//计算所有Item的大小
public void MeasureItems()
{
//计算每个项目的高度
int totleItemHeight = 0;
int height = 0;
using (Graphics g = this.CreateGraphics())
{
for (int i = 0; i < this.Items.Count; i++)
{
ScrollableListItem item = this.Items[i];
//计算描画矩形区域
item.Width = this.ClientSize.Width;
OnMeasureItem(new MeasureItemEventArgs(item, g, this.Font));
//重新设定Y的位置
item.X = 0;
item.Y = height + Offset;
totleItemHeight += item.Height;
height += item.Height;
}
}
this.TotleItemHeight = totleItemHeight;
}
public void Insert(int pos, ScrollableListItem item)
{
List <ScrollableListItem> col = new List <ScrollableListItem>();
col.Add(item);
InsertRange(pos, col);
}
internal void MeasureItemOnAdd(ScrollableListItem item)
{
List <ScrollableListItem> list = new List <ScrollableListItem>(1);
list.Add(item);
MeasureItemOnAdd(list);
}
public void Remove(ScrollableListItem item)
{
this._list.Remove(item);
if (this._owner != null)
{
this._owner.MeasureItemOnRemove(item);
this._owner.Invalidate();
}
}
public void Add(ScrollableListItem item)
{
this._list.Add(item);
if (this._owner != null)
{
this._owner.MeasureItemOnAdd(item);
this._owner.Invalidate();
}
}
internal void MeasureItemOnRemove(ScrollableListItem item)
{
//using (Graphics g = this.CreateGraphics())
//{
//删除的项应该不需要再计算了，反正都删除了，是吧？
//OnMeasureItem(new MeasureItemEventArgs(this.Items.IndexOf(item), item, g, this.Font));
this.TotleItemHeight -= item.Height;
//}
}
public void RemoveAt(int index)
{
ScrollableListItem item = this._list[index];
this._list.RemoveAt(index);
if (this._owner != null)
{
this._owner.MeasureItemOnRemove(item);
this._owner.Invalidate();
}
}
protected override void OnMouseClick(MouseEventArgs e)
{
base.OnMouseClick(e);
ScrollableListItem item = HitTest(e.Location);
if (item == null)
{
return;
}
//设置选择状态
bool bSelectChange = false;
if (item.Selected)
{
if (this.ToggleSelection)
{
item.Selected = false;
this.SelectedItems.Remove(item);
bSelectChange = true;
}
}
else
{
if (!this.MultipleSelect)
{
//只能单选时
foreach (ScrollableListItem i in this.SelectedItems)
{
i.Selected = false;
}
this.SelectedItems.Clear();
}
item.Selected = true;
this.SelectedItems.Add(item);
bSelectChange = true;
}
//触发点击事件
ItemClickedEventArgs args = new ItemClickedEventArgs(item, e.Button, e.Location);
OnItemClicked(args);
if (bSelectChange)
{
//触发选择变化事件
OnSelectionChanged(new EventArgs());
}
//描绘选择状态
this.Invalidate(item.Bounds);
}
private void ResetItemsBounds()
{
int height = 0;
for (int i = 0; i < this.Items.Count; i++)
{
ScrollableListItem item = this.Items[i];
item.Y = height + Offset;
height += item.Height;
}
}
public DrawItemEventArgs(ScrollableListItem item,
Graphics g, bool focus, bool selected,
Font font, Color foreColor, Color backColor)
{
this.Item = item;
this.Graphics = g;
this.Font = font;
this.ForeColor = foreColor;
this.BackColor = backColor;
this.SelectedBackColor = LanColor.DarkLight(backColor, -0.06f);
this.FocusBackColor = LanColor.DarkLight(backColor, -0.03f);
this.Focus = focus;
this.Selected = selected;
}
private ScrollableListItem HitTest(Point mousePosition)
{
for (int i = 0; i < this.Items.Count; i++)
{
ScrollableListItem item = this.Items[i];
Rectangle rect = item.Bounds;
if (rect.Contains(mousePosition))
{
return(item);
}
}
return(null);
}
protected virtual void OnDrawItems(Graphics g, Rectangle clipRect)
{
for (int i = 0; i < this.Items.Count; i++)
{
ScrollableListItem item = this.Items[i];
Rectangle rect = item.Bounds;
if (rect.IntersectsWith(clipRect))
{
//不在拖拽滑块，并且鼠标移动到上面就定为Focus
bool isFocus = (this.HighlightWithNoFocus || !this.HighlightWithNoFocus && this.Focused) &&
!this._scrollBarHandleDrag && rect.Contains(PointToClient(MousePosition));
DrawItemEventArgs args = new DrawItemEventArgs(item, g, isFocus, item.Selected,
this.Font, this.ForeColor, this.BackColor);
OnDrawItem(args);
}
}
}
protected override void OnMouseMove(MouseEventArgs e)
{
base.OnMouseMove(e);
//滚动条区域重绘
if (this._scrollBarHandleDrag)
{
//鼠标按下时拖动，更新滑块偏移
this.Offset -= (int)(1.0 * (e.Y - this._scrollBarHandleDragMouseOffsetY) * this._totleItemHeight / this.ClientSize.Height);
this._scrollBarHandleDragMouseOffsetY = e.Y;
}
else
{
//更新滑块的画刷
bool focusHandle = this._scrollBarHandleBounds.Contains(e.Location);
if (focusHandle &&
this._scrollBarHandleBrush != SCROLLBAR_HANDLE_BRUSH_FOCUSED)
{
//鼠标移动到上面时候绘制Foused的深色
this._scrollBarHandleBrush = SCROLLBAR_HANDLE_BRUSH_FOCUSED;
}
else if (!focusHandle &&
this._scrollBarHandleBrush != SCROLLBAR_HANDLE_BRUSH_NORMAL)
{
this._scrollBarHandleBrush = SCROLLBAR_HANDLE_BRUSH_NORMAL;
}
}
ScrollableListItem item = HitTest(e.Location);
if (item != null)
{
//触发Hover事件
ItemHoverEventArgs args = new ItemHoverEventArgs(item, e.Location);
OnItemHover(args);
}
this.Invalidate();
}
public MeasureItemEventArgs(ScrollableListItem item, Graphics g, Font font)
{
this.Item = item;
this.Graphics = g;
this.Font = font;
}
public ItemHoverEventArgs(ScrollableListItem item, Point loc)
{
this.Item = item;
this.Location = loc;
}
public ItemClickedEventArgs(ScrollableListItem item, MouseButtons button, Point loc)
{
this.Item = item;
this.Button = button;
this.Location = loc;
}
public int IndexOf(ScrollableListItem item)
{
return(this._list.IndexOf(item));
}
