WPF 根据 ObservableCollection<T> 项选择组合框项

Posted 2023-04-01

【中文标题】WPF 根据 ObservableCollection<T> 项选择组合框项

【英文标题】：WPF select combox item according to ObservableCollection<T> item

【发布时间】：2021-12-23 02:16:48

【问题描述】：

我不知道怎么问这个问题，但我会尽力而为。 我有绑定到 GridView 的 ObservableCollection，并且 GridView 有一个带有组合框的列，我需要在用 ObservableCollection 中的数据填充 gridview 以自动从组合框中选择项目。

XAML

<DataGrid x:Name="dg" AutoGenerateColumns="False">
                <DataGrid.Columns>
                    <DataGridTextColumn Header="Date"></DataGridTextColumn>
                    <DataGridTextColumn Header="Description"></DataGridTextColumn>
                    <DataGridTemplateColumn Header="Status" Width="100">
                        <DataGridTemplateColumn.CellTemplate>
                            <DataTemplate>
                                <ComboBox Name="cb" SelectedItem="Binding Path=Status" SelectionChanged="cb_SelectionChanged" ItemsSource="Binding Source=local:EnumBindingSourceExtention x:Type local:status"/>
                            </DataTemplate>
                        </DataGridTemplateColumn.CellTemplate>
                    </DataGridTemplateColumn>
                </DataGrid.Columns>
            </DataGrid>

MainWindow.xaml.cs

    public partial class MainWindow : Window
    
        public ObservableCollection<Record> TasksList = new ObservableCollection<Record>();
        public string DbDoc;
        public MainWindow()
        
            InitializeComponent();
            this.DataContext = this;
        

        private void AddRecord(Record task)
        
            TasksList.Add(task);
        

        private void Window_Loaded(object sender, RoutedEventArgs e)
        
            DbDoc = System.IO.Path.Combine(Directory.GetCurrentDirectory(), "records.xml");
            if (File.Exists(DbDoc))
            
                using (StreamReader reader = new StreamReader(DbDoc))
                
                    XmlSerializer serializer = new XmlSerializer(typeof(Records));
                    Records records = (Records)serializer.Deserialize(reader);
                    records.RecordsList.ForEach(a=>TasksList.Add(a));
                    dg.ItemsSource = TasksList;
                
            
        
    
    [XmlRoot("Records")]
    public class Records
    
        [XmlElement("Record", typeof(Record))]
        public List<Record> RecordsList  get; set; 
    
    public class Record
    
        [XmlElement("Date")]
        public string Date  get; set; 
        [XmlElement("Description")]
        public string Description  get; set; 
        [XmlElement("Status")]
        public string Status  get; set; 

    
        public class EnumBindingSourceExtention : MarkupExtension
    
        public Type EnumType  get; private set; 

        public EnumBindingSourceExtention(Type enumType)
        
            if (enumType == null || !enumType.IsEnum)
            
                throw new Exception("EnumType is null or not EnumType");
            
            this.EnumType = enumType;
        

        public override object ProvideValue(IServiceProvider serviceProvider)
        
            return Enum.GetValues(EnumType);
        
    
    public enum status
    
        New,
        Old
    

所以，我需要在窗口加载时将TasksList 绑定到数据网格dg 以获取Status 字符串并从组合框中选择项目。

有什么帮助吗？

【参考方案1】：

将Record类的Status属性类型更改为status（枚举类型）或将ComboBox的ItemsSource属性设置为IEnumerable<string>：

public override object ProvideValue(IServiceProvider serviceProvider)

    return Enum.GetValues(EnumType).Cast<object>().Select(x => x.ToString());

类型必须匹配。您不能将string 属性设置为枚举（enum）值。