WPF DataGrid开箱即用支持全部勾选的DataGridCheckBoxColumn

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所属分类:.NET技术
摘要

以往在WPF的DataGrid上实现实时勾选交互非常麻烦,要用DataGridTemplateColumn写样式还要写一些后端代码,还有绑定和转换器,或者处理事件。

本文由 飞羽流星(Flithor/毛茸茸松鼠先生/Mr.Squirrel.Downy)原创,欢迎分享转载,但禁止以原创二次发布
原文地址:https://www.cnblogs.com/Flithor/p/17877473.html

以往在WPF的DataGrid上实现实时勾选交互非常麻烦,要用DataGridTemplateColumn写样式还要写一些后端代码,还有绑定和转换器,或者处理事件。

但是现在都不需要了,使用开箱即用的DataGridCheckAllColumn,简化你的勾选代码实现!

它支持列表筛选变化反馈,支持虚拟化,支持单项勾选变化的更新反馈。

效果预览:

WPF DataGrid开箱即用支持全部勾选的DataGridCheckBoxColumn

而且非常简单好用

<DataGrid.Columns>     <!-- 像使用DataGridCheckBoxColumn那样使用和绑定就行 -->     <fc:DataGridCheckAllColumn Binding="{Binding IsChecked}" />     <!-- 其它列 -->     <DataGridTextColumn Binding="{Binding EntityName}" /> </DataGrid.Columns>

注意! 如果你在DataGrid上设置了VirtualizingPanel.IsVirtualizing="True"应用虚拟化 需要同时设置VirtualizingPanel.VirtualizationMode="Standard",避免出现绑定实例错误的Bug

DataGridCheckAllColumn类的实现:

// 代码作者: 飞羽流星(Flithor/Mr.Squirrel.Downy/毛茸茸松鼠先生) // 开源许可: MIT // =======警告======= // 使用开源代码的风险自负  using System; using System.Collections.Generic; using System.ComponentModel; using System.Globalization; using System.Linq; using System.Reflection; using System.Runtime.Remoting.Messaging; using System.Windows; using System.Windows.Controls; using System.Windows.Controls.Primitives; using System.Windows.Data; using System.Windows.Media;  using Expression = System.Linq.Expressions.Expression;  namespace Flithor_Codes {     /// <summary>     /// 一个支持勾选所有的DataGrid列     /// </summary>     public class DataGridCheckAllColumn : DataGridBoundColumn     {         #region 私有字段         //列头中的CheckBox         private readonly CheckBox checkAllCheckBox;         //所属DataGrid控件         private DataGrid ownerDatagrid;        //所属DataGrid控件的列表版本,如果版本号改变则说明列表改变         private Func<int> getInnerEnumeratorVersion;         //缓存的列表版本号         private int cachedInnerVersion;         //CheckBox的默认样式         private static Style _defaultElementStyle;         #endregion          #region 初始化控件         public static Style DefaultElementStyle         {             get             {                 if (_defaultElementStyle == null)                 {                     var style = new Style(typeof(CheckBox))                     {                         Setters =                         {                             new Setter(UIElement.FocusableProperty, false),                             new Setter(CheckBox.HorizontalAlignmentProperty, HorizontalAlignment.Center),                             new Setter(CheckBox.VerticalAlignmentProperty, VerticalAlignment.Center)                         }                     };                      style.Seal();                     _defaultElementStyle = style;                 }                  return _defaultElementStyle;             }         }          static DataGridCheckAllColumn()         {             //重写单元格元素默认样式             ElementStyleProperty.OverrideMetadata(typeof(DataGridCheckAllColumn), new FrameworkPropertyMetadata(DefaultElementStyle));             //使列默认只读             IsReadOnlyProperty.OverrideMetadata(typeof(DataGridCheckAllColumn), new FrameworkPropertyMetadata(true));             //不允许重排此列             CanUserReorderProperty.OverrideMetadata(typeof(DataGridCheckAllColumn), new FrameworkPropertyMetadata(false));             //不允许修改此列宽度             CanUserResizeProperty.OverrideMetadata(typeof(DataGridCheckAllColumn), new FrameworkPropertyMetadata(false));             //不允许点击列头排序项目             CanUserSortProperty.OverrideMetadata(typeof(DataGridCheckAllColumn), new FrameworkPropertyMetadata(false));         }          public DataGridCheckAllColumn()         {             //设置列头             Header = checkAllCheckBox = new CheckBox();         }          protected override void OnPropertyChanged(DependencyPropertyChangedEventArgs e)         {             if (ownerDatagrid != null) return;              ownerDatagrid = GetParentDataGrid();             if (ownerDatagrid == null) return;              InitInnerVersionDetect(ownerDatagrid.Items);              ((INotifyPropertyChanged)ownerDatagrid.Items).PropertyChanged += OnPropertyChanged;              //如果DataGrid当前已有项目,则初始化绑定             checkAllCheckBox.IsEnabled = ownerDatagrid.Items.Count > 0;             if (checkAllCheckBox.IsEnabled)                 ResetCheckCurrentAllBinding();         }         //寻找所属DataGrid控件(如果还没初始化完毕,可能返回空值)         private DataGrid GetParentDataGrid()         {             DependencyObject elment = checkAllCheckBox;             do             {                 elment = VisualTreeHelper.GetParent(elment);             }             while (elment != null && !(elment is DataGrid));             return elment as DataGrid;         }         #endregion          #region 构建单元格元素(方法的功能不言自明)         protected override FrameworkElement GenerateElement(DataGridCell cell, object dataItem)         {             return GenerateCheckBox(false, cell, dataItem);         }          protected override FrameworkElement GenerateEditingElement(DataGridCell cell, object dataItem)         {             return GenerateCheckBox(true, cell, dataItem);         }          private CheckBox GenerateCheckBox(bool isEditing, DataGridCell cell, object dataItem)         {             var checkBox = new CheckBox();             ApplyStyle(isEditing, checkBox);             ApplyBinding(dataItem, checkBox);             return checkBox;         }          private void ApplyBinding(object dataItem, CheckBox checkBox)         {             var binding = CloneBinding(Binding, dataItem);             if (binding is Binding newBinding)             {                 newBinding.Mode = BindingMode.TwoWay;                 newBinding.UpdateSourceTrigger = UpdateSourceTrigger.PropertyChanged;             }             BindingOperations.ClearBinding(checkBox, CheckBox.IsCheckedProperty);             checkBox.SetBinding(CheckBox.IsCheckedProperty, binding);         }          internal void ApplyStyle(bool isEditing, FrameworkElement element)         {             Style style = PickStyle(isEditing);             if (style != null)             {                 element.Style = style;             }         }          private Style PickStyle(bool isEditing)         {             Style style = isEditing ? EditingElementStyle : ElementStyle;             if (isEditing && (style == null))             {                 style = ElementStyle;             }              return style;         }         #endregion          #region 更新绑定         private void OnPropertyChanged(object sender, PropertyChangedEventArgs e)         {             if (ownerDatagrid == null || e.PropertyName != nameof(ownerDatagrid.Items.Count))                 return;             //如果项目数量发生改变意味着列表更新了             if (ownerDatagrid.Items.Count == 0)             {                 //如果列表空了,那就移除绑定并禁用列头勾选控件                 BindingOperations.ClearBinding(checkAllCheckBox, CheckBox.IsCheckedProperty);                 checkAllCheckBox.IsEnabled = false;             }             else             {                 //否则基于当前列表显示项更新绑定                 ResetCheckCurrentAllBinding();                 checkAllCheckBox.IsEnabled = true;             }         }          private void ResetCheckCurrentAllBinding()         {             //如果列表版本号改变则更新,否则无需更新             if (ownerDatagrid == null || !InnerVersionChanged()) return;              var checkAllBinding = new MultiBinding             {                 Converter = AllBoolStatusConverter.Default,                 Mode = BindingMode.TwoWay             };             //基于所有列表显示项创建绑定             var currentItems = ownerDatagrid.Items.OfType<object>().ToList();             foreach (var item in currentItems)             {                 checkAllBinding.Bindings.Add(CloneBinding((Binding)Binding, item));             }              //清除旧绑定             BindingOperations.ClearBinding(checkAllCheckBox, CheckBox.IsCheckedProperty);              checkAllCheckBox.SetBinding(CheckBox.IsCheckedProperty, checkAllBinding);         }          //创建获取内部列表版本号的委托         private void InitInnerVersionDetect(ItemCollection itemCollection)         {             //Timestamp属性是内部列表的版本号标识,用于表示列表变更的次数             var collectionTimestampProerty = itemCollection.GetType()                 .GetProperty("Timestamp", BindingFlags.Instance | BindingFlags.NonPublic);             //使用Linq的Expression来构建访问Timestamp属性的委托方法             getInnerEnumeratorVersion = Expression.Lambda<Func<int>>(Expression.Property(                 Expression.Constant(itemCollection),                 collectionTimestampProerty)).Compile();         }         //检查内部列表是否发生了更新         private bool InnerVersionChanged()         {             var currentInnerVersion = getInnerEnumeratorVersion.Invoke();             if (currentInnerVersion != cachedInnerVersion)             {                 cachedInnerVersion = currentInnerVersion;                 return true;             }              return false;         }         //基于已有绑定对象创建一个副本,使用指定的数据源         private static BindingBase CloneBinding(BindingBase bindingBase, object source)         {             switch (bindingBase)             {                 case Binding binding:                     var resultBinding = new Binding                     {                         Source = source,                         AsyncState = binding.AsyncState,                         BindingGroupName = binding.BindingGroupName,                         BindsDirectlyToSource = binding.BindsDirectlyToSource,                         Converter = binding.Converter,                         ConverterCulture = binding.ConverterCulture,                         ConverterParameter = binding.ConverterParameter,                         //ElementName = binding.ElementName,                         FallbackValue = binding.FallbackValue,                         IsAsync = binding.IsAsync,                         Mode = binding.Mode,                         NotifyOnSourceUpdated = binding.NotifyOnSourceUpdated,                         NotifyOnTargetUpdated = binding.NotifyOnTargetUpdated,                         NotifyOnValidationError = binding.NotifyOnValidationError,                         Path = binding.Path,                         //RelativeSource = binding.RelativeSource,                         StringFormat = binding.StringFormat,                         TargetNullValue = binding.TargetNullValue,                         UpdateSourceExceptionFilter = binding.UpdateSourceExceptionFilter,                         UpdateSourceTrigger = binding.UpdateSourceTrigger,                         ValidatesOnDataErrors = binding.ValidatesOnDataErrors,                         ValidatesOnExceptions = binding.ValidatesOnExceptions,                         XPath = binding.XPath,                     };                      foreach (var validationRule in binding.ValidationRules)                     {                         resultBinding.ValidationRules.Add(validationRule);                     }                      return resultBinding;                 case MultiBinding multiBinding:                     var resultMultiBinding = new MultiBinding                     {                         BindingGroupName = multiBinding.BindingGroupName,                         Converter = multiBinding.Converter,                         ConverterCulture = multiBinding.ConverterCulture,                         ConverterParameter = multiBinding.ConverterParameter,                         FallbackValue = multiBinding.FallbackValue,                         Mode = multiBinding.Mode,                         NotifyOnSourceUpdated = multiBinding.NotifyOnSourceUpdated,                         NotifyOnTargetUpdated = multiBinding.NotifyOnTargetUpdated,                         NotifyOnValidationError = multiBinding.NotifyOnValidationError,                         StringFormat = multiBinding.StringFormat,                         TargetNullValue = multiBinding.TargetNullValue,                         UpdateSourceExceptionFilter = multiBinding.UpdateSourceExceptionFilter,                         UpdateSourceTrigger = multiBinding.UpdateSourceTrigger,                         ValidatesOnDataErrors = multiBinding.ValidatesOnDataErrors,                         ValidatesOnExceptions = multiBinding.ValidatesOnDataErrors,                     };                      foreach (var validationRule in multiBinding.ValidationRules)                     {                         resultMultiBinding.ValidationRules.Add(validationRule);                     }                      foreach (var childBinding in multiBinding.Bindings)                     {                         resultMultiBinding.Bindings.Add(CloneBinding(childBinding, source));                     }                      return resultMultiBinding;                 case PriorityBinding priorityBinding:                     var resultPriorityBinding = new PriorityBinding                     {                         BindingGroupName = priorityBinding.BindingGroupName,                         FallbackValue = priorityBinding.FallbackValue,                         StringFormat = priorityBinding.StringFormat,                         TargetNullValue = priorityBinding.TargetNullValue,                     };                      foreach (var childBinding in priorityBinding.Bindings)                     {                         resultPriorityBinding.Bindings.Add(CloneBinding(childBinding, source));                     }                      return resultPriorityBinding;                 default:                     throw new NotSupportedException("Failed to clone binding");             }         }         /// <summary>         /// 用于合并所有bool值到一个值的多值转换器         /// </summary>         private class AllBoolStatusConverter : IMultiValueConverter         {             public static readonly AllBoolStatusConverter Default = new AllBoolStatusConverter();              public object Convert(object[] values, Type targetType, object parameter, CultureInfo culture)             {                 if (values.Length == 0 || values.OfType<bool>().Count() != values.Length)                     return false;                 // 检查所有项是否和第一项相同                 var firstStatus = values.First();                  foreach (var value in values)                 {                     //如果有不同就返回null,表示第三态                     if (!Equals(value, firstStatus))                         return null;                 }                  return firstStatus;             }              public object[] ConvertBack(object value, Type[] targetTypes, object parameter, CultureInfo culture)             {                 //如果汇总的值发生变化则更新所有项目                 var res = new object[targetTypes.Length];                 for (int i = 0; i < res.Length; i++)                     res[i] = value;                 return res;             }         }         #endregion     } }

<<这是一条标识脚本盗传狗的隐形水印>>

<<本文由 飞羽流星(Flithor/毛茸茸松鼠先生/Mr.Squirrel.Downy)原创,欢迎分享转载,但禁止以原创二次发布>>