对包含不同类型单元格的DataGrid列进行排序会引发ArgumentException

本文关键字:排序 ArgumentException 同类型 包含不 单元格 DataGrid | 更新日期: 2023-09-27 17:59:58

我有一个数据网格绑定到一个项目集合,该集合有一个类型为object的字段,该字段可以包含任何内容。。。布尔,字符串或任何东西。但是,当我单击列标题进行排序时,会抛出ArgumentException。我的意思是,这完全有道理,但我该如何避免这个问题。我只想将所有内容转换为字符串,并将它们作为字符串进行比较。使用转换器没有帮助。我无法更改ViewModel以对项的属性执行ToString,因此我需要一个仅视图的解决方案。

以下是一些示例代码:

XAML:

    <DataGrid
            ItemsSource="{Binding items}" 
            AutoGenerateColumns="False"  
            IsManipulationEnabled="False">
        <DataGrid.Columns>
            <DataGridTextColumn 
                    Header="Name"
                    IsReadOnly="True" 
                    Binding="{Binding Name}" />
            <DataGridTextColumn
                    Header="Content"              
                    IsReadOnly="True"
                    Binding="{Binding data, Converter={StaticResource toString}}"/>
        </DataGrid.Columns>
    </DataGrid>

C#:

public class MainViewModel : DependencyObject, INotifyPropertyChanged
{
    public MainViewModel()
    {
        items = new ObservableCollection<OneItem>();
        items.Add(new OneItem { Name = "Tom", Height = 180, Weight = 75, Class = 2, data = false });
        items.Add(new OneItem { Name = "Dick", Height = 182, Weight = 83, Class = 3, data = true });
        items.Add(new OneItem { Name = "Harry", Height = 182, Weight = 83, Class = 3, data = "Sting" });
    }
    public ObservableCollection<OneItem> items { get; private set; }
    public event PropertyChangedEventHandler PropertyChanged;
}
public class OneItem
{
    public string Name { get; set; }
    public double Height { get; set; }
    public double Weight { get; set; }
    public double Class { get; set; }
    public object data { get; set; }
}

例外:

System.Windows.Data Error: 55 : Cannot sort by 'data' InvalidOperationException:'System.InvalidOperationException: Failed to compare two elements in the array. ---> System.ArgumentException: Object must be of type Boolean.
   at System.Boolean.CompareTo(Object obj)
   at System.Collections.Comparer.Compare(Object a, Object b)
   at MS.Internal.Data.SortFieldComparer.Compare(Object o1, Object o2)
   at System.Array.SorterGenericArray.SwapIfGreaterWithItems(Int32 a, Int32 b)
   at System.Array.SorterGenericArray.IntroSort(Int32 lo, Int32 hi, Int32 depthLimit)
   at System.Array.SorterGenericArray.IntrospectiveSort(Int32 left, Int32 length)
   --- End of inner exception stack trace ---
   at System.Array.SorterGenericArray.IntrospectiveSort(Int32 left, Int32 length)
   at System.Array.Sort(Array keys, Array items, Int32 index, Int32 length, IComparer comparer)
   at System.Array.Sort(Array array, IComparer comparer)
   at MS.Internal.Data.SortFieldComparer.SortHelper(ArrayList al, IComparer comparer)
   at MS.Internal.Data.DataExtensionMethods.Sort(IList list, IComparer comparer)
   at System.Windows.Data.ListCollectionView.PrepareLocalArray()
   at System.Windows.Data.ListCollectionView.RefreshOverride()
   at System.Windows.Data.CollectionView.RefreshInternal()
   at System.Windows.Data.CollectionView.Refresh()
   at System.Windows.Data.CollectionView.EndDefer()
   at System.Windows.Data.CollectionView.DeferHelper.Dispose()
   at System.Windows.Controls.ItemCollection.EndDefer()
   at System.Windows.Controls.ItemCollection.DeferHelper.Dispose()
   at System.Windows.Controls.DataGrid.DefaultSort(DataGridColumn column, Boolean clearExistingSortDescriptions)'

对包含不同类型单元格的DataGrid列进行排序会引发ArgumentException

我添加这样的DataDisplay属性:

public class OneItem
{
    public string Name { get; set; }
    public double Height { get; set; }
    public double Weight { get; set; }
    public double Class { get; set; }
    public object data { get; set; }
    public object DataDisplay
    {
        get
        {
            if (data == null)
            {
                return string.Empty;
            }
            return data.ToString();
        }
    }
}

然后用DataDisplay替换数据,并删除绑定中的转换器:

<Grid>
    <DataGrid
        ItemsSource="{Binding items}" 
        AutoGenerateColumns="False"  
        IsManipulationEnabled="False">
        <DataGrid.Columns>
            <DataGridTextColumn 
                Header="Name"
                IsReadOnly="True" 
                Binding="{Binding Name}" />
            <DataGridTextColumn
                Header="Content"              
                IsReadOnly="True"
                Binding="{Binding DataDisplay}"/>
        </DataGrid.Columns>
    </DataGrid>
</Grid>

如果您还想要Converter。让我知道:)

最简单的方法是简单地添加(直接添加,或者通过扩展、继承或包装OneItem)一个只返回data.ToString()的计算属性,并将DataGridColumn绑定到该属性。你也可以避免使用转换器。

但另一种方法可能是实现DataGrid的自定义排序。

根据这里的指示,您可以创建附加的属性,以允许按列进行自定义排序,然后只需要为您的列创建一个ICustomSorter。在这种情况下,ICustomSorter将非常简单:

public class ObjectSorter : ICustomSorter
{
    public System.ComponentModel.ListSortDirection SortDirection { get; set; }
    public int Compare(object x, object y)
    {
        return x.ToString().CompareTo(y.ToString());
    }
}

然后在视图Resources中声明一个,并使用该链接中描述的附加属性将其设置到列中。

<DataGrid ItemsSource="{Binding items}" 
          AutoGenerateColumns="False"  
          IsManipulationEnabled="False"
          behaviours:CustomSortBehaviour.AllowCustomSort="True">
    <DataGrid.Resources>
        <sort:ObjectSorter x:Key="MyObjectSorter" />
    </DataGrid.Resources>
    <DataGrid.Columns>
        <DataGridTextColumn 
                Header="Name"
                IsReadOnly="True" 
                Binding="{Binding Name}" />
        <DataGridTextColumn
                Header="Content"              
                IsReadOnly="True"
                Binding="{Binding data, Converter={StaticResource toString}}"
                behaviours:CustomSortBehaviour.CustomSorter="{StaticResource MyObjectComparer}" />
    </DataGrid.Columns>
</DataGrid>