我正在尝试为DataGrid实现列选择器功能，如果我尝试将列的标题内容定义为不仅仅是字符串，那么我遇到了问题。下面是一个非常简化的示例，其中所有样式，视图模型，绑定等都被剥离。
有3列：
第一列使用字符串作为标题。 第二列尝试使用工具提示将标题内容设置为Label。 第三列绑定使用工具提示将标题内容设置为TextBlock。
单击A列的切换可见性按钮可以正常工作。列B和C的“切换可见性”按钮会导致InvalidOperationException，并显示消息“指定的元素已经是另一个元素的逻辑子元素。请先断开它。”
<Window x:Class="DataGridColumnChoosing.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<StackPanel Orientation="Horizontal" Margin="0,10">
<TextBlock Margin="15, 0">Toggle Visibility:</TextBlock>
<Button Click="ToggleA">Column A</Button>
<Button Click="ToggleB">Column B</Button>
<Button Click="ToggleC">Column C</Button>
</StackPanel>
<!-- Main Fuel Mileage Datagrid -->
<DataGrid x:Name="mySampleDataGrid" Grid.Row="1"
AutoGenerateColumns="False" CanUserSortColumns="False" CanUserResizeRows="False" CanUserAddRows="False"
GridLinesVisibility="All" RowHeaderWidth="0">
<DataGrid.Columns>
<DataGridTemplateColumn x:Name="colA" Width="40*" IsReadOnly="True" Header="Column A">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock />
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn x:Name="colB" Width="40*" IsReadOnly="True" >
<DataGridTemplateColumn.Header>
<Label Content="Column B" ToolTip="A short explanation of Column B"/>
</DataGridTemplateColumn.Header>
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock />
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn x:Name="colC" Width="40*" IsReadOnly="True" >
<DataGridTemplateColumn.Header>
<TextBlock Text="Column C" ToolTip="A short explanation of Column C " />
</DataGridTemplateColumn.Header>
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock />
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
</Grid>
在此示例中切换可见性的按钮的简单点击事件处理程序只是修改列的可见性。
private void ToggleA(object sender, RoutedEventArgs e)
{
colA.Visibility = colA.Visibility == System.Windows.Visibility.Visible ? System.Windows.Visibility.Hidden : System.Windows.Visibility.Visible;
}
private void ToggleB(object sender, RoutedEventArgs e)
{
colB.Visibility = colB.Visibility == System.Windows.Visibility.Visible ? System.Windows.Visibility.Hidden : System.Windows.Visibility.Visible;
}
private void ToggleC(object sender, RoutedEventArgs e)
{
colC.Visibility = colC.Visibility == System.Windows.Visibility.Visible ? System.Windows.Visibility.Hidden : System.Windows.Visibility.Visible;
}
谢谢大家。
答案 0 :(得分：11)
当我在我的资源中定义了一个控件并试图在多个控件的内容区域中使用它时，我遇到过这个问题。这不起作用，因为控件只能属于一个父级。
相反，我需要定义一个包含我想要的控件的模板，并直接设置我的对象的模板而不是内容。
你对@ Gimno的回答的评论让我觉得情况确实如此。
尝试更改它，而不是直接在DataGrid.Header的内容中设置Label / TextBox，将DataGrid.HeaderTemplate设置为包含Label或TextBox的DataTemplate。
修改
这是一些示例代码
<DataGridTemplateColumn x:Name="colB" Width="40*" IsReadOnly="True" >
<DataGridTemplateColumn.HeaderTemplate>
<DataTemplate>
<Label Content="Column B" ToolTip="A short explanation of Column B"/>
</DataTemplate>
</DataGridTemplateColumn.HeaderTemplate>
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock />
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
答案 1 :(得分：2)
我认为如果您只使用DataGridTemplateColumn.HeaderStyle代替DataGridTemplateColumn.Header
作为c栏的例子：
<DataGridTemplateColumn x:Name="colC" Width="40*" IsReadOnly="True" >
<DataGridTemplateColumn.HeaderStyle>
<Style TargetType="DataGridColumnHeader">
<Setter Property="ContentTemplate">
<Setter.Value>
<DataTemplate>
<TextBlock Text="Column C" ToolTip="A short explanation of Column C "/>
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
</DataGridTemplateColumn.HeaderStyle>
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock />
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>
</DataGridTemplateColumn.HeaderStyle>
答案 2 :(得分：0)
我喜欢 CodePlex 的列选择器解决方案： DataGrid Behavior
我清理了代码并删除了不必要的代码：
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Media;
using Microsoft.Xaml.Behaviors;
namespace Behaviors
{
public class WpfDataGridConfigurationBehavior : Behavior<DependencyObject>
{
#region "public Properties"
public bool DontPersistVisibleColumns { get; set; }
public bool DontPersistColumnsOrder { get; set; }
public string ContextMenuChoices { get; set; } = "Alphabetical Menu,Show All Columns";
public string DataGridName { get; set; }
#endregion "public Properties"
#region "private Properties"
private DataGrid dataGrid;
private ContextMenu theContextMenu; // Context Menu for the field chooser.
private string AllColumnsHeaders { get; set; }
private string AllColumnDisplayIndexes { get; set; }
private int nBaseItems = 5;
private MenuItem mnuAlpha;
private MenuItem mnuShowAll;
#endregion "Private Properties"
protected override void OnAttached()
{
base.OnAttached();
dataGrid = this.AssociatedObject as DataGrid;
if (DataGridName == null) DataGridName = dataGrid.Name;
ContextMenu_BuildStaticMenu();
dataGrid.Loaded += (sender, e) => { DataGrid_Loaded(); };
dataGrid.AutoGeneratedColumns += DataGrid_AutoGeneratedColumns;
dataGrid.ColumnReordered += (sender, e) => { DataGrid_ColumnReordered(sender); };
dataGrid.ContextMenuOpening += (sender, e) => { DataGrid_ContextMenuOpening(e); };
dataGrid.LoadingRow += (sender, e) => { e.Row.Header = (e.Row.GetIndex() + 1).ToString(); };
dataGrid.RowHeaderWidth = 0;
var ns = new Style(typeof(DataGridRowHeader)) { BasedOn = dataGrid.RowHeaderStyle };
ns.Setters.Add(new Setter(Control.FontWeightProperty, FontWeights.Bold));
ns.Setters.Add(new Setter(Control.FontSizeProperty, 11.0));
ns.Setters.Add(new Setter(Control.PaddingProperty, new Thickness(4, 0, 4, 0)));
dataGrid.RowHeaderStyle = ns;
}
private void DataGrid_AutoGeneratedColumns(object sender, EventArgs e)
{
DataGrid_Loaded();
}
#region "DataGrid Events"
private void DataGrid_ContextMenuOpening(ContextMenuEventArgs e)
{
var dep = (DependencyObject)e.OriginalSource;
// iteratively traverse the visual tree
while ((dep != null) && !(dep is DataGridCell) && !(dep is DataGridColumnHeader))
dep = VisualTreeHelper.GetParent(dep);
if (dep == null)
return;
if (dep is DataGridColumnHeader)
{
// do something
}
if (dep is DataGridCell)
{
// navigate further up the tree
while ((dep != null) && !(dep is DataGridRow))
dep = VisualTreeHelper.GetParent(dep);
var row = dep as DataGridRow;
dataGrid.ItemContainerGenerator.IndexFromContainer(row);
}
}
private void DataGrid_ColumnReordered(object sender)
{
Settings_SaveDisplayIndexes(sender);
ContextMenu_BuildMenu();
}
private void DataGrid_Loaded()
{
ContextMenu_BuildMenu(false);
VisibleColumns_Initialize();
}
#endregion "DataGrid Events"
#region "ContextMenu Methods and Events"
private void ContextMenu_BuildStaticMenu()
{
theContextMenu = new ContextMenu { FontSize = 11, StaysOpen = true };
mnuAlpha = new MenuItem
{
Header = ContextMenuChoices.Split(',')[0],
FontWeight = FontWeights.Bold,
IsCheckable = true,
StaysOpenOnClick = true
};
mnuAlpha.Click += (sender, e) => { ContextMenu_BuildMenu(); };
mnuShowAll = new MenuItem
{
Header = ContextMenuChoices.Split(',')[1],
FontWeight = FontWeights.Bold,
IsCheckable = true,
StaysOpenOnClick = true
};
mnuShowAll.Checked += (sender, e) => { VisibleColumns = AllColumnsHeaders; };
mnuShowAll.Click += (sender, e) =>
{
if (mnuShowAll.IsChecked == false) VisibleColumns_Initialize();
};
theContextMenu.Items.Add(mnuShowAll);
theContextMenu.Items.Add(mnuAlpha);
}
private void ContextMenu_BuildMenu(bool pbRebuild = true)
{
for (int i = theContextMenu.Items.Count - 1; i > 0; i--)
if (((MenuItem)theContextMenu.Items[i]).FontWeight != FontWeights.Bold)
theContextMenu.Items.Remove(theContextMenu.Items[i]);
nBaseItems = theContextMenu.Items.Count;
// Attach the context menu to the DataGrid ColumnHeaders
var headersPresenter = WpfDataGridConfigurationBehaviorFinder.FindChild<DataGridColumnHeadersPresenter>(dataGrid);
ContextMenuService.SetContextMenu(headersPresenter, theContextMenu);
if (VisibleColumns == null)
throw (new SettingsPropertyNotFoundException("User's VisibleColumns setting not found."));
// Get the current column ordering from user.config
if (DisplayIndexes == null)
throw (new SettingsPropertyNotFoundException("User's DisplayIndexes setting not found."));
AllColumnDisplayIndexes = DisplayIndexes;
string[] colIndexes = AllColumnDisplayIndexes.Split(new[] { ';' }, StringSplitOptions.RemoveEmptyEntries);
var dataGridColumns = dataGrid.Columns.OrderBy(x => x.DisplayIndex);
// Sort the columns in display index order so menu header order matchs display column order
if (pbRebuild == false)
// Initially the datagrid column order is such that display indexes are the same as the col indexes
if (colIndexes.Length > 0)
dataGridColumns = dataGrid.Columns.OrderBy(x => Convert.ToInt16(colIndexes[x.DisplayIndex]));
if (mnuAlpha.IsChecked)
dataGridColumns = dataGrid.Columns.OrderBy(x => x.Header.ToString());
AllColumnsHeaders = "";
foreach (var col in dataGridColumns)
{
// All column name to a list of all column headers for later use.
AllColumnsHeaders = $"{col.Header.ToString().Replace("\n", " ").Replace("\r", " ")};{AllColumnsHeaders}";
// Add new menu item in display order.
ContextMenu_AddNewMenuItem(col);
}
string sTemp = VisibleColumns;
VisibleColumns = null;
VisibleColumns = sTemp;
}
private void ContextMenu_AddNewMenuItem(DataGridColumn col)
{
var menuItem = new MenuItem { Header = col.Header.ToString().Replace("\n", " ").Replace("\r", " "), StaysOpenOnClick = true };
var saVisibleColumns = new List<string> { string.Empty };
if (VisibleColumns != null)
{
saVisibleColumns = VisibleColumns.Split(new[] { ';' }, StringSplitOptions.RemoveEmptyEntries).ToList();
}
menuItem.IsChecked = (saVisibleColumns.Contains(menuItem.Header));
menuItem.Click += (sender, e) => { ContextMenu_ColumnName_Click(sender); };
theContextMenu.Items.Add(menuItem);
}
private void ContextMenu_ColumnName_Click(object sender)
{
var mi = sender as MenuItem;
// Get the column name that was clicked
string colName = mi.Header.ToString();
// Capture new visible columns list
Settings_SaveVisibleColumns(mi, colName);
}
#endregion "ContextMenu Methods and Events"
#region "Settings Methods"
private void Settings_SaveVisibleColumns(MenuItem mi, string colName)
{
if (theContextMenu.Items.Count - nBaseItems < dataGrid.Columns.Count)
return;
// Put the visible column names into an array
var saVisibleColumns = VisibleColumns.Split(new char[] { ';' }, StringSplitOptions.RemoveEmptyEntries).ToList();
if (saVisibleColumns != null && saVisibleColumns.Count > 0 &&
saVisibleColumns[saVisibleColumns.Count - 1].StartsWith("-"))
saVisibleColumns.RemoveAt(saVisibleColumns.Count - 1);
// If the menu item is unchecked (column is not visible)
if (!mi.IsChecked)
// Make the column visible by adding its name to the Visible Columns list
saVisibleColumns.Add(colName);
else
// Hide the column by removing its name from the VisibleColumns list
if (saVisibleColumns.Contains(colName) && saVisibleColumns.Count > 1)
saVisibleColumns.Remove(colName);
VisibleColumns = string.Join(";", saVisibleColumns) + ";";
}
private void Settings_SaveDisplayIndexes(object sender)
{
// Capture the new column order
AllColumnDisplayIndexes = "";
foreach (DataGridColumn col in ((DataGrid)sender).Columns)
{
AllColumnDisplayIndexes +=
(AllColumnDisplayIndexes.Length > 0 ? ";" : "") + col.DisplayIndex;
}
DisplayIndexes = AllColumnDisplayIndexes;
}
#endregion "Settings Methods"
#region DisplayIndexes (DependencyProperty)
public string DisplayIndexes
{
get { return (string)GetValue(DisplayIndexesProperty); }
set { SetValue(DisplayIndexesProperty, value); }
}
public static readonly DependencyProperty DisplayIndexesProperty =
DependencyProperty.Register("DisplayIndexes", typeof(string), typeof(WpfDataGridConfigurationBehavior), new PropertyMetadata("", OnDisplayIndexesChanged));
private static void OnDisplayIndexesChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
((WpfDataGridConfigurationBehavior)d).DisplayIndexesChanged(e);
}
public void DisplayIndexesChanged(DependencyPropertyChangedEventArgs e)
{
// Persist the new column order
if (dataGrid != null && !DontPersistColumnsOrder)
Settings_Save(DataGridName + "DisplayIndexes", AllColumnDisplayIndexes);
}
#endregion "DisplayIndexes (DependencyProperty)"
#region VisibleColumns (DependencyProperty)
/// <summary>
///
/// Gets or sets a value indicating the names of columns
/// (as they appear in the column header) to be visible, seperated by a semicolon.
///
/// Columns whose names are not here will be hidden.
/// </summary>
public string VisibleColumns
{
get { return (string)GetValue(VisibleColumnsProperty); }
set { SetValue(VisibleColumnsProperty, value); }
}
private void VisibleColumns_Initialize()
{
// Get saved VisibleColumns from app.config
// Initialize VisibleColumns
VisibleColumns = string.IsNullOrEmpty(VisibleColumns.Replace("\n", " ").Replace("\r", " ")) ? AllColumnsHeaders : VisibleColumns;
}
public static readonly DependencyProperty VisibleColumnsProperty =
DependencyProperty.Register("VisibleColumns", typeof(string), typeof(WpfDataGridConfigurationBehavior), new PropertyMetadata("", OnVisibleColumnsChanged));
private static void OnVisibleColumnsChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
{
((WpfDataGridConfigurationBehavior)d).VisibleColumnsChanged(e);
}
/// <summary>
///
/// Updates the display
///
/// </summary>
/// <param name="e"></param>
public void VisibleColumnsChanged(DependencyPropertyChangedEventArgs e)
{
if (theContextMenu == null)
return;
if (e.NewValue != null)
{
var showTheseColumns = e.NewValue.ToString().Split(new[] { ';' }, StringSplitOptions.RemoveEmptyEntries);
var saContextMenuVisibleItems = new List<string>();
int iCol = 0;
foreach (MenuItem menuItem in theContextMenu.Items)
{
// Show/Hide the Context Menu item's checkmark.
if (menuItem.FontWeight == FontWeights.Bold) continue;
menuItem.IsChecked = showTheseColumns.Contains(menuItem.Header.ToString());
if (menuItem.IsChecked) saContextMenuVisibleItems.Add(menuItem.Header.ToString());
mnuShowAll.IsChecked = mnuShowAll.IsChecked && menuItem.IsChecked;
// Assign menu item's column's DisplayIndex in display order, (i.e. in menu item order), looking up each column by header name.)
if (mnuAlpha.IsChecked == false)
dataGrid.Columns.First(x => x.Header.ToString().Replace("\n", " ").Replace("\r", " ") == menuItem.Header.ToString()).DisplayIndex = iCol++;
}
// Show the columns
foreach (var col in dataGrid.Columns)
col.Visibility =
showTheseColumns.Contains(col.Header.ToString().Replace("\n", " ").Replace("\r", " "))
&& (saContextMenuVisibleItems.Contains(col.Header.ToString().Replace("\n", " ")
.Replace("\r", " ")))
? Visibility.Visible
: Visibility.Collapsed;
// Persist the new visible columns list
if (dataGrid != null && !DontPersistVisibleColumns)
Settings_Save(DataGridName + "VisibleColumns", VisibleColumns);
}
}
#endregion "VisibleColumns"
public static void Settings_Save(string propertyName, string propertyValue)
{
foreach (SettingsPropertyValue property in Settings.Default.PropertyValues)
{
if (propertyName == property.Name)
{
property.PropertyValue = propertyValue;
Settings.Default.Save();
}
}
}
}
public static class WpfDataGridConfigurationBehaviorFinder
{
public static T FindChild<T>(DependencyObject depObj) where T : DependencyObject
{
// Confirm obj is valid.
if (depObj == null) return null;
// success case
if (depObj is T) return depObj as T;
for (int i = 0; i < VisualTreeHelper.GetChildrenCount(depObj); i++)
{
T obj = FindChild<T>(VisualTreeHelper.GetChild(depObj, i));
if (obj != null) return obj;
}
return null;
}
public interface IBreakVisualParenting
{
DependencyObject Parent { get; }
}
public static T LastVisualAncestorOfType<T>(this DependencyObject element) where T : DependencyObject
{
T item = null;
var parent = VisualTreeHelper.GetParent(element);
while (parent != null)
{
if (parent is T)
item = (T)parent;
if (parent is IBreakVisualParenting)
{
parent = ((IBreakVisualParenting)parent).Parent;
}
else
parent = VisualTreeHelper.GetParent(parent);
}
return item;
}
}
}