下面是一个完整的code样品（使用丰富的code-后面）。

MainWindow.xaml：

 ＆LT;窗​​口x：类=主窗口
        的xmlns =htt​​p://schemas.microsoft.com/winfx/2006/xaml/$p$psentation
        的xmlns：X =htt​​p://schemas.microsoft.com/winfx/2006/xaml
        标题=主窗口高度=350宽度=525＆GT;
    ＆LT; StackPanel的保证金=12＆GT;
        ＆LT; TabControl的名称=tabControl1高度=250/＆GT;
        ＆LT;按钮内容=添加矩形点击=Button_Click
                WIDTH =90高度=25保证金=5/＆GT;
    ＆LT; / StackPanel的＆GT;
＆LT; /窗＆GT;
 

MainWindow.xaml.cs：

 使用系统;
使用System.Collections.Generic;
使用System.Linq的;
使用System.Windows;
使用System.Windows.Controls的;
使用System.Windows.Media;
使用System.Windows.Shapes;

公共类地板
{
    公用建筑（字符串名称= NULL）
    {
        this.Name =名称;
    }

    公共字符串名称{;组; }
}

公共类FakeDb
{
    公开的IEnumerable＆LT;地板＆GT;地板
    {
        得到
        {
            返回新的List＆LT;地板＆GT;（）
            {
                新楼（floor1），
                新楼（floor2），
                新楼（层3），
            };
        }
    }
}

公共部分类主窗口：窗口
{
    公共主窗口（）
    {
        的InitializeComponent（）;
        InitializeTabControl（）;
    }

    私人无效InitializeTabControl（）
    {
        变种DB =新FakeDb（）;
        VAR floorNames =（从FN在db.Floors选择fn.Name）.ToList（）;

        的foreach（在floorNames串floorName）
        {
            VAR项目=新的TabItem（）
            {
                标题= floorName，
                内容=新的网格（）
            };
            tabControl1.Items.Add（项目）;
        }
    }

    私人无效Button_Click（对象发件人，RoutedEventArgs E）
    {
        VAR随机=新的随机（）;
        VAR矩形=新的Rectangle（）
        {
            行程= Brushes.Black，
            填写= Brushes.SkyBlue，
            宽度= 50，
            身高= 75，
            保证金=新的厚度（
                左：random.NextDouble（）* 300，
                顶：random.NextDouble（）* 150，
                右：0，
                底部：0）
            的Horizo​​ntalAlignment = Horizo​​ntalAlignment.Left，
            VerticalAlignment = VerticalAlignment.Top，
        };
        VAR电网=（网格）tabControl1.SelectedContent;
        grid.Children.Add（矩形）;
    }
}
 

The number of tab items are not predetermined. I just want to create new tab items and then add new rectangles inside current items. I am generating new tab items(bellow is code) but how can I add rectangles in current tab?

var _FloorName = (from fn in db.floors select fn.floorname).ToList();

if (_FloorName.Count > 0)
{
    for (int i = 0; i < _FloorName.Count; i++)
    {
        tabControl1.Items.Add(_FloorName[i]);
    }
}

Here is one approach you could take:

Here is a complete code sample (using copious code-behind).

MainWindow.xaml:

<Window x:Class="MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="MainWindow" Height="350" Width="525">
    <StackPanel Margin="12">
        <TabControl Name="tabControl1" Height="250" />
        <Button Content="Add Rectangle" Click="Button_Click"
                Width="90" Height="25" Margin="5" />
    </StackPanel>
</Window>

MainWindow.xaml.cs:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Shapes;

public class Floor
{
    public Floor(string name = null)
    {
        this.Name = name;
    }

    public string Name { get; set; }
}

public class FakeDb
{
    public IEnumerable<Floor> Floors
    {
        get
        {
            return new List<Floor>()
            {
                new Floor("floor1"),
                new Floor("floor2"),
                new Floor("floor3"),
            };
        }
    }
}

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
        InitializeTabControl();
    }

    private void InitializeTabControl()
    {
        var db = new FakeDb();
        var floorNames = (from fn in db.Floors select fn.Name).ToList();

        foreach (string floorName in floorNames)
        {
            var item = new TabItem()
            {
                Header = floorName,
                Content = new Grid(),
            };
            tabControl1.Items.Add(item);
        }
    }

    private void Button_Click(object sender, RoutedEventArgs e)
    {
        var random = new Random();
        var rectangle = new Rectangle()
        {
            Stroke = Brushes.Black,
            Fill = Brushes.SkyBlue,
            Width = 50,
            Height = 75,
            Margin = new Thickness(
                left: random.NextDouble() * 300,
                top: random.NextDouble() * 150,
                right: 0,
                bottom: 0),
            HorizontalAlignment = HorizontalAlignment.Left,
            VerticalAlignment = VerticalAlignment.Top,
        };
        var grid = (Grid)tabControl1.SelectedContent;
        grid.Children.Add(rectangle);
    }
}