我有一个DataGrid包含来自设置对象的信息.目前,DataGrid和设置对象之间存在双向绑定.但是,我想在其中放置一个“保存”按钮,仅在用户单击“保存”按钮时将DataGrid中所做的更改绑定到对象.但是,我不知道如何使用我的DataGrid为我的特定情况调用UpdateSource().
这是我的xaml.cs代码:
public void LoadDataFields(Data d)
{
Grid1.ItemsSource = d.Fields;
}
private void SaveChanges(object sender, RoutedEventArgs e)
{
BindingExpression be = Grid1.GetBindingExpression(DataGrid.ItemsSourceProperty);
be.UpdateSource();
}
这是我的xaml代码:
<DataGrid x:Name="Grid1"
IsReadOnly="False"
Height="360"
Margin="20,15,20,15"
VerticalAlignment="Top"
AutoGenerateColumns="False"
CanUserAddRows="False" SelectionUnit="Cell"
ItemsSource="{Binding data}"
>
<DataGrid.Columns>
<DataGridTemplateColumn Header="Field">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBox Text="{Binding Path=name, Mode=TwoWay, UpdateSourceTrigger=Explicit}"/>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn Header="Length of Field">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBox Text="{Binding Path=length, Mode=TwoWay, UpdateSourceTrigger=Explicit}"/>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
是否有一种简单的方法来调用UpdateSource(),以便仅在单击“保存”按钮时才进行绑定?我的猜测是我只是为GetBindingExpression方法添加了错误的属性.
解决方法:
是的,有办法,但这不是一个非常简单的方法.首先,您需要2个辅助方法:
public static T GetVisualChild<T>(Visual parent) where T : Visual
{
Visual visual;
T child = default(T);
int childrenCount = VisualTreeHelper.GetChildrenCount(parent);
for (int i = 0; i < childrenCount; i++)
{
visual = (Visual)VisualTreeHelper.GetChild(parent, i);
child = visual as T;
if (child == null)
{
child = GetVisualChild<T>(visual);
}
if (child != null)
{
break;
}
}
return child;
}
public T FindVisualChild<T>(DependencyObject obj, string name) where T : DependencyObject
{
DependencyObject child;
FrameworkElement frameworkElement;
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
{
child = VisualTreeHelper.GetChild(obj, i);
frameworkElement = child as FrameworkElement;
if (child != null && child is T && frameworkElement != null && frameworkElement.Name == name)
{
return (T)child;
}
else
{
T childOfChild = FindVisualChild<T>(child, name);
if (childOfChild != null)
{
return childOfChild;
}
}
}
return null;
}
然后你必须给你的绑定控件命名.例如“textBox”:
<DataGridTemplateColumn Header="Field">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBox x:Name="textBox" Text="{Binding Path=name, Mode=TwoWay, UpdateSourceTrigger=Explicit}"/>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn Header="Length of Field">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBox x:Name="textBox" Text="{Binding Path=length, Mode=TwoWay, UpdateSourceTrigger=Explicit}"/>
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
然后在SaveChanges方法中,您可以使用以下代码:
private void SaveChanges(object sender, RoutedEventArgs e)
{
DataGridRow dataGridRow;
DataGridCellsPresenter dataGridCellsPresenter;
DataGridCell dataGridCell;
TextBox textBox;
BindingExpression bindingExpression;
for (int i = 0; i < Grid1.Items.Count; i++)
{
dataGridRow = (DataGridRow)Grid1.ItemContainerGenerator.ContainerFromIndex(i);
dataGridCellsPresenter = GetVisualChild<DataGridCellsPresenter>(dataGridRow);
for (int j = 0; j < Grid1.Columns.Count; j++)
{
dataGridCell = (DataGridCell)dataGridCellsPresenter.ItemContainerGenerator.ContainerFromIndex(j);
textBox = FindVisualChild<TextBox>(dataGridCell, "textBox");
if (textBox != null)
{
bindingExpression = BindingOperations.GetBindingExpression(textBox, TextBox.TextProperty);
bindingExpression.UpdateSource();
}
}
}
}
我希望它可以帮到你.