以前写过几个方法实现这个功能，但最终还是选择了不继承DataGrid，所以再重新发布出来。
先显示最终结果，其中左边是错误的例子，右边才是正确的
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。最终的实现方法是自定义一个包含DataGrid的DataGridTemplateColumn，而不需要重写DataGrid，这样的坏处就是每次调用需要多写一局代码，如果不想这样就继承DataGrid然后把这句代码写进去。在DataGrid.Columns中加入自定义的Column,然后在代码中关联DataGrid和这个Colum，就完成了：
代码语言：javascript复制<sdk:DataGrid ItemsSource="{Binding}"
AutoGenerateColumns="False"
Grid.Column="1"
x:Name="TestDataGrid">
<sdk:DataGrid.Columns>
<local:DataGridSelectColumn />
<sdk:DataGridTextColumn Header="Name"
Binding="{Binding Name}"
Width="*" />
</sdk:DataGrid.Columns>
</sdk:DataGrid>TestDataGrid.EnableSelect();下面是这个DataGridSelectColumn的具体实现。创建一个UserControl然后把它改成DataGridTemplateColumn，这样好处是DataTemplate和Style中的FrameworkElement都可以轻松地获取。
代码语言：javascript复制<sdk:DataGridTemplateColumn xmlns:sdk="http://schemas.microsoft.com/winfx/2006/xaml/presentation/sdk"
x:Class="DataGridSelectSample.DataGridSelectColumn"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
d:DesignHeight="300"
d:DesignWidth="400">
<sdk:DataGridTemplateColumn.HeaderStyle>
<Style TargetType="ContentControl">
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<CheckBox Content="Select All"
VerticalContentAlignment="Center"
VerticalAlignment="Center"
Loaded="OnHeaderCheckBoxLoaded"/>
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
</sdk:DataGridTemplateColumn.HeaderStyle>
<sdk:DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<CheckBox IsChecked="{Binding IsSelected,Mode=TwoWay}"
VerticalAlignment="Center"
HorizontalAlignment="Center" />
</DataTemplate>
</sdk:DataGridTemplateColumn.CellTemplate>
</sdk:DataGridTemplateColumn>public partial class DataGridSelectColumn : DataGridTemplateColumn
{
private DataGrid _ownerDataGrid;
private CheckBox _headerCheckBox;
private Dictionary<object, MarkObject> _markObjects;
public event EventHandler SelectedItemChanged;
public DataGridSelectColumn()
{
InitializeComponent();
IsReadOnly = true;
_markObjects = new Dictionary<object, MarkObject>();
}
public DataGrid OwnerDataGrid
{
get { return _ownerDataGrid; }
set
{
_ownerDataGrid = value;
_ownerDataGrid.LoadingRow = OnLoadingRow;
}
}
public void SelecteAll()
{
if (_headerCheckBox != null)
_headerCheckBox.IsChecked = true;
SetAllSelectedStates(true);
}
public void UnselectAll()
{
if (_headerCheckBox != null)
_headerCheckBox.IsChecked = false;
SetAllSelectedStates(false);
}
public List<T> GetSelectedItems<T>()
{
List<T> result = new List<T>();
if (_ownerDataGrid.ItemsSource != null)
{
var enu = _ownerDataGrid.ItemsSource.GetEnumerator();
while (enu.MoveNext())
{
if (GetMarkObject(enu.Current).IsSelected)
result.Add((T)enu.Current);
}
}
ClearItems();
return result;
}
public void SetSelectedItems(IList items)
{
if (_ownerDataGrid.ItemsSource == null)
return;
var enu = _ownerDataGrid.ItemsSource.GetEnumerator();
while (enu.MoveNext())
{
GetMarkObject(enu.Current).IsSelected = items.Contains(enu.Current);
}
}
private void ClearItems()
{
var enu = _ownerDataGrid.ItemsSource.GetEnumerator();
List<object> list = new List<object>();
while (enu.MoveNext())
{
list.Add(enu.Current);
}
List<object> removableObjects = new List<object>();
foreach (var item in _markObjects)
{
if (list.Contains(item.Key) == false)
{
removableObjects.Add(item.Key);
}
}
for (int i = 0; i < removableObjects.Count; i )
{
_markObjects.Remove(removableObjects[i]);
}
}
private void OnHeaderCheckBoxLoaded(object sender, RoutedEventArgs e)
{
_headerCheckBox = sender as CheckBox;
_headerCheckBox.Loaded -= OnHeaderCheckBoxLoaded;
_headerCheckBox.Checked = (s2, e2) => SetAllSelectedStates(true);
_headerCheckBox.Unchecked = (s2, e2) => SetAllSelectedStates(false);
}
private void OnLoadingRow(object sender, DataGridRowEventArgs e)
{
object dataContext = e.Row.DataContext;
FrameworkElement element = this.GetCellContent(e.Row);
element.DataContext = GetMarkObject(dataContext);
}
private void SetAllSelectedStates(bool value)
{
if (_ownerDataGrid.ItemsSource == null)
return;
var enu = _ownerDataGrid.ItemsSource.GetEnumerator();
while (enu.MoveNext())
{
GetMarkObject(enu.Current).IsSelected = value;
}
ClearItems();
}
private MarkObject GetMarkObject(Object obj)
{
if (_markObjects.ContainsKey(obj) == false)
{
MarkObject markObject;
markObject = new MarkObject();
_markObjects.Add(obj, markObject);
markObject.PropertyChanged = (s, e) =>
{
if (e.PropertyName == "IsSelected")
{
if (SelectedItemChanged != null)
{
SelectedItemChanged(this, EventArgs.Empty);
}
}
};
}
return _markObjects[obj];
}
}其中MarkObject是一个继承INotifyPropertyChanged的类,包含Selected属性，这样更改IsSelected时可以更新UI。
最后加上DataGridExtensions 是为了方便调用。
代码语言：javascript复制View Code
public static class DataGridExtensions
{
internal static DataGridSelectColumn GetSelectColumn(this DataGrid dataGrid)
{
DataGridSelectColumn result = null;
for (int i = 0; i < dataGrid.Columns.Count; i )
{
result = dataGrid.Columns[i] as DataGridSelectColumn;
if (result != null)
break;
}
return result;
}
public static void EnableSelect(this DataGrid dataGird)
{
var column = GetSelectColumn(dataGird);
column.OwnerDataGrid = dataGird;
}
public static void SelectAll(this DataGrid dataGrid)
{
DataGridSelectColumn column = GetSelectColumn(dataGrid);
if (column == null)
throw new Exception("No Select Column");
column.SelecteAll();
}
public static void UnselectAll(this DataGrid dataGrid)
{
DataGridSelectColumn column = GetSelectColumn(dataGrid);
if (column == null)
throw new Exception("No Select Column");
column.UnselectAll();
}
public static List<T> GetSelectedItems<T>(this DataGrid dataGrid)
{
DataGridSelectColumn column = GetSelectColumn(dataGrid);
if (column == null)
throw new Exception("No Select Column");
return column.GetSelectedItems<T>();
}
public static void SetSelectedItems(this DataGrid dataGrid, IList items)
{
DataGridSelectColumn column = GetSelectColumn(dataGrid);
if (column == null)
throw new Exception("No Select Column");
column.SetSelectedItems(items);
}
}附上完整源码，欢迎指正。
/Files/dino623/DataGridSelectSample.zip
