Question

WPF新手。

我正在尝试将我的模型绑定到我的UI。因此，在我的用户操作期间更改属性时，我希望该字段在我的UI上发生更新。

这是我的模特：

namespace WpfApplication1
{
    public class model2
    {
        private static string myField2;

        public static string MyField2
        {

            get { return myField2; }
            set { myField2 = value; }
        }
    }
}

我的标记：

<Window x:Class="WpfApplication1.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:WpfApplication1"       
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <local:model2 x:Key="mymodel"/>
    </Window.Resources>
    <Grid>
        <StackPanel Orientation="Vertical">
            <TextBlock Text="{Binding Source={StaticResource ResourceKey=mymodel}, Path=MyField2}"></TextBlock>     
            <Button Content="static test!" Click="Button_Click_1" />
        </StackPanel>
    </Grid>
</Window>

我的代码背后：

using System.Windows;

namespace WpfApplication1
{
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Button_Click_1(object sender, RoutedEventArgs e)
        {
            model2.MyField2 = "static!";
        }
    }
}

UI上的字段不会改变？

Answer 1

您需要通知对UI的更改，以便可以使用新值进行更新。

在您的情况下，您希望通知静态属性更改，因此您需要一个静态事件。问题是INotifyPropertyChanged接口需要一个成员事件，所以你不能这样做。

你最好的方法是实现Singleton模式：

SCHEDULE P0015D24#EP_DAILY_1_P
DRAFT
ON RUNCYCLE SIMPLE1 07/31/2004,09/30/2006,02/10/2007
EXCEPT RUNCYCLE CALENDAR2 PEATOFF
PRIORITY 0
:
P0015D24#EP_EA012_BFR

P0015D24#EP_EA012_N
 FOLLOWS EP_EA012_BFR
END

SCHEDULE P0015D24#EP_DAILY_2
ON RUNCYCLE RULE1 VALIDTO 10/02/2013 "FREQ=DAILY"
EXCEPT RUNCYCLE CALENDAR2 PEATOFF
EXCEPT RUNCYCLE CALENDAR3 PTDLY
EXCEPT RUNCYCLE CALENDAR5 TWS85OFF
EXCEPT RUNCYCLE EXCLUDE
  01/20/2007,02/10/2007,03/10/2007,04/21/2007,05/12/2007,06/09/2007,07/21/2007,08/11/2007,
  12/23/2007,12/24/2007,12/31/2007,01/19/2008,02/09/2008,01/01/2009,02/07/2009,05/22/2009,
  05/25/2009,07/02/2009,07/03/2009,07/04/2009,07/05/2009,09/04/2009,09/05/2009,09/07/2009,
  12/24/2009,12/25/2009,01/01/2010,03/20/2010,04/10/2010,09/06/2010,06/11/2011,12/24/2012
AT 0400
CARRYFORWARD
FOLLOWS P0015D24#PEAT_BKUP_CYE.@
FOLLOWS P0015D24#PEAT_BKUP_MNTH.@
FOLLOWS P0015D24#PEAT_BKUP_SAT.@
FOLLOWS P0015D24#PEAT_BKUP_SATNOV.@
FOLLOWS P0015D24#PEAT_RESTR_POST.@
FOLLOWS P0015M00#PEAT_BATCH_DONE.@
FOLLOWS P0015M00#PEAT_REBOOT.@
FOLLOWS P0015D24#PEAT_BKUP_POST.UNRESTRICT_FPR02
FOLLOWS P0015D24#PEAT_BKUP_POST_S.SWITCH_LOG
FOLLOWS P0015D24#PEAT_BKUP_POST_Z.SWITCH_LOG
:
P0015D24#EP_BATCH_DT
END

然后让你的属性成为一个成员属性并绑定如下：

namespace WpfApplication1
{
    public class model2 : INotifyPropertyChanged
    {
        //private ctor so you need to use the Instance prop
        private model2() {}

        private string myField2;

        public string MyField2
        {

            get { return myField2; }
            set { 
                myField2 = value; 
                OnPropertyChanged("MyField2");
            }
        }

        private static model2 _instance;

        public static model2 Instance {
            get {return _instance ?? (_instance = new model2();)}
        }

        public event PropertyChangedEventHandler PropertyChanged;

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

代码背后：

<Window x:Class="WpfApplication1.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:WpfApplication1"       
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <Window.Resources>
        <local:model2 x:Key="mymodel"/>
    </Window.Resources>
    <Grid>
        <StackPanel Orientation="Vertical">
            <TextBlock Text="{Binding Source={x:Static local:model2.Instance}, Path=MyField2}"/>  
            <Button Content="static test!" Click="Button_Click_1" />
        </StackPanel>
    </Grid>
</Window>

Answer 2

使用Static扩展来绑定TextBlocks文本属性：

<TextBlock Text="{Binding Source={Static MyModel.MyField2}, Mode=TwoWay">

但是Property仍然必须引发PropertyChanged事件。我理解你使用静态字段的原因是能够从其他地方设置值。你有没有想过使用消息呢？查看MVVM Light工具包和信使。这将解耦两个组件

Answer 3

我认为静态属性不是你想要使用的，从评论我可以推断你只是用来使你的程序工作。以下是完整的工作代码。

<强>的App.xaml

删除代码StartupUri="MainWindow.xaml，而不是在代码隐藏中实例化MainWindow以提供DataContext。

<强> App.xaml.cs

此处我们将Model2的对象指定为Window.DataContext，然后显示该窗口。

public partial class App : Application
    {
        public App()
        {
            Model2 model = new Model2();
            MainWindow window = new MainWindow();
            window.DataContext = model;
            window.Show();
        }
    }

<强> MainWindow.xaml.cs

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

        private void ButtonBase_OnClick(object sender, RoutedEventArgs e)
        {
            //We get hold of `DataContext` object
            var model = this.DataContext as Model2; 
            model.MyField2 = "Hello World";
        }
    }

<强>型号：

public class Model2 : INotifyPropertyChanged
    {

        private string _myField2;

        public string MyField2
        {
            get { return _myField2; }
            set
            {
                _myField2 = value;
                OnPropertyChanged("MyField2");
            }
        }

        protected void OnPropertyChanged(string name)
        {
            PropertyChangedEventHandler handler = PropertyChanged;
            if (handler != null)
            {
                handler(this, new PropertyChangedEventArgs(name));
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
    }

<强> MainWindow.xaml

<Window x:Class="WpfApplication2.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">
    <Grid>
        <StackPanel Orientation="Vertical">
            <TextBlock Text="{Binding MyField2}"></TextBlock>
            <Button Content="static test!" Click="ButtonBase_OnClick" />
        </StackPanel>
    </Grid>
</Window>

我查了一下，确实有效！

我的静态模型/属性没有绑定到我的UI

3 个答案: