DataGridTemplateColumn获取单元格的值

Question

我正在使用WPF Toolkit中的WPF DataGrid。

我在我的DataGrid中添加了一个模板列，它在每个单元中有一个CheckBox。现在我该如何访问这些单元格中的值？

DataGrid我的其他专栏来自DataSet。我可以访问这些，但我无法获得DataGridTemplateColumn的值，我将其添加到DataGrid。

任何人有任何想法？

Answer 1

你现在把东西拉出视觉树。这就是艰苦的工作，你不能找到绑定，因为它被埋在了单元格模板中。我所做的是为这种东西添加我自己的专栏，这个专栏是从DataGridBoundColumn派生的，这意味着它与所有其他专栏一样具有绑定功能：（我前一段时间写过，它可能会在某些方面看到）我只是使用直接绑定。我没有设置单元格模板，我可以使用DataTemplate，我更喜欢。

public class DataGridReadOnlyObjectDisplayColumn : DataGridBoundColumn { 

     public DataGridReadOnlyObjectDisplayColumn() { 
     //set as read only, 
     this.IsReadOnly = true; 
     } 


     /// <summary> 
     /// Gets and Sets the Cell Template for this column 
     /// </summary> 
     public DataTemplate CellTemplate { 
     get { return (DataTemplate)GetValue(CellTemplateProperty); } 
     set { SetValue(CellTemplateProperty, value); } 
     } 

     // Using a DependencyProperty as the backing store for CellTemplate. This enables animation, styling, binding, etc... 
     public static readonly DependencyProperty CellTemplateProperty = 
      DependencyProperty.Register("CellTemplate", typeof(DataTemplate), typeof(DataGridReadOnlyObjectDisplayColumn), new UIPropertyMetadata(null)); 



     protected override System.Windows.FrameworkElement GenerateElement(DataGridCell cell, object dataItem) { 
     //create the simple field text block 
     ContentControl contentControl = new ContentControl(); 

     contentControl.Focusable = false; 

     //if we have a cell template use it 
     if (this.CellTemplate != null) { 
      contentControl.SetValue(ContentControl.ContentTemplateProperty, this.CellTemplate); 
     } 

     //set the binding 
     ApplyBinding(contentControl, ContentPresenter.ContentProperty); 

     //return the text block 
     return contentControl; 
     } 

     /// <summary> 
     ///  Assigns the Binding to the desired property on the target object. 
     /// </summary> 
     internal void ApplyBinding(DependencyObject target, DependencyProperty property) { 
     BindingBase binding = Binding; 

     if (binding != null) { 
      BindingOperations.SetBinding(target, property, binding); 
     } 
     else { 
      BindingOperations.ClearBinding(target, property); 
     } 
     } 

     protected override System.Windows.FrameworkElement GenerateEditingElement(DataGridCell cell, object dataItem) { 
     //item never goes into edit mode it is a read only column 
     return GenerateElement(cell, dataItem); 
     } 
    } 

现在，如果您可以到达列，您可以进入列的绑定。如果你可以到达单元格，那么你可以找到数据项目（行数据）。那么我所做的就是遵循绑定来获取单元格的值。它真的是效率低下，而且它是一个黑客。但它的工作原理。遵循绑定我使用这个。

private Object GetCellValue(Binding columnBinding, object dataSource) { 

    Object valueField = null; 

    if (columnBinding != null) { 
     BindingEvaluator bindingEvaluator = new BindingEvaluator(); 

     //copy the binding 
     Binding binding = new Binding(); 
     binding.Path = columnBinding.Path; 
     binding.Source = dataSource; 

     //apply the binding 
     BindingOperations.SetBinding(bindingEvaluator, BindingEvaluator.BindingValueProperty, binding); 

     //get the current cell item 
     valueField = bindingEvaluator.BindingValue as IValueField; 
    } 

    return valueField; 
    } 

最后一块是所谓的BindingEvaluator一个辅助类，其中有一个DP，我使用遵循结合

public class BindingEvaluator : DependencyObject { 

     /// <summary> 
     /// Gets and Sets the binding value 
     /// </summary> 
     public Object BindingValue { 
     get { return (Object)GetValue(BindingValueProperty); } 
     set { SetValue(BindingValueProperty, value); } 
     } 

     // Using a DependencyProperty as the backing store for BindingValue. This enables animation, styling, binding, etc... 
     public static readonly DependencyProperty BindingValueProperty = 
      DependencyProperty.Register("BindingValue", typeof(Object), typeof(BindingEvaluator), new UIPropertyMetadata(null)); 
    } 

和我叫它像这样：

var valueField = this.GetCellValue(column.Binding as Binding, datagrid.CurrentCell.Item);