5. Events

Events tell the application when something happens.

Examples include:

• Button clicked
• Mouse moved
• Key pressed
• Window loaded

---

Click Event #

<Button
    Content="Save"
    Click="SaveButton_Click"/>

When the button is clicked, WPF automatically calls:

private void SaveButton_Click(object sender, RoutedEventArgs e)
{
    MessageBox.Show("Saved!");
}

---

Window Loaded Event #

<Window
    Loaded="Window_Loaded">

C#:

private void Window_Loaded(object sender, RoutedEventArgs e)
{
    MessageBox.Show("Application Started");
}

---

TextChanged Event #

<TextBox
    TextChanged="TextBox_TextChanged"/>

This event occurs whenever the text changes.

---

Complete Example #

<Window
    x:Class="Demo.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Employee Form"
    Width="450"
    Height="250"
    WindowStartupLocation="CenterScreen">

    <Grid Margin="20">

        <StackPanel>

            <TextBlock
                Text="Employee Name"
                Margin="0,0,0,5"/>

            <TextBox
                x:Name="txtName"
                Margin="0,0,0,10"/>

            <Button
                Content="Save"
                Width="100"
                Height="35"
                Click="Save_Click"/>

        </StackPanel>

    </Grid>

</Window>

Code Behind:

private void Save_Click(object sender, RoutedEventArgs e)
{
    MessageBox.Show($"Hello {txtName.Text}");
}