在DataGrid中使用CheckBox选择行时典型的错误就是CheckBox没有Binding到任何属性上，这样的话当拖动滚动条时CheckBox.IsChecked就会乱掉，如Demo中左边那个DataGrid所示。最直观的解决方法是禁用DataGrid的滚动条，或者在绑定的数据上添加一个用于绑定CheckBox的bool属性。

其实只要在DataGrid.LoadingRow事件中将CheckBox的DataContext设定为另外一个Object，就不需要牺牲DataGrid的高效能，也不需要改变原有数据的结构。具体实现如下：

 

 

public class MyDataGrid : DataGrid     {
            private const string HeaderCheckBoxName = "select_column_checkbox";         private Dictionary
     
       _markObjects;         private DataGridTemplateColumn _selectColumn;         private CheckBox _selectCheckBox;         public MyDataGrid()         {
                _markObjects = new Dictionary
      
       ();             _selectColumn = new DataGridTemplateColumn();             _selectColumn.HeaderStyle = GetHeaderStyle();             _selectColumn.CellTemplate = GetCellTemplate();             this.Columns.Insert(0, _selectColumn);             this.SizeChanged += new SizeChangedEventHandler(OnSizeChanged);         }         public void SelectAll()         {
                if (_selectCheckBox != null)                 _selectCheckBox.IsChecked = true;             SetAllSelectedStates(true);         }         public void UnselectAll()         {
                if (_selectCheckBox != null)                 _selectCheckBox.IsChecked = false;             SetAllSelectedStates(false);         }         public List
       
         GetSelectedItems
        
         ()         {
                List
         
           result = new List
          
           (); if (ItemsSource != null) { var enu = ItemsSource.GetEnumerator(); while (enu.MoveNext()) { if (GetMarkObject(enu.Current).Selected) result.Add((T)enu.Current); } } return result; } protected override void OnLoadingRow(DataGridRowEventArgs e) { base.OnLoadingRow(e); object dataContext = e.Row.DataContext; FrameworkElement element = _selectColumn.GetCellContent(e.Row); element.DataContext = GetMarkObject(dataContext); } private Style GetHeaderStyle() { Style style = new System.Windows.Style(); style.TargetType = typeof(ContentControl); StringBuilder tmp = new StringBuilder(); tmp.Append("
           
            "); tmp.Append(string.Format("
            ", HeaderCheckBoxName)); tmp.Append("
           "); DataTemplate contentTemplate = XamlReader.Load(tmp.ToString()) as DataTemplate; style.Setters.Add(new Setter(ContentControl.ContentTemplateProperty, contentTemplate)); return style; } private DataTemplate GetCellTemplate() { StringBuilder tmp = new StringBuilder(); tmp.Append("
           
            "); tmp.Append("
            "); tmp.Append("
           "); return XamlReader.Load(tmp.ToString()) as DataTemplate; } private MarkObject GetMarkObject(Object obj) { if (_markObjects.ContainsKey(obj) == false) { MarkObject markObject; markObject = new MarkObject(); _markObjects.Add(obj, markObject); } return _markObjects[obj]; } private void OnSizeChanged(object sender, SizeChangedEventArgs e) { _selectCheckBox = this.GetChild
           
            (HeaderCheckBoxName); if (_selectCheckBox == null) return; _selectCheckBox.Checked += (sender2, e2) => SetAllSelectedStates(true); _selectCheckBox.Unchecked += (sender2, e2) => SetAllSelectedStates(false); } private void SetAllSelectedStates(bool value) { if (ItemsSource == null) return; var enu = ItemsSource.GetEnumerator(); while (enu.MoveNext()) { GetMarkObject(enu.Current).Selected = value; } } }
           
          
         
        
       
      
     

其中MarkObject是一个继承INotifyPropertyChanged的类,包含Selected属性，这样更改Selected时可以更新UI。在构造函数中直接插入了个模板列，模板列使用XamlReader.Load(string str)方法直接在代码中创建模板。至于列头的CheckBox则在SizeChanged事件时才可以通过VisualTreeHelper.GetChild递归找到。

 

原文：上面有效果图，效果图怎么实现的