Different updates in two way binding

Hello @BitSmithy ,

Welcome to Microsoft Q&A!

It is recommended that you use element binding Text="{Binding ElementName=rectangleTest, Path=Width}", and change the Rectangle.WidthProperty in event TextChanged.

<StackPanel>
    <Rectangle x:Name="rectangleTest" Height="200" Width="100" Fill="Red"/>
    <TextBox x:Name="textboxTest" Text="{Binding ElementName=rectangleTest, Path=Width}" TextChanged="textboxTest_TextChanged" Height="50" Width="100"/>
    <Button Content="change the width" Click="Button_Click" />
</StackPanel>

private void textboxTest_TextChanged(object sender, TextChangedEventArgs e)
{
    double dbWidth;

    if (double.TryParse(textboxTest.Text, out dbWidth))
    {
        if (dbWidth >= 0)
        {
            rectangleTest.Width = dbWidth;
        }
    }
}

private void Button_Click(object sender, RoutedEventArgs e)
{
    rectangleTest.Width = 300;
}

Thank you.

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