C# WPF DataGrid 内容绑定时的单元格编辑类型模板

DataGrid的DataSource绑定的ObservableCollection<UserType>属性如果在运行中会发生变动，则不能在xaml手动定义Columns，否则当该属性发生变动时，UI不会随之更新，需要使用以下方法来实现单元格编辑类型的替换：

一、

设置DataGrid的AutoGenerateColumns为True，自动生成列的同时在AutoGeneratingColumn事件的方法将e.Column属性替换为DataGridTemplateColumn实例。

xaml:

cs:

      private void DataGridAutoGeneratingColumn(object sender, DataGridAutoGeneratingColumnEventArgs e){DataGrid dataGrid = sender as DataGrid;string columnName = e.PropertyName;DataGridTemplateColumn column = new DataGridTemplateColumn();e.Column = column;}

在定义的DataGridTemplateColumn实例的CellTemplate和CellEditingTemplate属性赋值新的DataTemplate实例， 创建FrameworkElementFactory实例给DataTemplate实例的VisualTree赋值；FrameworkElementFactory实例可以使用SetBinding方法绑定数据源，使用SetValue方法指定模板，模板可定义在App.xaml里，通过Application.Current.FindResource方法获取。

 DataGridTemplateColumn column = new DataGridTemplateColumn();DgvCellDataTemplateSelector cellTemplate = Application.Current.FindResource("DgvCellTemplateSelector") as DgvCellDataTemplateSelector;DgvCellDataTemplateSelector cellEditingTemplate = Application.Current.FindResource("DgvCellEditingTemplateSelector") as DgvCellDataTemplateSelector;column.Header = columnName;column.CellTemplate = new DataTemplate();FrameworkElementFactory factory = new FrameworkElementFactory(typeof(ContentPresenter));factory.SetBinding(ContentPresenter.ContentProperty, new Binding(columnName));factory.SetValue(ContentPresenter.ContentTemplateSelectorProperty, cellTemplate);column.CellTemplate.VisualTree = factory;column.CellEditingTemplate = new DataTemplate();FrameworkElementFactory editingfactory = new FrameworkElementFactory(typeof(ContentPresenter));editingfactory.SetBinding(ContentPresenter.ContentProperty, new Binding(columnName));editingfactory.SetValue(ContentPresenter.ContentTemplateSelectorProperty, cellEditingTemplate);column.CellEditingTemplate.VisualTree = editingfactory;

二、

编写模板选择器，DgvCellDataTemplateSelector是个实现了DataTemplateSelector接口的类型：

public class TemplateMapping : List
{
}
public class TemplateMappingItem
{public object Value { get; set; }public DataTemplate Template { get; set; }
}
public class DgvCellDataTemplateSelector : DataTemplateSelector
{public DataTemplate DefaultTemplate { get; set; }public TemplateMapping TemplateMap { get; set; }public override DataTemplate SelectTemplate(object item, DependencyObject container){if (item == null) return DefaultTemplate;if (item is DataBase data){if (data == null) return DefaultTemplate;return TemplateMap?.Find(m => Equals(m.Value, data.dataType))?.Template ?? DefaultTemplate;}return DefaultTemplate;}
}

三、

定义模板和创建全局模板选择器实例，app.xaml:

四、

创建存放数据的UserType。

  public enum DataType{Readonly}public abstract class DataBase : NotifyPropertyChanged,ICloneable{private object value;public DataType dataType;public object Value { get { return value; } set { this.value = value;OnPropertyChanged(nameof(Value)); } }public DataBase() { }public abstract object Clone();}public class ReadOnlyData : DataBase{public ReadOnlyData(){dataType = DataType.Readonly;}public override object Clone(){var clone = new ReadOnlyData{Value = this.Value};return clone;}}