我在互聯網上看到這個主題很常見,我不明白爲什麼還沒有創建一個方法來直接選擇datagridview中的單元。在datagridview中選擇一個單元並開始編輯
我創建了這個類助手:
using Microsoft.Windows.Controls.Primitives;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Controls;
using System.Windows.Media;
namespace gestione_magazzino_v4.Classi
{
static class DataGridViewHelper
{
static public DataGridCell GetCell(DataGrid dg, int row, int column)
{
DataGridRow rowContainer = GetRow(dg, row);
if (rowContainer != null)
{
DataGridCellsPresenter presenter = GetVisualChild<DataGridCellsPresenter>(rowContainer);
DataGridCell cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(column); // <<<------ ERROR
if (cell == null)
{
// now try to bring into view and retreive the cell
dg.ScrollIntoView(rowContainer, dg.Columns[column]);
cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(column);
}
return cell;
}
return null;
}
static public DataGridRow GetRow(DataGrid dg, int index)
{
DataGridRow row = (DataGridRow)dg.ItemContainerGenerator.ContainerFromIndex(index);
if (row == null)
{
// may be virtualized, bring into view and try again
dg.ScrollIntoView(dg.Items[index]);
row = (DataGridRow)dg.ItemContainerGenerator.ContainerFromIndex(index);
}
return row;
}
static T GetVisualChild<T>(Visual parent) where T : Visual
{
T child = default(T);
int numVisuals = VisualTreeHelper.GetChildrenCount(parent);
for (int i = 0; i < numVisuals; i++)
{
Visual v = (Visual)VisualTreeHelper.GetChild(parent, i);
child = v as T;
if (child == null)
{
child = GetVisualChild<T>(v);
}
if (child != null)
{
break;
}
}
return child;
}
}
}
我用這個代碼:
DataGridCell cell = DataGridViewHelper.GetCell(datagridview, 0, 2);
if (cell != null)
cell.Focus();
但我得到一個錯誤,我特別強調了,我得到System.NullReferenceException
我不明白缺少什麼...網上有很多例子,但它們都與我所做的相同,不明白什麼是失蹤!
你能與調試器附加檢查該'presenter'爲空? –
是...'presenter' si null ...是'GetVisualChild'返回值始終爲空... – user2263764