WPF

<FontFamily x:Key="Font.Family.Default">Segoe UI</FontFamily>
<sys:Double x:Key="Font.Size.Header1">18</sys:Double>
<sys:Double x:Key="Font.Size.Header2">16</sys:Double>
<sys:Double x:Key="Font.Size.Header3">14</sys:Double>
<sys:Double x:Key="Font.Size.Normal">12</sys:Double>

<SolidColorBrush x:Key="TextBlock.Static.Background" Color="Transparent"/>
<SolidColorBrush x:Key="TextBlock.Static.Foreground" Color="DarkGray"/>

<Style x:Key="ControlBase" TargetType="{x:Type Control}">

    <Setter Property="Control.FontSize" Value="{StaticResource Font.Size.Normal}"/>
    <Setter Property="Control.FontFamily" Value="{StaticResource Font.Family.Default}"/>
    <Setter Property="Control.HorizontalAlignment" Value="Center"/>
    <Setter Property="Control.VerticalAlignment" Value="Center"/>

</Style>

<Style TargetType="{x:Type TextBlock}"
        BasedOn="{StaticResource ControlBase}">

    <Setter Property="Background" Value="{StaticResource TextBlock.Static.Background}"/>
    <Setter Property="Foreground" Value="{StaticResource TextBlock.Static.Foreground}"/>

</Style>

<TextBlock Grid.Row="0" 
            Grid.Column="0"
            Text="Test"
            Margin="22,0,0,0"/>

System.Windows.Markup.XamlParseException
  Message='Initialization of 'System.Windows.Controls.TextBlock' threw an exception.' Line number '56' and line position '20'.

    Inner Exception 1:
    InvalidOperationException: Can only base on a Style with target type that is base type 'TextBlock'.

<Style TargetType="TextBlock">

    <Setter Property="Foreground" Value="{DynamicResource textForegroundBrush}"/>
    <Setter Property="FontSize" Value="14"/>

</Style>

<Window.Resources>

    <Style x:Key="headerTextStyle" 
            TargetType="TextBox">

        <Setter Property="FontSize" Value="24"/>

    </Style>

</Window.Resources>

using ...

namespace Gewicht
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public string[] dbFile = { @"H:\Daten\C#WPF\Gewicht\GewichtDaten.xml", @"H:\Daten\C#WPF\Gewicht\GewichtDaten.xsd" };
        public DataTable dbDataTbl = new DataTable();

        public MainWindow()
        {
            InitializeComponent();
        }

        private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            if (!System.IO.File.Exists(dbFile[0]) | !System.IO.File.Exists(dbFile[1]))
                {
                SystemSounds.Beep.Play();
                MessageBox.Show("Die Datei" + Environment.NewLine + "   " + dbFile[0] + Environment.NewLine + "und/oder" + Environment.NewLine + "   " + dbFile[1] + Environment.NewLine + "fehlt." + Environment.NewLine + "Das Programm wird beendet.", "Fehler", MessageBoxButton.OK, MessageBoxImage.Error);
                Environment.Exit(0);
            }
            DataGrid1.CanUserAddRows = false;
            DataGrid1.CanUserDeleteRows = false;
            OpenData();
        }


        private void DataGrid1_CellEditEnding(object sender, DataGridCellEditEndingEventArgs e)
        {
            // edit
            // ... ???????????????????????? ...
        }


        private void OpenData()
        {
            // open data

            dbDataTbl.Columns.Clear();
            dbDataTbl.Rows.Clear();
            dbDataTbl = new DataTable("ich");
            dbDataTbl.ReadXmlSchema(dbFile[1]);
            dbDataTbl.ReadXml(dbFile[0]);
            // DataGrid
            DataSet dataSet = new DataSet();
            dataSet.ReadXml(dbFile[0]);
            DataView dataView = new DataView(dataSet.Tables[0]);
            DataGrid1.ItemsSource = dataView;
            // format columns
            Style style = new Style();               // creates object of style class   
            style.TargetType = typeof(DataGridCell); // sets target type as DataGrid cell
            Setter setter = new Setter();            // create objects of setter class   
            setter.Property = DataGridCell.ForegroundProperty;
            setter.Value = Brushes.LightGray;
            style.Setters.Add(setter);
            DataGrid1.Columns[0].CellStyle = style;
            style = new Style();
            setter = new Setter();
            setter.Property = DataGridCell.HorizontalContentAlignmentProperty;
            setter.Value = HorizontalAlignment.Right;
            DataGrid1.Columns[2].CellStyle = style;
        }

    }
}

<DrawingImage x:Key="FindIcon"/>
<DrawingImage x:Key="SearchIcon"/>

<Image Source="{StaticResource FindIcon}"/>
<Image Source="{StaticResource SearchIcon}"/>

<Image Source="{Binding ChooseIcon}"/>

public DrawingImage ChooseIcon
{
    get
    {
        if (useFindIcon)
        {
            return ???; // how to reference the static resource "FindIcon"
        }
        else if (useSearchIcon)
        {
            return ???;// how to reference the static resource "SearchIcon"
        }
    }
}

Jobs
    Ship To Address

Builders

Foremen
    Foreman Phone

Vendors
Vendor Locations
Vendor Contacts
    Vendor Contact Email
    Vendor Contact Phone

Delivery Method (Will Call or Delivery)
Delivery Date 
For Will Call
    Picked Up By (employee)
    Picked Up By Email
    Picked Up By Email
    Picked Up Location (From Vendor Locations)

Items (The items on the PO)