private void fl_DropOverItem(object sender, DragOverItemEventArgs e)
{
var text = (e.Data.GetData(typeof(Label)) as Label).Text;
switch (e.InsertEffect)
{
case InsertEffect.InsertBefore:
list.Insert(e.ItemIndex, text);
fl.ItemCount = list.Count;
break;
case InsertEffect.InsertAfter:
list.Insert(e.ItemIndex + 1, text);
fl.ItemCount = list.Count;
break;
case InsertEffect.Replace:
if (MessageBox.Show("Are you sure to replace item?", "Replace", MessageBoxButtons.OKCancel) == DialogResult.OK)
{
list[e.ItemIndex] = text;
fl.Invalidate();
}
break;
}
}
private void fl_DragOverItem(object sender, DragOverItemEventArgs e)
{
var lb = e.Data.GetData(typeof (Label)) as Label;
if (lb == lbRegular)
{
e.Effect = e.AllowedEffect;
return;
}
if (lb == lbAfter13 && list[e.ItemIndex] == "Item 13")
{
e.Effect = e.AllowedEffect;
e.InsertEffect = InsertEffect.InsertAfter;
return;
}
if (lb == lbEndOfList)
{
e.Effect = e.AllowedEffect;
e.InsertEffect = InsertEffect.InsertAfter;
e.ItemIndex = list.Count - 1;
return;
}
if (lb == lbReplace)
{
e.Effect = DragDropEffects.Move;
e.InsertEffect = InsertEffect.Replace;
return;
}
e.Effect = DragDropEffects.None;
}
protected virtual void DrawDragOverInsertEffect(Graphics gr, DragOverItemEventArgs e)
{
var c1 = Color.FromArgb(SelectionColor.A == 255 ? SelectionColorOpaque : SelectionColor.A, SelectionColor);
var c2 = Color.Transparent;
if (!visibleItemInfos.ContainsKey(e.ItemIndex))
return;
var info = visibleItemInfos[e.ItemIndex];
var rect = new Rectangle(info.X_ExpandBox, info.Y, 1000, info.Height);
switch (e.InsertEffect)
{
case InsertEffect.Replace:
using (var brush = new SolidBrush(c1))
gr.FillRectangle(brush, rect);
break;
case InsertEffect.InsertBefore:
if (e.ItemIndex <= 0)
rect.Offset(0, 2);
using (var pen = new Pen(c1, 2) { DashStyle = DashStyle.Dash })
gr.DrawLine(pen, rect.Left, rect.Top, rect.Right, rect.Top);
break;
case InsertEffect.InsertAfter:
if (e.ItemIndex < 0)
rect.Offset(0, 2);
using (var pen = new Pen(c1, 2) { DashStyle = DashStyle.Dash })
gr.DrawLine(pen, rect.Left, rect.Bottom, rect.Right, rect.Bottom);
break;
case InsertEffect.AddAsChild:
if (e.ItemIndex >= 0 && e.ItemIndex < ItemCount)
{
var dx = GetItemIndent(e.ItemIndex) + 80;
rect.Offset(dx, 0);
using (var pen = new Pen(c1, 2) { DashStyle = DashStyle.Dash })
gr.DrawLine(pen, rect.Left, rect.Bottom, rect.Right, rect.Bottom);
}
break;
}
}
protected virtual void OnDropOverItem(DragOverItemEventArgs e)
{
}
protected virtual void OnDragOverItem(DragOverItemEventArgs e)
{
if (e.Y < e.ItemRect.Y + e.ItemRect.Height / 2)
e.InsertEffect = InsertEffect.InsertBefore;
else
e.InsertEffect = InsertEffect.InsertAfter;
}
protected override void OnDragOver(DragEventArgs e)
{
var p = new Point(e.X, e.Y);
p = PointToClient(p);
var itemIndex = YToIndexAround(p.Y + VerticalScroll.Value);
var rect = CalcItemRect(itemIndex);
var textRect = rect;
if (visibleItemInfos.ContainsKey(itemIndex))
{
var info = visibleItemInfos[itemIndex];
textRect = new Rectangle(info.X_Text, rect.Y, info.X_EndText - info.X_Text + 1, rect.Height);
}
var ea = new DragOverItemEventArgs(e.Data, e.KeyState, p.X, p.Y, e.AllowedEffect, e.Effect, rect, textRect) { ItemIndex = itemIndex };
OnDragOverItem(ea);
if (ea.Effect != DragDropEffects.None)
lastDragAndDropEffect = ea;
else
lastDragAndDropEffect = null;
e.Effect = ea.Effect;
//scroll
if (ea.ItemIndex >= 0 && ea.ItemIndex < ItemCount && itemIndex != ea.ItemIndex)
{
rect = CalcItemRect(ea.ItemIndex);
rect.Inflate(0, 2);
rect.Offset(HorizontalScroll.Value, VerticalScroll.Value);
ScrollToRectangle(rect);
}
else
{
if (p.Y <= Padding.Top + ItemHeightDefault / 2)
ScrollUp();
else if (p.Y >= ClientSize.Height - Padding.Bottom - +ItemHeightDefault / 2)
ScrollDown();
}
Invalidate();
//base.OnDragOver(e);
}
protected override void OnDragLeave(EventArgs e)
{
base.OnDragLeave(e);
lastDragAndDropEffect = null;
Invalidate();
}
protected override void OnDragDrop(DragEventArgs e)
{
base.OnDragDrop(e);
if (lastDragAndDropEffect != null)
OnDropOverItem(lastDragAndDropEffect);
lastDragAndDropEffect = null;
Invalidate();
}
protected virtual void DrawDragOverInsertEffect(Graphics gr, DragOverItemEventArgs e)
{
var c1 = Color.FromArgb(SelectionColor.A == 255 ? SelectionColorOpaque : SelectionColor.A, SelectionColor);
var c2 = Color.Transparent;
var rect = CalcItemRect(e.ItemIndex);
switch(e.InsertEffect)
{
case InsertEffect.Replace:
using (var brush = new SolidBrush(c1))
gr.FillRectangle(brush, rect);
break;
case InsertEffect.InsertBefore:
if (e.ItemIndex <= 0)
rect.Offset(0, 2);
using (var pen = new Pen(c1, 2) { DashStyle = DashStyle.Dash })
gr.DrawLine(pen, rect.Left, rect.Top, rect.Right, rect.Top);
break;
case InsertEffect.InsertAfter:
if (e.ItemIndex < 0)
rect.Offset(0, 2);
using (var pen = new Pen(c1, 2) { DashStyle = DashStyle.Dash })
gr.DrawLine(pen , rect.Left, rect.Bottom, rect.Right, rect.Bottom);
break;
case InsertEffect.AddAsChild:
if (e.ItemIndex >= 0 && e.ItemIndex < ItemCount)
{
var dx = GetItemIndent(e.ItemIndex) + 16;
rect.Offset(dx, 0);
using (var pen = new Pen(c1, 2) {DashStyle = DashStyle.Dash})
gr.DrawLine(pen, rect.Left, rect.Bottom, rect.Right, rect.Bottom);
}
break;
}
}
