问题描述
看起来 WFP DataGridComboBoxColumn 正在为此列中的所有单元格使用单个 ItemsSource.我有一个案例，其中 ComboBox 项目依赖于同一行中的另一个单元格.我设法在 PreparingCellForEdit 事件中填充了 ItemsSource.但是，它不能按预期工作.最初，此列中的所有单元格都是空的.为该列的 ComboBox 填充 ItemsSource 后，所有相关单元格(具有相同项目源)都将显示值.但是，如果我单击另一种类型的单元格(填充了不同的项目源)，所有值都会消失，新类型的单元格会显示值.您只能为一列使用一组项目源吗?我不敢相信这是真的.我错过了什么吗?有什么解决方法吗?
It looks WFP DataGridComboBoxColumn is using a single ItemsSource for all cells in this column. I have a case where the ComboBox items are dependent on the other cell in the same row. I managed to populate the ItemsSource in PreparingCellForEdit event. However, it doesn't work as desired. Initially, all cells in this column is empty. Once I populate the ItemsSource for this column's ComboBox, all related cells (with the same items source) are showing values. However, if I click another type of cell (a different items source is populated), all values disappear and the new type cells show values. You can only use one set of Items Source for a column? I can't believe it is true. Did I miss anything? Any workaround?
推荐答案
感谢 Jonathan 的例子，我解决了我的问题如下.我修改了 Jonathan 的代码以突出显示我的解决方案.我从他的示例中删除了 Territory 属性，因为我的问题不需要它.
Thanks to Jonathan's example, I resolved my problem as follows. I modifiedy Jonathan's code to highlight my solution. I removed the Territory property from his example because I don't need it for my problem.
有两列.第一列是状态.第二列是StateCandidate.State 列绑定到 States 列表，StateCandidate 列绑定到 StateCandidates 列表.关键是 StateCandidates 列表会在 State 更改时重新创建.因此，每行中可能有不同的 StateCandidates 列表(基于所选的州).
There are two columns. First column is State. Second column is StateCandidate. State column is bind to a States list, and StateCandidate column is bind to a StateCandidates list. The key point is that the StateCandidates list is recreated when State is changed. So, there could be a different list of StateCandidates in each row (based on the selected State).
主窗口.xaml
<Window x:Class="WpfTest1.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>
<DataGrid Name="Zoom" AutoGenerateColumns="False" Background="DarkGray" RowHeaderWidth="50" HeadersVisibility="All">
<DataGrid.Columns>
<DataGridTemplateColumn x:Name="colState" Header="State" Width="120">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding State}" />
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
<DataGridTemplateColumn.CellEditingTemplate>
<DataTemplate>
<ComboBox SelectedItem="{Binding State}" ItemsSource="{Binding States}" />
</DataTemplate>
</DataGridTemplateColumn.CellEditingTemplate>
</DataGridTemplateColumn>
<DataGridTemplateColumn x:Name="colStateCandiate" Header="State Candidate" Width="200">
<DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding StateCandidate}" />
</DataTemplate>
</DataGridTemplateColumn.CellTemplate>
<DataGridTemplateColumn.CellEditingTemplate>
<DataTemplate>
<ComboBox SelectedItem="{Binding StateCandidate}" ItemsSource="{Binding StateCandidates}" />
</DataTemplate>
</DataGridTemplateColumn.CellEditingTemplate>
</DataGridTemplateColumn>
</DataGrid.Columns>
</DataGrid>
</Grid>
</Window>
MainWindow.xaml.cs
MainWindow.xaml.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
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;
using System.ComponentModel;
namespace WpfTest1
{
/// <summary>
/// Interaction logic for MainWindow.xaml
/// </summary>
public partial class MainWindow : Window
{
public MainWindow()
{
InitializeComponent();
List<Model> list = new List<Model>();
list.Add(new Model() { State = "TX", StateCandidate = "TX2" });
list.Add(new Model() { State = "CA" });
list.Add(new Model() { State = "NY", StateCandidate = "NY1" });
list.Add(new Model() { State = "TX" });
list.Add(new Model() { State = "AK" });
list.Add(new Model() { State = "MN" });
Zoom.ItemsSource = list;
Zoom.PreparingCellForEdit += new EventHandler<DataGridPreparingCellForEditEventArgs>(Zoom_PreparingCellForEdit);
}
void Zoom_PreparingCellForEdit(object sender, DataGridPreparingCellForEditEventArgs e)
{
if (e.Column == colStateCandiate)
{
DataGridCell cell = e.Column.GetCellContent(e.Row).Parent as DataGridCell;
cell.IsEnabled = (e.Row.Item as Model).StateCandidates != null;
}
}
}
public class Model : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
private string _state;
private List<string> _states = new List<string>() { "CA", "TX", "NY", "IL", "MN", "AK" };
private string _stateCandidate;
private List<string> _stateCandidates;
public string State
{
get { return _state; }
set
{
if (_state != value)
{
_state = value;
_stateCandidate = null;
if (_state == "CA" || _state == "TX" || _state == "NY")
_stateCandidates = new List<string> { _state + "1", _state + "2" };
else
_stateCandidates = null;
OnPropertyChanged("State");
}
}
}
public List<string> States
{
get { return _states; }
}
public string StateCandidate
{
get { return _stateCandidate; }
set
{
if (_stateCandidate != value)
{
_stateCandidate = value;
OnPropertyChanged("StateCandidate");
}
}
}
public List<string> StateCandidates
{
get { return _stateCandidates; }
}
public void OnPropertyChanged(string name)
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(name));
}
}
}
请注意，当 State 更改时，它不会更新 StateCandidates 列表，直到选择了不同的行，这是我将要解决的一个单独问题.有人知道我如何强制提交吗?
Note that, when State is changed, it won't update StateCandidates list until a different row is selected, which is a separated issue I'll be fighting. Do anybody know how I can force commit?
再次感谢乔纳森的灵感.我会继续寻找更好的解决方案.
Thanks to Jonathan again for his inspiration. I'll keep looking for a better solution.
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