Question

这是我的代码（我的ViewModel：

                        NamesDB.Open();
                        string NamesCommand = "SELECT * FROM [Country]";
                        OleDbDataAdapter dr = new OleDbDataAdapter(new OleDbCommand(NamesCommand, NamesDB));
                        DataSet ds = new DataSet();
                        dr.Fill(ds);
                        var empList = ds.Tables[0].AsEnumerable().Select(dataRow => new Country { Name = dataRow.Field<string>("NameCountry")}).ToList();
                        Countries = empList;
                        NamesDB.Close();


    public List<Country> Countries { get; set; }

    public class Country
    {
        public string Name { get; set; }
    }

我正在从数据库中读取整个列，并将其存储在“ empList”中。我想我就是这么做的。

我有一个组合框，想要将源绑定到XAML中的国家/地区：

 ItemsSource="{Binding Countries}"

但是我没有得到国家的名字，我也不知道我做错了什么

请帮助：（

预先感谢

Answer 1

我认为这就是您要完成的工作。

首先，您的组合框应该看起来像这样。

<ComboBox DisplayMemberPath="Name" ItemsSource="{Binding Countries}"></ComboBox>

模型可能看起来像这样：

public class Country
{
    public string Name { get; set; }
}

然后，您的viewModel应该类似于：

public class MainWindowViewModel : INotifyPropertyChanged
{

    public MainWindowViewModel()
    {
        GetData();
    }

    private List<Country> _countries;

    public event PropertyChangedEventHandler PropertyChanged;

    [NotifyPropertyChangedInvocator]
    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }

    public List<Country> Countries
    {
        get => _countries;
        set
        {
            _countries = value;
            OnPropertyChanged();
        }

    }

    private void GetData()
    {
        // call database here
        var countries = new List<Country>()
        {
            new Country() {Name = "Usa"},
            new Country() {Name = "Mexico"},
        };

        Countries = countries;
    }
}public class MainWindowViewModel : INotifyPropertyChanged
{

    public MainWindowViewModel()
    {
        GetData();
    }

    private List<Country> _countries;

    public event PropertyChangedEventHandler PropertyChanged;

    [NotifyPropertyChangedInvocator]
    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }

    public List<Country> Countries
    {
        get => _countries;
        set
        {
            _countries = value;
            OnPropertyChanged();
        }

    }

    private void GetData()
    {
        // call database here
        var countries = new List<Country>()
        {
            new Country() {Name = "Usa"},
            new Country() {Name = "Mexico"},
        };

        Countries = countries;
    }
}

使用ViewModel绑定ComboBox源（mvvm wpf）

1 个答案: