c# - 选中数据网格标题中的所有复选框及其在 wpf mvvm 中的绑定(bind)

Question

我正在研究 wpf(mvvm 架构)。我正在使用数据网格在标题中列出复选框和 SELECT ALL 复选框，单击我希望选中所有复选框，反之亦然。请帮忙。

我在这里给出我的代码描述......
这是 View.xaml

<DataGridCheckBoxColumn Binding="{Binding IsSelected}" Width="50" >
    <DataGridCheckBoxColumn.HeaderTemplate>
        <DataTemplate x:Name="dtAllChkBx">
            <CheckBox Name="cbxAll" Content="All" IsChecked="{Binding Path=DataContext.AllSelected,RelativeSource={RelativeSource AncestorType=DataGrid}}"/>
        </DataTemplate>
    </DataGridCheckBoxColumn.HeaderTemplate>
</DataGridCheckBoxColumn>
<DataGridTemplateColumn Header="Name" Width="SizeToCells" IsReadOnly="True">
    <DataGridTemplateColumn.CellTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding UsecaseName}" />
        </DataTemplate>
    </DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>             

下面是 View 模型类

private bool _IsSelected;
public bool IsSelected
{
    get { return _IsSelected; }
    set
    {
        _IsSelected = value;
        OnPropertyChanged("IsSelected");
    }
}

private bool _AllSelected;
public bool AllSelected
{
    get { return _AllSelected; }
    set
    {
        _AllSelected = value;
        foreach (var reportListItemModel in UsecaseListItems)
        {
            reportListItemModel.IsSelected = this._AllSelected;
        }
        OnPropertyChanged("IsSelected");

    }
}   

private ObservableCollection<UseCase> _usecaseListItems = new ObservableCollection<UseCase>();
public ObservableCollection<UseCase> UsecaseListItems
{
    get { return _usecaseListItems; }
    set {
        _usecaseListItems = value;
        OnPropertyChanged("UsecaseListItems");
    }
}

公共(public)类用例:BaseNotifyPropertyChanged
{
公共(public)字符串 UsecaseName { 获取；放; }

    public bool IsSelected { get; set; }

}

还应该做什么才能使全选复选框正常工作？

Answer 1

你的 UseCase 类必须实现 INotifyPropertyChanged 界面

public class UseCase : INotifyPropertyChanged
{
    //...
    private bool _isSelected;
    public bool IsSelected
    {
        get
        {
            return _isSelected;
        }
        set
        {
            _isSelected = value;
            NotifyPropertyChanged("IsSelected");
        }
    }
    public event PropertyChangedEventHandler PropertyChanged;
    protected void NotifyPropertyChanged(String info)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(info));
        }
    }
}

编辑 :在这里我得到了一个运行良好的完整示例

*.xaml(查看)

<DataGrid x:Name="dataGrid" ItemsSource="{Binding MyCollection}" AutoGenerateColumns="False">
    <DataGrid.Columns>
        <DataGridCheckBoxColumn Binding="{Binding IsSelected}" Width="50" >
            <DataGridCheckBoxColumn.HeaderTemplate>
                <DataTemplate x:Name="dtAllChkBx">
                    <CheckBox Name="cbxAll" DataContext="{Binding ElementName=dataGrid, Path=DataContext}" Command="{Binding MyCommand}" CommandParameter="{Binding Path=IsChecked, RelativeSource={RelativeSource Self}}"/>
                </DataTemplate>
            </DataGridCheckBoxColumn.HeaderTemplate>
        </DataGridCheckBoxColumn>
        <DataGridTemplateColumn Header="Name" Width="SizeToCells" IsReadOnly="True">
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                    <TextBlock Text="{Binding UsecaseName}" />
                </DataTemplate>
            </DataGridTemplateColumn.CellTemplate>
        </DataGridTemplateColumn>
    </DataGrid.Columns>
</DataGrid>

*.cs( View 模型)

public class MainViewModel : INotifyPropertyChanged
{
    public MainViewModel()
    {
        for (int i = 0; i < 100; i++)
        {
            MyCollection.Add(new UseCase { UsecaseName = "name " + i, IsSelected = false });
        }
        MyCommand = new RelayCommand(MyCommandAction);
    }


    private ObservableCollection<UseCase> myCollection = new ObservableCollection<UseCase>();

    public ObservableCollection<UseCase> MyCollection
    {
        get
        {
            return myCollection;
        }
        set
        {
            myCollection = value;
            NotifyPropertyChanged("MyCollection");
        }
    }

    public RelayCommand MyCommand { get; set; }
    private  void MyCommandAction(object obj)
    {
        foreach (var item in MyCollection)
        {
            item.IsSelected = (bool)obj;
        }
    }



    //NotifyPropertyChanged
    public event PropertyChangedEventHandler PropertyChanged;
    protected void NotifyPropertyChanged(String info)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(info));
        }
    }
}

*.cs(型号)

public class UseCase : INotifyPropertyChanged
{
    public string UsecaseName { get; set; }
    private bool _isSelected;
    public bool IsSelected
    {
        get
        {
            return _isSelected;
        }
        set
        {
            _isSelected = value;
            NotifyPropertyChanged("IsSelected");
        }
    }
    public event PropertyChangedEventHandler PropertyChanged;
    protected void NotifyPropertyChanged(String info)
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(info));
        }
    }
}