不能創建動態網格

Question

我是新來WPF MVVM我創建動態grid.my代碼如下

public class Property : INotifyPropertyChanged 
{ 
    public Property(string name, object value) 
    { 
     Name = name; 
     Value = value; 
    } 

    public string Name { get; private set; } 
    public object Value { get; set; } 

    public event PropertyChangedEventHandler PropertyChanged; 
} 
public class Record 
{ 
    private readonly ObservableCollection<Property> properties = new ObservableCollection<Property>(); 

    public Record(params Property[] properties) 
    { 
     foreach (var property in properties) 
      Properties.Add(property); 
    } 

    public ObservableCollection<Property> Properties 
    { 
     get { return properties; } 
    } 
} 

public class DataGridColumnsBehavior 
{ 

    public static readonly DependencyProperty BindableColumnsProperty = 
     DependencyProperty.RegisterAttached("BindableColumns", 
     typeof(ObservableCollection<DataGridColumn>), 
     typeof(DataGridColumnsBehavior), 
     new UIPropertyMetadata(null, BindableColumnsPropertyChanged)); 

    private static void BindableColumnsPropertyChanged(DependencyObject source, DependencyPropertyChangedEventArgs e) 
    { 
     DataGrid myDataGrid = source as DataGrid; 
     ObservableCollection<DataGridColumn> columns = e.NewValue as ObservableCollection<DataGridColumn>; 

     myDataGrid.Columns.Clear(); 
     if (columns == null) 
      return; 

     foreach (DataGridColumn column in columns) 
     { 
      myDataGrid.Columns.Add(column); 
     } 

     columns.CollectionChanged += (sender, e1) => 
     { 

     -----------// Others stuff 
} 

    private void FillData() 
    { 
     List<DataClass> MyClass = new List<DataClass>(); 
     records = new ObservableCollection<Record>(); 
     records.Add(new Record(new Property("FirstName", "Name1"), new Property("LastName", "Name2"))); 
     records.Add(new Record(new Property("FirstName", "Name3"), new Property("LastName", "Name4"))); 

     var columns = records.First() 
        .Properties 
        .Select((x, i) => new { Name = x.Name, Index = i }) 
        .ToArray(); 

     ColumnCollection = new ObservableCollection<DataGridColumn>(); 
     foreach (var column in columns) 
     { 
      var binding = new Binding(string.Format("Properties[{0}].Value", column.Index)); 

      ColumnCollection.Add(new DataGridTextColumn() { Header = column.Name, Binding = binding }); 
     } 
     MyClass.Add(new DataClass() { HeaderName = "HeaderVal", GridVal = records }); 
     myListBox.ItemsSource = MyClass; 
    } 

，並在我的主窗口我有

 <Grid> 
    <ListBox Width="400" Margin="10" x:Name="myListBox"> 
     <ListBox.ItemTemplate> 
     <DataTemplate> 
       <Expander Header="Header1" IsExpanded="False"> 
        <StackPanel> 
         <DataGrid 
          x:Name="dataGrid" 
          local:DataGridColumnsBehavior.BindableColumns="{Binding ColumnCollection}" 
          AutoGenerateColumns="False" 
          ItemsSource="{Binding Path=records}"/> 
        </StackPanel> 
       </Expander> 
     </DataTemplate> 
     </ListBox.ItemTemplate> 
    </ListBox> 
</Grid> 

但網格是不可見。我錯過了什麼？

Answer 1

你被

new DataClass() { HeaderName = "HeaderVal", GridVal = records } 

創建一個數據類實例這意味着，「記錄」是由GridVal屬性訪問。因此，您的結合應該是

ItemsSource="{Binding Path=GridVal}" 

此外，ColumnCollection也應該在類數據類的屬性，以使這種結合工作：

local:DataGridColumnsBehavior.BindableColumns="{Binding ColumnCollection}" 

否則，您必須指定一個Source或RelativeSource明確綁定。

您應該在Visual Studio的輸出窗口中觀察到綁定錯誤消息。

它看起來也很可疑，你的Property類實現INotifyPropertyChanged，但從不引發PropertyChanged事件。