WPF、Caliburn Micro 和 Dapper - Datagrid 复选框绑定

Question

我在 WPF 项目中使用 Caliburn Micro 和 Dapper，在那里我创建了一个DataGrid ，我用 SQL Server 数据库表中的数据填充。 请考虑以下代码片段：

ChangesModel.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace PTSRDesktopUI.Models
{
    //public class for all changes attributes
    public class ChangesModel
    {
        public int ID { get; set; }
        public string Facility { get; set; }
        public string Controller { get; set; }
        public string ParameterName { get; set; }
        public string OldValue { get; set; }
        public string NewValue { get; set; }
        public DateTime ChangeDate { get; set; }
        public bool Validated { get; set; }
        public DateTime ValidationDate { get; set; }
    }
}

概览视图.xaml

<!--Datagrid Table-->
<DataGrid Grid.Row="1" x:Name="Changes" CanUserAddRows="False" AutoGenerateColumns="False" HorizontalAlignment="Stretch">
    <DataGrid.Columns>
        <DataGridTextColumn CellStyle="{StaticResource DataGridCellCentered}" IsReadOnly="True" 
                            Header="Facility" Binding="{Binding Path=Facility}"/>
        <DataGridTextColumn CellStyle="{StaticResource DataGridCellCentered}" IsReadOnly="True" 
                            Header="Controller" Binding="{Binding Path=Controller}"/>
        <DataGridTextColumn CellStyle="{StaticResource DataGridCellCentered}" IsReadOnly="True" 
                            Header="Parameter" Binding="{Binding Path=ParameterName}"/>
        <DataGridTextColumn CellStyle="{StaticResource DataGridCellCentered}" IsReadOnly="True" 
                            Header="Old Value" Binding="{Binding Path=OldValue}"/>
        <DataGridTextColumn CellStyle="{StaticResource DataGridCellCentered}" IsReadOnly="True" 
                            Header="New Value" Binding="{Binding Path=NewValue}"/>
        <DataGridTextColumn CellStyle="{StaticResource DataGridCellCentered}" IsReadOnly="True" 
                            Header="Changed Date" Binding="{Binding Path=ChangeDate, 
                            StringFormat='{}{0:dd.MM HH:mm}'}"/>
        <DataGridTemplateColumn CellStyle="{StaticResource DataGridCellCentered}" 
                                Header="Validated" IsReadOnly="True">
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate >
                    <CheckBox IsChecked="{Binding Path=Validated}" />
                </DataTemplate>
            </DataGridTemplateColumn.CellTemplate>
        </DataGridTemplateColumn>
        <DataGridTextColumn CellStyle="{StaticResource DataGridCellCentered}" IsReadOnly="True" 
                            Header="Validation Date" Binding="{Binding Path=ValidationDate, 
                            StringFormat='{}{0:dd.MM HH:mm}'}"/>
        <DataGridTemplateColumn CellStyle="{StaticResource DataGridCellCentered}" Header="Validate">
            <DataGridTemplateColumn.CellTemplate>
                <DataTemplate>
                    <Button x:Name="Validate_Btn" cal:Message.Attach="Validate">Validate</Button>
                </DataTemplate>
            </DataGridTemplateColumn.CellTemplate>
        </DataGridTemplateColumn>
    </DataGrid.Columns>
</DataGrid>

概览ViewModel.cs

using Caliburn.Micro;
using PTSRDesktopUI.Helpers;
using PTSRDesktopUI.Models;

namespace PTSRDesktopUI.ViewModels
{
    public class OverviewViewModel : Screen
    {

        //Create new Bindable Collection variable of type ChangesModel
        public BindableCollection<ChangesModel> Changes { get; set; }


        public OverviewViewModel()
        {

            //Create connection to DataAccess class
            DataAccess db = new DataAccess();

            //get the changes from DataAccess function and store them as a bindable collection in Changes
            Changes = new BindableCollection<ChangesModel>(db.GetChanges());

        }

        //Validate_Btn click event
        public void Validate()
        {
           //Some Code        
        }

    }
}

数据访问.cs

//Function to get all changes from database using stored procedures
public List<ChangesModel> GetChanges()
{
    using (IDbConnection connection = new System.Data.SqlClient.SqlConnection(DBHelper.CnnVal("ptsrDB")))
    {
        var output = connection.Query<ChangesModel>("dbo.getChanges").ToList();
        return output;
    }
}

我使用名为getChanges的存储过程从 SQL Server 获取数据。 数据显示出来，一切正常。 我现在想要做的是：首先，我希望Validate_Btn仅在未选中CheckBox行上可见。 其次，如果用户单击Validate_Btn ，我想将CheckBox更改为选中状态，使按钮不可见，并使用 DataAccess 类中的存储过程触发一个新函数，以更新数据库表中Validated的布尔值。 任何人有任何想法我怎么能做到这一点？

Answer 1

要解决第一部分根据CheckBox是否选中来显示和隐藏Button的问题，您应该首先在ChangesModel类中实现INotifyPropertyChanged接口，并在设置Validated属性时引发PropertyChanged事件：

public class ChangesModel : INotifyPropertyChanged
{
    public int ID { get; set; }
    public string Facility { get; set; }
    public string Controller { get; set; }
    public string ParameterName { get; set; }
    public string OldValue { get; set; }
    public string NewValue { get; set; }
    public DateTime ChangeDate { get; set; }

    private bool _validated;
    public bool Validated
    {
        get { return _validated; }
        set { _validated = value; NotifyPropertyChanged(); }
    }

    public DateTime ValidationDate { get; set; }

    public event PropertyChangedEventHandler PropertyChanged; 
    private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")
    {
        PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
    }

}

然后，您可以将Button的Visibility属性绑定到Validated源属性，并使用转换器在bool值和Visibility枚举值之间进行转换：

<DataGridTemplateColumn Header="Validate">
    <DataGridTemplateColumn.CellTemplate>
        <DataTemplate>
            <DataTemplate.Resources>
                <BooleanToVisibilityConverter x:Key="converter" />
            </DataTemplate.Resources>
            <Button x:Name="Validate_Btn" cal:Message.Attach="Validate"
                    Visibility="{Binding Validated, Converter={StaticResource converter}}">Validate</Button>
        </DataTemplate>
    </DataGridTemplateColumn.CellTemplate>
</DataGridTemplateColumn>

您可能还想在CheckBox绑定上设置UpdateSourcePropertyTrigger以立即设置源属性：

<CheckBox IsChecked="{Binding Path=Validated, UpdateSourceTrigger=PropertyChanged}" />

为了在单击按钮时调用Validate() ，您可以将Bind.Model附加属性绑定到视图模型：

<Button x:Name="Validate"
        cal:Bind.Model="{Binding DataContext, 
            RelativeSource={RelativeSource AncestorType=DataGrid}}">Validate</Button>

组合绑定需要指定Visibility绑定的来源：

<Button x:Name="Validate"
    Visibility="{Binding DataContext.Validated, 
       Converter={StaticResource converter}, RelativeSource={RelativeSource AncestorType=DataGridCell}}"
    cal:Bind.Model="{Binding DataContext, RelativeSource={RelativeSource AncestorType=DataGrid}}">Validate</Button>