在学习DataGrid的过程中，发现自定义DataGridColumnheader 会非常必要，而且可以自定以column 模板。

本例子主要是自定义了Column Header, 自定义Column 内容显示，可以对Column Header的排序和通过拖动header修改column的宽度.

1. 在xml 中添加如下资源

a. 带有箭头的datatemplate, 为用户点Header排序的时候可以显示不同的箭头

向上的箭头data template:                         

            <DataTemplate x:Key="ColumHeaderArrowUp"><DockPanel><TextBlock HorizontalAlignment="Center" VerticalAlignment="Center" Text="{Binding}"></TextBlock><Path x:Name="PT" Stroke="Gray" Fill="SeaGreen" RenderTransformOrigin="0.5,.5"><Path.RenderTransform><RotateTransform x:Name="RT" Angle="0"></RotateTransform></Path.RenderTransform><Path.Data><PathGeometry><PathFigure StartPoint="3.5,3"><LineSegment Point="0,9"></LineSegment><LineSegment Point="7,9"></LineSegment><LineSegment Point="3.5,3"></LineSegment></PathFigure></PathGeometry></Path.Data></Path></DockPanel></DataTemplate>

      向下的箭头 data template:

            <DataTemplate x:Key="ColumHeaderArrowDown"><DockPanel><TextBlock HorizontalAlignment="Center" VerticalAlignment="Center" Text="{Binding}"></TextBlock><Path x:Name="PT" Stroke="Gray" Fill="SeaGreen" RenderTransformOrigin="0.5,0.5"><Path.RenderTransform><RotateTransform x:Name="RT" Angle="180"></RotateTransform></Path.RenderTransform><Path.Data><PathGeometry><PathFigure StartPoint="3.5,3"><LineSegment Point="0,9"></LineSegment><LineSegment Point="7,9"></LineSegment><LineSegment Point="3.5,3"></LineSegment></PathFigure></PathGeometry></Path.Data></Path></DockPanel></DataTemplate>

b. 添加数据资源

                  首先为XML增加如下namespace:

             xmlns:Local="clr-namespace:ImageVideoPlayer"xmlns:sys="clr-namespace:System;assembly=mscorlib"xmlns:sysModel="clr-namespace:System.ComponentModel;assembly=System"

                  增加性别资源， 需要在.cs文件中增加类   public class GenderCollection:ObservableCollection<string>{}

            <Local:GenderCollection x:Key="gendercollection"><sys:String>Man</sys:String><sys:String>Female</sys:String></Local:GenderCollection>

  增加employee 信息， 在.cs文件中增加类    public class EmployeeCollection : ObservableCollection<Employee>{}

            <Local:EmployeeCollection x:Key="employeecollection"><Local:Employee FirstName="A1" LastName="Micheal" bValid="True" Gender="Man" Number="1"></Local:Employee><Local:Employee FirstName="A2" LastName="Micheal" bValid="True" Gender="Man" Number="2"></Local:Employee><Local:Employee FirstName="A3" LastName="Micheal" bValid="True" Gender="Female" Number="3"></Local:Employee><Local:Employee FirstName="A4" LastName="Micheal" bValid="True" Gender="Female" Number="4"></Local:Employee></Local:EmployeeCollection>

                   

c.添加header的style

            <Style TargetType="DataGridColumnHeader" BasedOn="{StaticResource {x:Type DataGridColumnHeader}}"><Setter Property="Template"><Setter.Value><ControlTemplate><Button Height="auto" Content="{Binding}" x:Name="Btn" Width="auto" Click="Btn_Click" MouseEnter="Btn_MouseEnter" MouseLeave="Btn_MouseLeave" MouseMove="Btn_MouseMove" PreviewMouseDown="Btn_PreviewMouseDown"></Button><ControlTemplate.Triggers><Trigger Property="DataGridColumnHeader.SortDirection" Value="0"><Setter Property="Button.ContentTemplate" TargetName="Btn" Value="{DynamicResource ColumHeaderArrowUp}"></Setter></Trigger><Trigger Property="DataGridColumnHeader.SortDirection" Value="1"><Setter Property="Button.ContentTemplate" TargetName="Btn" Value="{DynamicResource ColumHeaderArrowDown}"></Setter></Trigger></ControlTemplate.Triggers></ControlTemplate></Setter.Value></Setter><EventSetter Event="Click" Handler="HeaderClickRoutedEventHandler"></EventSetter><EventSetter Event="DragOver" Handler="HeaderDragOverEventHandler"></EventSetter><EventSetter Event="Drop" Handler="HeaderDragDropEventHandler"></EventSetter><EventSetter Event="PreviewMouseLeftButtonDown" Handler="HeaderMouseButtonEventHandler"></EventSetter></Style>

d. 添加DataGrid

        <DataGrid x:Name="EmployeeGrid" HorizontalAlignment="Left" Margin="0" VerticalAlignment="Top" ItemsSource="{StaticResource employeecollection}" AutoGenerateColumns="False" AlternationCount="2"MinColumnWidth="20" CanUserAddRows="False" CanUserResizeRows="False" CanUserSortColumns="True" SelectionUnit="FullRow" AllowDrop="True" SelectionMode="Single" CanUserReorderColumns="True" RowDetailsVisibilityMode="VisibleWhenSelected"><DataGrid.Columns><DataGridTextColumn Header="Number" Binding="{Binding Number}"></DataGridTextColumn><DataGridTextColumn Header="First Name" Binding="{Binding FirstName}"></DataGridTextColumn><DataGridTextColumn Header="Last Name" Binding="{Binding LastName}"></DataGridTextColumn><DataGridTemplateColumn Header="Gender" SortMemberPath="{Binding Gender}"><DataGridTemplateColumn.CellTemplate><DataTemplate><StackPanel><TextBlock Text="{Binding Gender}"></TextBlock></StackPanel></DataTemplate></DataGridTemplateColumn.CellTemplate><DataGridTemplateColumn.CellEditingTemplate><DataTemplate><StackPanel><ComboBox ItemsSource="{StaticResource gendercollection}" SelectedItem="{Binding Gender}"></ComboBox></StackPanel></DataTemplate></DataGridTemplateColumn.CellEditingTemplate></DataGridTemplateColumn><DataGridCheckBoxColumn Header="Valid" Binding="{Binding bValid}"></DataGridCheckBoxColumn></DataGrid.Columns></DataGrid>

2. 在.cs文件中内容

using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;namespace ImageVideoPlayer
{/// <summary>/// Interaction logic for GridDragDropManual.xaml/// </summary>public partial class GridDragDropManual : UserControl{public GridDragDropManual(){InitializeComponent();}#region helperpublic void SortColumn(string header, bool bAescending){var employees = this.grid.Resources["employeecollection"] as EmployeeCollection;var tempList = new List<Employee>();tempList.AddRange(employees);tempList.Sort((x, y) =>{var tempX = x;var tempY = y;if(bAescending){tempX = y;tempY = x;}if (header.Contains("First"))return tempX.FirstName.CompareTo(tempY.FirstName);else if (header.Contains("Last"))return tempX.LastName.CompareTo(tempY.LastName);else if (header.Contains("Number"))return tempX.Number.CompareTo(tempY.Number);else if (header.Contains("Gender"))return tempX.Gender.CompareTo(tempY.Gender);else if(header.Contains("Valid"))return tempX.bValid.CompareTo(tempY.bValid);return 0;});employees.Clear();foreach(var tmp in tempList){employees.Add(tmp);}}void ClearSort(){foreach (var clm in this.EmployeeGrid.Columns){//clm.HeaderTemplate = null;clm.SortDirection = null;}}#endregion#region eventpublic static readonly DependencyProperty DPbUp = DependencyProperty.Register("bUp", typeof(bool), typeof(GridDragDropManual));bool _bUp = true;bool bUp { get { return (bool)GetValue(DPbUp); } set { SetValue(DPbUp,value); } }bool bColumnResize = false;int ResizeIndex;void HeaderClickRoutedEventHandler(object sender, System.Windows.RoutedEventArgs e){if (bColumnResize) return;var header = sender as DataGridColumnHeader;if (header == null) return;            SortColumn(header.Content as string, bUp);bUp = !bUp;_bUp = bUp;ClearSort();header.Column.SortDirection = bUp ? ListSortDirection.Ascending : ListSortDirection.Descending;this.EmployeeGrid.CurrentColumn = header.Column;}private void HeaderDragOverEventHandler(object sender, System.Windows.DragEventArgs e){}private void HeaderDragDropEventHandler(object sender, System.Windows.DragEventArgs e){}private void HeaderMouseButtonEventHandler(object sender, System.Windows.Input.MouseButtonEventArgs e){}#endregionprivate void Btn_Click(object sender, RoutedEventArgs e){}private void Btn_MouseEnter(object sender, MouseEventArgs e){}private void Btn_MouseLeave(object sender, MouseEventArgs e){if (bColumnResize){Cursor = Cursors.Arrow;bColumnResize = false;}}Point oldPos;private void Btn_MouseMove(object sender, MouseEventArgs e){var btn = sender as Button;if (btn == null) return;var pos = e.GetPosition(btn);var rect = VisualTreeHelper.GetDescendantBounds(btn);var parent = VisualTreeHelper.GetParent(btn);while(parent != null){if(parent is DataGridColumnHeader){break;}parent = VisualTreeHelper.GetParent(parent);}if(parent == null)return;var header = parent as DataGridColumnHeader;            if (e.LeftButton == MouseButtonState.Pressed){if (bColumnResize && header.Column.DisplayIndex == ResizeIndex){header.Column.Width = new DataGridLength(header.Column.ActualWidth + pos.X - oldPos.X);oldPos = pos;}elsebColumnResize = false;}else{oldPos = pos;rect.Inflate(0, -3);bool bDragArea = false;if (rect.Contains(pos)){if ((rect.Right - pos.X) < 10){bDragArea = true;}}if (bDragArea){Cursor = Cursors.SizeWE;if (!bColumnResize){bColumnResize = true;ResizeIndex = header.Column.DisplayIndex;}}elsebColumnResize = false;}if (!bColumnResize){Cursor = Cursors.Arrow;ResizeIndex = -1;}}private void Btn_PreviewMouseDown(object sender, MouseButtonEventArgs e){if (bColumnResize)e.Handled = true;if(bColumnResize){var btn = sender as Button;oldPos = e.GetPosition(btn);}}}public class GenderCollection:ObservableCollection<string>{}public class EmployeeCollection : ObservableCollection<Employee>{}public class Employee{public string FirstName { get; set; }public string LastName { get; set; }public int Number { get; set; }public string Gender { get; set; }public bool bValid { get; set; }public Employee(){bValid = true;Gender = "Man";}}