WPF C＃从自动生成的数据网格和数据表中获取单元格值

Question

我为数据表创建了简单的机制xaml看起来很简单：

<DataGrid ItemsSource="{Binding CurrentsFlagValuesView}" AutoGenerateColumns="True" />

后面的MVVM代码基于数据表，而且相当简单：

private void GenerateDataView()
{
    CurrentsFlagValuesView = new DataTable();
    CurrentsFlagValuesView.Columns.Add("Bits");

    var bitLength = 0;

    foreach (CurrentsFlagAnalysis flag in CurrentsFlagValues)
    {
        CurrentsFlagValuesView.Columns.Add(flag.DailyCurrentsTimestampInterval.ToString("yyyy-MM-dd"));
        bitLength = flag.CurrentFlagsLength;
    }

    for (var bit = 0; bit < bitLength; bit++)
    {
        List<CurrentFlagEventEnum> flags = CurrentsFlagValues
            .Select(value => value.CurrentFlags.ElementAt(bit))
            .Select(value => value ? (CurrentFlagEventEnum)bit + 1 : CurrentFlagEventEnum.None)
            .ToList();

        var dataRowValues = new List<object> { bit };
        dataRowValues.AddRange(flags.Cast<object>());

        CurrentsFlagValuesView.Rows.Add(dataRowValues.ToArray());
    }
}

但是当我点击单元格（如列标题和单元格的值）时，我遇到了一个问题或者两个我想获取单元格数据的问题。我设法在没有MVVM的情况下这样做：

void EditingDataGrid_CurrentCellChanged(object sender, EventArgs e)
{
    DataGridCell Cell = EditingDataGrid.GetCurrentDataGridCell();
    var Position = Cell.PointToScreen(new Point(0, 0));

    TextBlock text = (TextBlock)Cell.Content;

    MessageBox.Show("Value=" + text.Text, "Position" );
}

public static DataGridCell GetCurrentDataGridCell(this DataGrid dataGrid)
{
    DataGridCellInfo cellInfo = dataGrid.CurrentCell;
    if (cellInfo.IsValid == false)
    {
        return null;
    }
    var cellContent = cellInfo.Column.GetCellContent(cellInfo.Item);
    if (cellContent == null)
    {
        return null;
    }
    return cellContent.Parent as DataGridCell;
}

但现在我想改造那种模式，但我不知道如何。任何想法如何绑定命令？

Answer 1

您可以将CurrentCell的DataGrid属性绑定到DataGridCellInfo（而不是DataGridCell）源属性，前提是您设置Mode的Binding两个TwoWay：

<DataGrid ItemsSource="{Binding CurrentsFlagValuesView}" 
          CurrentCell="{Binding CurrentCell, Mode=TwoWay}"
          AutoGenerateColumns="True" />

然后，只要在视图中选择单元格，就会设置视图模型的source属性，您只需将当前逻辑移动到视图模型：

private DataGridCellInfo _currentCell;
public DataGridCellInfo CurrentCell
{
    get { return _currentCell; }
    set { _currentCell = value; OnCurrentCellChanged(); }
}

void OnCurrentCellChanged()
{
    DataGridCell Cell = GetCurrentDataGridCell(_currentCell);
    var Position = Cell.PointToScreen(new Point(0, 0));

    TextBlock text = (TextBlock)Cell.Content;
    MessageBox.Show("Value=" + text.Text, "Position");
}

public static DataGridCell GetCurrentDataGridCell(DataGridCellInfo cellInfo)
{
    if (cellInfo == null || cellInfo.IsValid == false)
    {
        return null;
    }
    var cellContent = cellInfo.Column.GetCellContent(cellInfo.Item);
    if (cellContent == null)
    {
        return null;
    }
    return cellContent.Parent as DataGridCell;
}

您还可以将此功能包装在将视图模型的source属性设置为actuall单元格值的行为中：

https://www.codeproject.com/Articles/28959/Introduction-to-Attached-Behaviors-in-WPF https://blog.magnusmontin.net/2014/01/30/wpf-using-behaviours-to-bind-to-readonly-properties-in-mvvm/

Answer 2

您可以简单地绑定视图模型中的当前单元格属性，您将始终拥有当前单元格：

      <DataGrid AutoGenerateColumns="True" 
      SelectionUnit="Cell" 
      CanUserDeleteRows="True" 
      ItemsSource="{Binding Results}" 
      CurrentCell="{Binding CellInfo}"            
      SelectionMode="Single">

在视图模型中：

private DataGridCell cellInfo;
public DataGridCell CellInfo
{
    get { return cellInfo; }
}