1

在此处输入图像描述这是我在此的头一篇博文。

我遇到的问题与DataGrid(WPF)中的复选框有关。抱歉,由于我是新用户,因此无法附上屏幕截图以便更好地理解问题。

问题:即使其中一个子项未选中,也会选中 DataHeader 列复选框。我希望解决方案能够解决此问题,以便当用户明确取消选中其中一个孩子时,应该隐式取消选中 ALL(Header)。

请帮助大家...谢谢!

请检查链接。我希望解决方案像这样工作。http://www.codeproject.com/Articles/42437/Toggling-the-States-of-all-CheckBoxes-Inside-a-Dat#

4

2 回答 2

1

我建议您有一个绑定到视图模型的视图。在我的代码中,此视图模型具有绑定到 gridview ItemsSource 的元素集合和表示列标题状态的属性 HeaderChecked。每个元素都有一个属性 IsChecked。当然 ViewModel 支持 INotifyPropertyChanged。

这是一段ViewModel的代码(DataEventsSource 只是实现了 INotifyPropertyChanged):

public class MainViewModel : DataEventsSource
{
    private ObservableCollection<Element> _elements = new ObservableCollection<Element>
                                                          {
                                                              new Element {IsChecked = false},
                                                              new Element {IsChecked = false},
                                                              new Element {IsChecked = false},
                                                              new Element {IsChecked = false}
                                                          };

    public MainViewModel()
    {
        foreach (var element in _elements)
        {
            element.PropertyChanged += OnElementPropertyChanged;
        }
    }

    private void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
    {
        if (e.PropertyName == "IsChecked")
        {
            bool? headerChecked = null;
            if (Elements.All(el => el.IsChecked))
            {
                headerChecked = true;
            }
            if (Elements.All(el => !el.IsChecked))
            {
                headerChecked = false;
            }

            HeaderChecked = headerChecked;
        }

    }

    public ObservableCollection<Element> Elements
    {
        get
        {
            return _elements;
        }
        set
        {
            _elements = value;
        }
    }

    private bool? _headerChecked = false;
    public bool? HeaderChecked
    {
        get
        {
            return _headerChecked;
        }
        set
        {
            _headerChecked = value;
            OnPropertyChanged("HeaderChecked");
        }
    }
}

public class Element : DataEventsSource
{
    private bool _isChecked;
    public bool IsChecked
    {
        get
        {
            return _isChecked;
        }
        set
        {
            _isChecked = value;
            OnPropertyChanged("IsChecked");
        }
    }
}

如您所见,当集合元素发生更改时,HeaderChecked 属性在 OnElementPropertyChanged 方法中更新。

这是观点:

代码隐藏

public partial class MainWindow
{
    private readonly MainViewModel _viewModel = new MainViewModel();

    public MainWindow()
    {
        InitializeComponent();
        DataContext = _viewModel;
    }

    private void CheckBox_Checked(object sender, RoutedEventArgs e)
    {
        foreach (var element in _viewModel.Elements)
        {
            element.IsChecked = true;
        }
    }

    private void CheckBox_UnChecked(object sender, RoutedEventArgs e)
    {
        foreach (var element in _viewModel.Elements)
        {
            element.IsChecked = false;
        }
    }
}

接下来是XAML的主网格(为简单起见,它只包含一列):

<Grid x:Name="LayoutRoot">
    <DataGrid x:Name="dataGrid" CanUserAddRows="False" AutoGenerateColumns="False" ItemsSource="{Binding Elements}">
        <DataGrid.Columns>
            <DataGridCheckBoxColumn x:Name="checkboxColumn" Binding="{Binding IsChecked, Mode=TwoWay}"  IsThreeState="True" Width="50"  >
                <DataGridCheckBoxColumn.HeaderTemplate>
                    <DataTemplate x:Name="dtAllChkBx">
                        <CheckBox Name="cbxAll" Content="Label" IsChecked="{Binding Path=DataContext.HeaderChecked, ElementName=LayoutRoot, Mode=TwoWay}" Checked="CheckBox_Checked"  Unchecked="CheckBox_UnChecked"></CheckBox>
                    </DataTemplate>
                </DataGridCheckBoxColumn.HeaderTemplate>
            </DataGridCheckBoxColumn>
        </DataGrid.Columns>
    </DataGrid>
</Grid>

我希望这段代码对你有帮助,如果我误解了你,请告诉我。

于 2012-04-14T14:08:08.863 回答
1
//this event is for **Checked and UnChecked** of up check box (cbxall)
private void UpCheckbox_Checked(object sender, RoutedEventArgs e)
{
    //checkBox1 = cbxall (your up checkbox)
    if (checkBox1.IsChecked == true)
    {
        dataGrid1.Items.OfType<YourClass>().ToList().ForEach(x => x.IsChecked = true);
    }
    else
    {
        dataGrid1.Items.OfType<YourClass>().ToList().ForEach(x => x.IsChecked = false);
    }
}

//this event is for all other check box
//**Checked and UnChecked** of all other check box is this event
private void OtherCheckbox_Checked(object sender, RoutedEventArgs e)
{
    //checkBox1 = cbxall (your up checkbox)
    if (dataGrid1.Items.OfType<YourClass>().All(x => x.IsChecked == true))
    {
        checkBox1.IsChecked = true;
    }
    else if (dataGrid1.Items.OfType<YourClass>().All(x => x.IsChecked == false))
    {
        checkBox1.IsChecked = false;
    }
    else
    {
        checkBox1.IsChecked = null;
    }
}

...

于 2012-05-08T06:55:43.970 回答