我是WPF的新手，还在学习数据绑定。
我正在从文件中阅读数据并使用文件数据填充模型。我想这个数据显示在文本框中的程序启动时。但是，程序启动时不会填充数据，文本框为空。为这两个属性调用sets和gets，并且值是正确的，但文本框为空。
有人能给我指个方向吗？我错过了什么？
下面是我的App.xaml：

public partial class App : Application
    {
        protected override void OnStartup(StartupEventArgs e)
        {
            base.OnStartup(e);
            MainWindow window = new MainWindow();
            MainWindowViewModel mainWindow = new MainWindowViewModel(GetConfigFile());
            window.DataContext = mainWindow;
        }

        static string GetConfigFile()
        {
            string config = string.Empty;
            string assem = System.Reflection.Assembly.GetExecutingAssembly().Location;
            string path = Path.GetDirectoryName(assem);
            string[] files = Directory.GetFiles(path, "*.xml");
            foreach (string file in files)
            {
                if (file.ToLower().Contains("matrx") || file.ToLower().Contains("matrix"))
                {
                    config = file;
                    break;
                }
            }
            return config;
        }
    }

MainWindowViewModel.cs:

public class MainWindowViewModel : ViewModelBase
    {
        public Configuration Config { get; set; }

        public MainWindowViewModel(string configFile) 
        {
            base.DisplayName = Resources.MainWindowViewModel_DisplayName;
            Config = new Configuration(configFile);

        }
    }

Configuration.cs:

public class Configuration : INotifyPropertyChanged
    {
        public event PropertyChangedEventHandler PropertyChanged;

        string _thisIp;
        public string ThisIp
        { 
            get { return _thisIp; } 
            set 
            { 
                _thisIp = value;
                OnPropertyChanged("ThisIp");
            } 
        }

        string _thisPort;
        public string ThisPort
        { 
            get { return _thisPort; } 
            set 
            { 
                _thisPort = value;
                OnPropertyChanged("ThisPort");
            } 
        }

        public Configuration(string configPath)
        {
            LoadConfig(configPath);
        }

        void LoadConfig(string path)
        {
            if (!String.IsNullOrEmpty(path))
            {
                XElement config;
                using (XmlReader reader = XmlReader.Create(path))
                {
                    config = XElement.Load(reader);
                }
                foreach (XElement node in config.Elements())
                {
                    if (node.Name.ToString().Equals("Device"))
                    {
                        foreach (XElement innerNode in node.Elements())
                        {
                            string name = innerNode.Name.ToString().ToLower();
                            if (name.Equals("ipaddr"))
                            {
                                ThisIp = innerNode.Value;
                            }
                            else if (name.Equals("port"))
                            {
                                ThisPort = innerNode.Value;
                            }
                        }
                        break;
                    }
                }
            }
            else
            {
                // Load defaults
                ThisPort = "7111";
            }
        }

        protected virtual void OnPropertyChanged(string propertyName)
        {
            if (this.PropertyChanged != null)
            {
                this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
            }
        }
    }

MainWindow.xaml代码段：

<Grid x:Name="Grid_DeviceIP" HorizontalAlignment="Left" VerticalAlignment="Top" Width="450">
    <Grid.Resources >
        <Style TargetType="Border" >
            <Setter Property="Padding" Value="5,5,5,5" />
        </Style>
    </Grid.Resources>
    <Grid.ColumnDefinitions>
        <ColumnDefinition Width="2*" />
        <ColumnDefinition Width="4*" />
    </Grid.ColumnDefinitions>
    <Grid.RowDefinitions>
        <RowDefinition Height="*" />
        <RowDefinition Height="*" />
    </Grid.RowDefinitions>
    <Label Grid.Row="0" FontWeight="Bold" FontSize="14">Configuration</Label>
    <Border Grid.Row="1" Grid.Column="0">
        <Label HorizontalAlignment="Right">This IP</Label>
    </Border>
        <Border Grid.Row="1" Grid.Column="1">
            <TextBox x:Name="TextBox_ThisIP" Width="275" Text="{Binding Config.ThisIp, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"></TextBox>
        </Border>
    <Border Grid.Row="2" Grid.Column="0">
        <Label HorizontalAlignment="Right">This Port</Label>
    </Border>
    <Border Grid.Row="2" Grid.Column="1">
        <TextBox x:Name="TextBox_ThisPort" Width="275" Text="{Binding Config.ThisPort, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"></TextBox>
    </Border>
</Grid>

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