Binding text property of text box to variable defined on MainWindow-WPF - wpf

Question

I'm newbie on WPF and I have text box and button which open folder browser dialog.
When the user select folder I would like text box will contain the selected path.
So on MainWindow I added two variables:
public partial class MainWindow : Window
{
public string outputFolderPath { get; set; }
string reducedModelFolderPath { get; set; }
}
and when user selected folder path (after open folder dialog) I updated those variables by doing (for example):
outputFolderPath = dialog.SelectedPath
In MainWindow.xaml:
<TextBox x:Name="outputFolder" Width ="200" Height="30" Grid.Row="1" Grid.Column="1" Margin="5 10">
How can I bind TextBox.Text to outputFolderPath variable?
Thanks for your assitance!

Answer 1

You need to set DataContext of your window to this, to access your property in XAML, and after that bind to the property. As you are binding not to DependencyProperty, you should notify your binding that property has changed, which could be done by implementing INotifyPropertyChanged interface in your Window.
I've provided sample code to show the concept.
But this is very ugly, much better to use MVVM pattern instead.
MainWindow.xaml.cs
public partial class MainWindow : Window, INotifyPropertyChanged
{
public string outputFolderPath { get; set; }
public MainWindow()
{
InitializeComponent();
DataContext = this;
}
public event PropertyChangedEventHandler PropertyChanged;
private void Button_Click(object sender, RoutedEventArgs e)
{
outputFolderPath = "Some data";
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(nameof(outputFolderPath)));
}
}
MainWindow.xaml
<Window x:Class="simplest.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:simplest"
mc:Ignorable="d"
Title="MainWindow" Height="350" Width="525">
<Grid>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition />
<RowDefinition />
</Grid.RowDefinitions>
<Button Click="Button_Click" Content="Go" />
<TextBox x:Name="outputFolder" Width ="200" Height="30" Grid.Row="1" Grid.Column="1" Margin="5 10" Text="{Binding outputFolderPath}"/>
</Grid>
</Window>