender As Object, ByVal e As RoutedEventArgs)
        MessageBox.Show(TextBox2.SelectedText)
    End Sub

Listing 8

The new output looks like Figure 6.



Figure 6

Summary

In this article, I discussed how we can create and format a TextBox control in WPF and VB.NET. After that we saw how to create a TextBox control dynamically. Then we saw how to set various properties of a TextBox such as making it non editable, restrict the size of text, and set the foreground an d background of the selected text.