Question

我正在尝试在Windows 10 C＃应用程序中实现新的编译绑定，我遵循了MSVA视频和绑定工作，但是当我进行一些更改时，UI不会更新。例如，当我在profilesView中添加新配置文件时，或者当我在profileview中更新名称时。这是我的代码：

profile.cs

public string Name { get; set; }
public string Surname { get; set; }
public string FullName { get; set; }

profileviewmodel.cs

public class ProfileViewModel : BindableBase
{
    private Profile defaultProfile = new Profile { };
    public Profile DefaultProfile {
        get { return this.defaultProfile; }
        set { this.SetProperty(ref this.defaultProfile, value); }
    }

profilesviewmodel.cs

     public class ProfilesViewModel : BindableBase
{
    private ObservableCollection<Profile> profiles = new ObservableCollection<Profile> { };
    public ObservableCollection<Profile> Profiles {
        get { return this.profiles; }
        set { this.SetProperty(ref this.profiles, value); }
    }

profilespage.xaml

    xmlns:vm="using:vCard.ViewModels">

<Page.DataContext>
    <vm:ProfilesViewModel/>
</Page.DataContext>

<ListView ItemsSource="{x:Bind ViewModel.Profiles}" xmlns:model="using:vCard.Models">
    <ListView.ItemTemplate>
        <DataTemplate x:DataType="model:Profile">
            <Grid>
                <TextBlock Text="{x:Bind Name, Mode=TwoWay}"/>
            </Grid>
        </DataTemplate>
    </ListView.ItemTemplate>
</ListView>

profilespage.xaml.cs

  public ProfilesViewModel ViewModel { get; set; }
    public ProfilesPage2()
    {
        this.ViewModel = new ProfilesViewModel();

        this.InitializeComponent();            

        this.DataContextChanged += (s,e) => { ViewModel = DataContext as ProfilesViewModel; };            

        ViewModel.Profiles.Add(new Profile { Name = "aaa" });
    }

profilepage.xaml

xmlns:vm="using:vCard.ViewModels">

<Page.DataContext>
    <vm:ProfileViewModel/>
</Page.DataContext>

<StackPanel>
    <TextBlock Text="Profile" Margin="10"/>
    <TextBox Text="{Binding DefaultProfile.Name, Mode=TwoWay}" TextChanged="Name_TextChanged"/>
    <TextBox Text="{Binding DefaultProfile.Surname, Mode=TwoWay}" TextChanged="Name_TextChanged"/>
    <TextBox Text="{Binding DefaultProfile.FullName, Mode=TwoWay}"/>
</StackPanel>

profilepage.xaml.cs

    public ProfileViewModel ViewModel { get; set; }
    public ProfilePage2()
    {
        this.ViewModel = new ProfileViewModel();

        this.InitializeComponent();

        // Setup the DataContext 
        this.DataContextChanged += (s, e) => { ViewModel = DataContext as ProfileViewModel; };

        ViewModel.DefaultProfile.Name = "aaa";

    }

感谢

Answer 1

以下是根据您的方案进行操作的方法。我有点不同的方法但很清楚，我希望理解：

profile.cs ***仅当您将绑定UI控件上的属性时才使用INotifyPropertyChanged实现

public class Profile : INotifyPropertyChanged
{
    public string name;
    public string surname;
    public string fullname;


    public string Name { get { return name; } set { name = value; OnPropertyChanged("Name"); } }

    public string Surname { get { return surname; } set { surname = value; OnPropertyChanged("Surname"); } }

    public string FullName { get { return fullname; } set { fullname = value; OnPropertyChanged("Fullname"); } }

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

profileviewmodel.cs **已更新

public ObservableCollection<Profile> Profiles { get; set;}

public ProfilesViewModel()
{
    Profiles = new ObservableCollection<Profile>();
}

profilepage.xaml

<ListView ItemsSource="{Binding Profiles}" >
    <ListView.ItemTemplate>
        <DataTemplate>
            <Grid>
                <!-- The TwoWay binding is for updating the object through UI -->
                <!-- If you need TwoWay you must use TextBox not TextBlock -->
                <TextBlock Text="{Binding Name, Mode=OneWay}"/>
            </Grid>
        </DataTemplate>
    </ListView.ItemTemplate>
</ListView>

profilepage.xaml.cs

public ProfilesViewModel ViewModel = new ProfilesViewModel();
public ProfilePage()
{
    this.InitializeComponent();
    this.DataContext = ViewModel;

    ViewModel.Profiles.Add(new Profile { Name = "aaa" });
    ViewModel.Profiles.Add(new Profile { Name = "bbb" });

}

Answer 2

在代码中尝试实现INotifyPropertyChanged

profile.cs

public class Profile : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    public void NotifyPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this,
                new PropertyChangedEventArgs(propertyName));
        }
    }

    private string name = string.Empty;
    public string Name
    {
        get { return name; }
        set { name = value; NotifyPropertyChanged("Name"); }
    }
    private string surname = string.Empty;
    public string Surname
    {
        get { return surname; }
        set { surname = value; NotifyPropertyChanged("Surname"); }
    }
    private string fullName = string.Empty;
    public string FullName
    {
        get { return fullName; }
        set { fullName = value; NotifyPropertyChanged("FullName"); }
    }
}

windows 10编译绑定最佳实践

2 个答案: