Button Control in WPF

Dinesh Beniwal
Feb 02, 2009
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Creating a Button

The Button element represents a WPF Button control in XAML.

The Width and Height attributes of the Button element represent the width and the height of a Button. The Content property of the Button element sets the text of a button. 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 Button control and sets the name, height, width, and content of a Button control.

Button x:Name="DrawCircleButton" Height="80" Width="150"

Content="Draw Circle" >

</Button>

Listing 1

Figure 1

As you can see from Figure 1, by default the Button is place in the center of the page. We can place a Button 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 Button control in the left top corner of the page.

<Button x:Name="DrawCircleButton" Height="30" Width="100"

Content="Draw Circle"

Margin="10,10,0,0" VerticalAlignment="Top"

HorizontalAlignment="Left">

</Button>

Listing 2

Figure 2

Adding a Button Click Event Handler

The Click attribute of the Button element adds the click event handler. The following code adds the click event handler for a Button.

</Button>

The code for the click event handler looks like following.

private void RandomNumber_Click(object sender, RoutedEventArgs e)

{

}

Now, whatever code you write in the click event handler that will be executed on the Button click. The code listed in Listing 3 creates a random number the Button click event handler.

        public void RandomNumber_Click(object sender, EventArgs e)
        {
            Random generator = new Random();
            int randomValue;
            randomValue = generator.Next(1, 10);
            textBlock1.Text += " " + randomValue.ToString();
        }

Listing 3

The Code of the Windows.xaml :

<Window x:Class="HelloWPF.Window1"
   xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
   xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
   Title="Window1" Height="300" Width="300">
    <Grid Background="Azure">
        <Button Height="23" Margin="15,15,125,0" Name="RandomNumber" VerticalAlignment="Top" Click="RandomNumber_Click" Background="Blue">Random Number

        </Button>
        <ScrollViewer Margin="0,50,0,0">
            <TextBlock Name="textBlock1" TextWrapping="Wrap" FontSize="20" FontWeight="Bold" />
        </ScrollViewer>
    </Grid>
</Window>

The Code of the Windows.xaml.cs:

   public void RandomNumber_Click(object sender, EventArgs e)
        {
             Random generator = new Random();
             int randomValue;
             randomValue = generator.Next(1, 10);
             textBlock1.Text += " " + randomValue.ToString();
         }

The Output is :

Figure 3

Formatting a Button

Not let's get a little creative. How about we create a Button control with a border formatting, background, and foreground of the Button?

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

<Button.BorderBrush>

</LinearGradientBrush>

</Button.BorderBrush>

The Background and Foreground properties of the Button set the background and foreground colors of a Button. 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 Button.

<Button.Background>