Question

我有一个基于ObservableCollection Categories绑定到tbl_Category的组合框类别，其中包含两个属性CategoryName和CategoryDescription。现在，我想将SelectedValue的{{1}}添加到产品表属性ComboBox

在我的构造函数中：

Prod_Category

组合框xaml：

cb.DataContext = Categories;
this.DataContext = new tbl_Product();

在我的保存产品活动中：

<Combobox x:Name="cb" ItemSource="{Binding Categories}" DisplayMemberPath="CategoryName" SelectedValuePath="CategoryName" SelectedValue="{Binding Prod_Category,Mode=TwoWay}"/>

即使完成所有这些操作，我也会tbl_Product prod = (tbl_Product)this.DataContext; DataOperations.AddProduct(prod);到Prod_Category。

Answer 1

您应该使用SelectedItem而不是SelectedValue，请参阅this。

除了您愿意做的事情不是那么清楚之外，我已经尝试根据我的理解实施您所要求的内容

 public partial class MainWindow : Window,INotifyPropertyChanged
{
    private ObservableCollection<Category> _categories;
    public ObservableCollection<Category> Categories
    {
        get
        {
            return _categories;
        }

        set
        {
            if (_categories == value)
            {
                return;
            }

            _categories = value;
            OnPropertyChanged();
        }
    }
    private Category _prod_Category ;
    public Category Prod_Category
    {
        get
        {
            return _prod_Category;
        }

        set
        {
            if (_prod_Category == value)
            {
                return;
            }

            _prod_Category = value;
            OnPropertyChanged();
        }
    }
    public MainWindow()
    {
        InitializeComponent();
        this.DataContext = this;
        Categories=new ObservableCollection<Category>()
        {
            new Category()
            {
                CategoryName = "Name1",
                CategoryDescription = "Desc1"
            },new Category()
            {
                CategoryName = "Name2",
                CategoryDescription = "Desc2"
            }
        };
    }

    public void SaveButton_Click(object sender, RoutedEventArgs routedEventArgs)
    {
        if (Prod_Category!=null)
        {
            //add it to whatever you want

        }
    }


    public event PropertyChangedEventHandler PropertyChanged;
    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
    {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
    }
}

public class Category
{
    public String CategoryName { get; set; }
    public String CategoryDescription { get; set; }
}

和xaml

 <StackPanel>
    <ComboBox x:Name="cb" ItemsSource="{Binding Categories}" DisplayMemberPath="CategoryName" SelectedValuePath="CategoryName" SelectedItem="{Binding Prod_Category,Mode=TwoWay}"/>
    <Button Content="Save" Click="SaveButton_Click"></Button>
</StackPanel>

如果其中一个绑定属性发生任何更改，您应该考虑实施INotifyPropertyChanged接口来通知用户界面

WPF - 如何将选定值绑定到表模型

1 个答案: