WPF 后台实现按数字键滚动DataGrid 当前选中项

Posted 2021-02-19 netnotes

　　最近遇到个项目，设备上没有鼠标，界面为全屏的一个DataGrid，需要实现按小键盘的0和1让DataGrid的当前选中行进行上下滚动

　　起到重要参考的是：   https://blog.csdn.net/sinat_31608641/article/details/105428496    实现后台滚动到当前选中项。
      现在把主要实现方式做个笔记：

　　首先，前台一定要设置VirtualizingStackPanel.IsVirtualizing="False"

　　接下来，是两个公共方法：

　　

        /// <summary>
        /// 将SelectedItem滚动为第一行
        /// </summary>
        /// <param name="dataGrid">目标DagaGrid</param>
        /// <param name="selectedItem">选中项</param>
        public static void SetSelectedItemFirstRow(object dataGrid, object selectedItem)
        {
            //若目标datagrid为空，抛出异常
            if (dataGrid == null)
            {
                throw new ArgumentNullException("目标无" + dataGrid + "无法转换为DataGrid");
            }
            //获取目标DataGrid，为空则抛出异常
            System.Windows.Controls.DataGrid dg = dataGrid as System.Windows.Controls.DataGrid;
            if (dg == null)
            {
                throw new ArgumentNullException("目标无" + dataGrid + "无法转换为DataGrid");
            }
            //数据源为空则返回
            if (dg.Items == null || dg.Items.Count < 1)
            {
                return;
            }

            //获取焦点，滚动为目标行
            dg.Focus();
            dg.SelectedItem = selectedItem;
            dg.CurrentColumn = dg.Columns[0];
            dg.ScrollIntoView(dg.SelectedItem, dg.CurrentColumn);
        }

        /// <summary>
        /// 获取选中的行
        /// </summary>
        /// <param name="datagrid"></param>
        /// <param name="rowIndex"></param>
        /// <returns></returns>
        public static DataGridRow GetDataGridRow(DataGrid datagrid, int rowIndex)
        {
            DataGridRow row = (DataGridRow)datagrid.ItemContainerGenerator.ContainerFromIndex(rowIndex);
            if (row == null)
            {
                datagrid.UpdateLayout();

                row = (DataGridRow)datagrid.ItemContainerGenerator.ContainerFromIndex(rowIndex);
                row.IsSelected = true;
            }
            return row;
        } 

　　然后，添加一个窗体的KeyDown事件：

　　

     private void UserControl_KeyDown(object sender, KeyEventArgs e)
        {
            dgvDeal.Focus();
            if (e.Key==Key.NumPad0)
            {
                if (dgvDeal.SelectedIndex == dgvDeal.Items.Count-1)
                {
                    dgvDeal.SelectedIndex = 0; 
                }
                else
                {
                    dgvDeal.SelectedIndex = dgvDeal.SelectedIndex + 1; 
                }
            }
            else if (e.Key == Key.NumPad1)
            {
                if (dgvDeal.SelectedIndex == 0)
                {
                    dgvDeal.SelectedIndex = dgvDeal.Items.Count-1; 
                }
                else
                {
                    dgvDeal.SelectedIndex = dgvDeal.SelectedIndex - 1; 
                }
            }
              
            DataGridRow resRow = GetDataGridRow(dgvDeal, dgvDeal.SelectedIndex);
            resRow.IsSelected = true;
            SetSelectedItemFirstRow(dgvDeal, dgvDeal.SelectedItem);
             
        }

 

          OK!