我复制了一些代码并对其进行了修改以适合我的应用程序。我会继续调整和清理代码，直到我对它满意为止。但我遇到了一点错误。我有两个datagridviews并希望将datagridrows从一个移动到另一个。但是，当drag&drop事件全部触发时，dataGridView_Routes_DragDrop()将执行log命令，因为e.Data.GetData中没有数据。我做错了什么？我错过了什么吗？我试图浏览几个指南，但没有具体涉及这个问题。
如何让datagrid将拖动的datagridrow传递给其他数据网格？
/* Drag & Drop */
private Rectangle dragBoxFromMouseDown;
private int rowIndexFromMouseDown;
private void dataGridView_Trips_MouseMove(object sender, MouseEventArgs e)
{
if ((e.Button & MouseButtons.Left) == MouseButtons.Left)
{
// If the mouse moves outside the rectangle, start the drag.
if (dragBoxFromMouseDown != Rectangle.Empty && !dragBoxFromMouseDown.Contains(e.X, e.Y))
{
// Proceed with the drag and drop, passing in the list item.
DragDropEffects dropEffect = dataGridView_Trips.DoDragDrop(dataGridView_Trips.Rows[rowIndexFromMouseDown], DragDropEffects.Copy);
}
}
}
private void dataGridView_Trips_MouseDown(object sender, MouseEventArgs e)
{
// Get the index of the item the mouse is below.
rowIndexFromMouseDown = dataGridView_Trips.HitTest(e.X, e.Y).RowIndex;
if (rowIndexFromMouseDown != -1)
{
// Remember the point where the mouse down occurred.
// The DragSize indicates the size that the mouse can move
// before a drag event should be started.
Size dragSize = SystemInformation.DragSize;
// Create a rectangle using the DragSize, with the mouse position being
// at the center of the rectangle.
dragBoxFromMouseDown = new Rectangle(new Point(e.X - (dragSize.Width / 2), e.Y - (dragSize.Height / 2)), dragSize);
}
else
// Reset the rectangle if the mouse is not over an item in the ListBox.
dragBoxFromMouseDown = Rectangle.Empty;
}
private void dataGridView_Routes_DragOver(object sender, DragEventArgs e)
{
e.Effect = DragDropEffects.Copy;
}
private void dataGridView_Routes_DragDrop(object sender, DragEventArgs e)
{
if (e.Data.GetDataPresent(typeof(DataRowView)))
{
// The mouse locations are relative to the screen, so they must be
// converted to client coordinates.
Point clientPoint = dataGridView_Routes.PointToClient(new Point(e.X, e.Y));
// If the drag operation was a copy then add the row to the other control.
if (e.Effect == DragDropEffects.Copy)
{
DataGridViewRow rowToMove = e.Data(typeof(DataGridViewRow)) as DataGridViewRow;
dataGridView_Routes.Rows.Add(rowToMove);
}
}
else
{
log("Geen data! #01", "Fout");
}
}
/* End Drag & Drop */
答案 0 :(得分：3)
我不知道。但是以下功能已经过调整，并且按预期工作。不太确定以前的代码是如何破坏的。
编辑：typeof是用DataViewRow而不是DataGridViewRow编写的。失败。
private void dataGridView_Routes_DragDrop(object sender, DragEventArgs e)
{
try
{
if (e.Data.GetDataPresent(typeof(DataGridViewRow)))
{
// The mouse locations are relative to the screen, so they must be
// converted to client coordinates.
Point clientPoint = dataGridView_Routes.PointToClient(new Point(e.X, e.Y));
// If the drag operation was a copy then add the row to the other control.
if (e.Effect == DragDropEffects.Copy)
{
DataGridViewRow Row = (DataGridViewRow)e.Data.GetData(typeof(DataGridViewRow));
dataGridView_Routes.Rows.Add(Row.Cells[0].Value, Row.Cells[1].Value, Row.Cells[2].Value);
}
}
else
{
log("Geen data! #01", "Fout");
}
}
catch (Exception msg)
{
log(msg.Message,"Fout");
}
}
答案 1 :(得分：3)
此解决方案适用于将datagridViews绑定到customObjects的人员。它就像一个有多种选择的魅力。建议被接受。
假设您要从datagridview1拖动到datagridview2
//datagridview1 is bound to this BindingList
BindingList<myObject> object_bound_list1;
//datagridview2 is bound to this BindingList
BindingList<myObject> object_bound_list2;
List<myObject> selected_Object_list = new List<myObject>();
List<int> selected_pos_list = new List<int>();
private void dataGridView1_MouseMove(object sender, MouseEventArgs e)
{
if ((e.Button & MouseButtons.Left) == MouseButtons.Left)
{
// Proceed with the drag and drop, passing in the list item.
DragDropEffects dropEffect = dataGridView1.DoDragDrop(
selected_Object_list,
DragDropEffects.Move);
}
}
private void dataGridView1_MouseDown(object sender, MouseEventArgs e)
{
// Get the index of the item the mouse is below.
int rowIndexFromMouseDown = dataGridView1.HitTest(e.X, e.Y).RowIndex;
//if shift key is not pressed
if (Control.ModifierKeys != Keys.Shift && Control.ModifierKeys != Keys.Control)
{
//if row under the mouse is not selected
if (!selected_pos_list.Contains(rowIndexFromMouseDown) && rowIndexFromMouseDown > 0)
{
//if there only one row selected
if (dataGridView1.SelectedRows.Count == 1)
{
//select the row below the mouse
dataGridView.ClearSelection();
dataGridView1.Rows[rowIndexFromMouseDown].Selected = true;
}
}
}
//clear the selection lists
selected_Object_list.Clear();
selected_pos_list.Clear();
//add the selected objects
foreach (DataGridViewRow row in dataGridView1.SelectedRows)
{
selected_Object_list.Add(object_bound_list1[row.Index]);
selected_pos_list.Add(row.Index);
}
}
private void dataGridView2_DragOver(object sender, DragEventArgs e)
{
e.Effect = DragDropEffects.Move;
}
private void dataGridView2_DragDrop(object sender, DragEventArgs e)
{
if (e.Effect == DragDropEffects.Move)
{
foreach (var item in selected_Object_list)
{
object_bound_list2.Add(item);
}
}
}