Select DataGridCell from DataGrid

问题:

I have a DataGrid WPF control and I want to get a specific DataGridCell. I know the row and column indices. How can I do this?

I need the DataGridCell because I have to have access to its Content. So if I have (for example) a column of DataGridTextColum, my Content will be a TextBlock object.

回答1:

You can use code similar to this to select a cell:

var dataGridCellInfo = new DataGridCellInfo(
    dataGrid.Items[rowNo], dataGrid.Columns[colNo]);

dataGrid.SelectedCells.Clear();
dataGrid.SelectedCells.Add(dataGridCellInfo);
dataGrid.CurrentCell = dataGridCellInfo;

I can't see a way to update the contents of a specific cell directly, so in order to update the content of a specific cell I would do the following

// gets the data item bound to the row that contains the current cell
// and casts to your data type.
var item = dataGrid.CurrentItem as MyDataItem;

if(item != null){
    // update the property on your item associated with column 'n'
    item.MyProperty = "new value";
}
// assuming your data item implements INotifyPropertyChanged the cell will be updated.

回答2:

You can simply use this extension method-

public static DataGridRow GetSelectedRow(this DataGrid grid)
{
    return (DataGridRow)grid.ItemContainerGenerator.ContainerFromItem(grid.SelectedItem);
}

and you can get a cell of a DataGrid by an existing row and column id:

public static DataGridCell GetCell(this DataGrid grid, DataGridRow row, int column)
{
    if (row != null)
    {
        DataGridCellsPresenter presenter = GetVisualChild<DataGridCellsPresenter>(row);

        if (presenter == null)
        {
            grid.ScrollIntoView(row, grid.Columns[column]);
            presenter = GetVisualChild<DataGridCellsPresenter>(row);
        }

        DataGridCell cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(column);
        return cell;
    }
    return null;
}

grid.ScrollIntoView is the key to make this work in case DataGrid is virtualized and required cell is not in view currently.

Check this link for details - Get WPF DataGrid row and cell

回答3:

Here is the code I used:

    /// <summary>
    /// Get the cell of the datagrid.
    /// </summary>
    /// <param name="dataGrid">The data grid in question</param>
    /// <param name="cellInfo">The cell information for a row of that datagrid</param>
    /// <param name="cellIndex">The row index of the cell to find. </param>
    /// <returns>The cell or null</returns>
    private DataGridCell TryToFindGridCell(DataGrid dataGrid, DataGridCellInfo cellInfo, int cellIndex = -1)
    {
        DataGridRow row;
        DataGridCell result = null;

        if (dataGrid != null && cellInfo != null)
        {
            if (cellIndex < 0)
            {
                row = (DataGridRow)dataGrid.ItemContainerGenerator.ContainerFromItem(cellInfo.Item);
            }
            else
            {
                row = (DataGridRow)dataGrid.ItemContainerGenerator.ContainerFromIndex(cellIndex);
            }

            if (row != null)
            {
                int columnIndex = dataGrid.Columns.IndexOf(cellInfo.Column);

                if (columnIndex > -1)
                {
                    DataGridCellsPresenter presenter = this.FindVisualChild<DataGridCellsPresenter>(row);

                    if (presenter != null)
                    {
                        result = presenter.ItemContainerGenerator.ContainerFromIndex(columnIndex) as DataGridCell;
                    }
                    else
                    {
                        result = null;
                    }
                }
            }
        }

        return result;
    }`

This assumes that the DataGrid has already been loaded (executed its own Loaded handler).