DEV GridView拖动

基本逻辑

• 只需要添加三个事件即可

// hit info
private GridHitInfo gridHitInfo = null;
private Point prePoint = new Point();
private void gridView_Main_MouseDown(object sender, MouseEventArgs e)
{
    gridHitInfo = null;
    var hitInfo = gridView_Main.CalcHitInfo(new Point(e.X, e.Y));
    if (e.Button == MouseButtons.Left && hitInfo.InRow && hitInfo.RowHandle != GridControl.NewItemRowHandle)
    {
        gridHitInfo = hitInfo;
        prePoint = new Point(e.X, e.Y);
    }

}
private void gridView_Main_MouseMove(object sender, MouseEventArgs e)
{
    if (e.Button != MouseButtons.Left || gridHitInfo == null)
        return;
    var dragSize = SystemInformation.DragSize;
    var dragRec = new Rectangle(new Point(gridHitInfo.HitPoint.X - dragSize.Width / 2, gridHitInfo.HitPoint.Y - dragSize.Height / 2), dragSize);
    if (!dragRec.Contains(new Point(e.X, e.Y)))
    {
       //must set gridcontrol.allowdrop=true 
        gridView_Main.GridControl.DoDragDrop(gridHitInfo, DragDropEffects.Move);
        gridHitInfo = null;
        foreach (DataRow eachRow in dtMain.Rows)
	    {
	        eachRow["序号"] = dtMain.Rows.IndexOf(eachRow) + 1;
	    }
    }
    
}
private void gridControl_Main_DragOver(object sender, DragEventArgs e)
{
    if (e.Data.GetDataPresent(typeof(GridHitInfo)))
    {
        var downHitInfo = e.Data.GetData(typeof(GridHitInfo)) as GridHitInfo;
        if (downHitInfo == null)
        {
            return;
        }
        var hitInfo = gridView_Main.CalcHitInfo(gridControl_Main.PointToClient(new Point(e.X, e.Y)));
        if (hitInfo.InRow && hitInfo.RowHandle != downHitInfo.RowHandle && hitInfo.RowHandle != GridControl.NewItemRowHandle)
            e.Effect = DragDropEffects.Move;
        else
            e.Effect = DragDropEffects.None;

    }
}
private void gridControl_Main_DragDrop(object sender, DragEventArgs e)
{
    GridHitInfo srcHitInfo = e.Data.GetData(typeof(GridHitInfo)) as GridHitInfo;
    GridHitInfo hitInfo = gridView_Main.CalcHitInfo(gridControl_Main.PointToClient(new Point(e.X, e.Y)));

    var curPoint = gridControl_Main.PointToClient(new Point(e.X, e.Y));
    //compare y  to judge direction(not use)
    var dy = curPoint.Y - prePoint.Y;
    MoveRow(srcHitInfo.RowHandle, hitInfo.RowHandle);

}
private void MoveRow(int sourceRowHandle, int targetRowHandle)
{
    if (sourceRowHandle == targetRowHandle)
        return;
    DataRow targetRow = gridView_Main.GetDataRow(targetRowHandle);
    DataRow sourceRow = gridView_Main.GetDataRow(sourceRowHandle);

    object[] objArray = sourceRow.ItemArray;
    var dragRowCopy = dtMain.NewRow();
    dragRowCopy.ItemArray = objArray;
    sourceRow.Delete();
    dtMain.Rows.InsertAt(dragRowCopy, targetRowHandle);
    gridView_Main.FocusedRowHandle = targetRowHandle;
}

• 以上省去了一些步骤，只允许是在控件格内移动而不可以拖动到外面，如果需要的话，可以使用prePoint跟现在的点的坐标对比，算出水平和竖直的差是正还是负。