Question

我创建了2个简单的类：

public class Car
{
    public int ID { get; set; }
    public string Name { get; set; }
    public string Model { get; set; }
    public string CheckInDateTime { get; set; }
}
public class CarDataSource
{
    private static ObservableCollection<Car> _myCars=new ObservableCollection<Car>();
    public  static ObservableCollection<Car> GetCars()
    {
        if(_myCars.Count==0)
        {
            _myCars.Add(new Car() { ID = 1, Name = "A", Model = "Yamaha", });
            _myCars.Add(new Car() { ID = 2, Name = "B", Model = "Toyota" });
            _myCars.Add(new Car() { ID = 3, Name = "C", Model = "Suzuki" });
        }
        return _myCars;
    }
}

在MainPage.xaml.cs中，我调用静态GetCars（）方法为MainPage.xaml连接CarViewModel：

public ObservableCollection<Car> CarViewModel = CarDataSource.GetCars();

最后绑定到xaml文件中的视图模型：

<Page
x:Class="BindingCommand.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:BindingCommand"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
DataContext="{Binding CarViewModel,RelativeSource={RelativeSource Self}}"
Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">

<Grid>
    <StackPanel>
        <ListView x:Name="myListView" ItemsSource="{Binding}">
            <ListView.ItemTemplate>
                <DataTemplate x:Name="dataTemplate">
                    <StackPanel Orientation="Horizontal">
                        <StackPanel Orientation="Vertical" Margin="0,0,20,0">
                            <TextBlock Text="{Binding Make}" FontSize="24"/>
                            <TextBlock Text="{Binding Model}" FontSize="24"/>
                        </StackPanel>
                        <Button Content="Check In"
                                Width="100"
                                Height="50"
                                Margin="0,0,20,0"/>
                        <TextBlock Text="{Binding CheckInDateTime}" FontSize="24"/>
                    </StackPanel>
                </DataTemplate>
            </ListView.ItemTemplate>

        </ListView>
    </StackPanel>
</Grid>

但是当我吵架并运行它时，它什么都没有给我看。但后来我修复了CarViewModel：

public ObservableCollection<Car> _CarViewModel = CarDataSource.GetCars();
    public ObservableCollection<Car> CarViewModel
    {
        get { return this._CarViewModel;} 
    }

它按照我想要的结果。我仍然不知道它是如何工作的：|

Answer 1

WPF / Xaml中的绑定始终针对属性进行解析。在第一种情况下，您有一个公共字段，因此绑定系统找不到路径“CarViewModel”的匹配项。如果您在调试器中运行时观察了输出窗口，那么可能存在绑定错误。

当您将其更改为属性时，绑定过程能够找到它并且它有效。

XAML：对绑定感到困惑

1 个答案: