FileFolderOpenDialogs.XAML

<Window
    x:Class="OpenFileOrFolder.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:local="clr-namespace:OpenFileOrFolder"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    Title="MainWindow"
    Width="300"
    Height="150"
    mc:Ignorable="d">
    <Grid>
        <StackPanel>
            <TextBox x:Name="filePath" />
            <Button
                x:Name="selectFileBtn"
                Click="selectFileBtn_Click"
                Content="Win 32 Style File Dialog" />

            <TextBox x:Name="winFormsFilePath" />
            <Button
                x:Name="winFormsFilePathBtn"
                Click="selectWinFormsFileBtn_Click"
                Content="Win Forms Style File Dialog" />

            <TextBox x:Name="folderPath" />
            <Button
                x:Name="selectFolderBtn"
                Click="selectFolderBtn_Click"
                Content="Select Folder" />
        </StackPanel>

    </Grid>
</Window>