C#实现的下拉多选框，下拉多选树，多级节点
今天给大家上个硬货，下拉多选框，同时也是下拉多选树，支持父节点跟子节点！该控件是基于Telerik控件封装实现的，所以大家在使用的过程中需要引用Telerik.WinControls.dll、Telerik.WinControls.UI.dll，还有一些相关的类库，大家有需要的可以去网上自己找，另外我也会把一些动态库放到CSDN上面，大家需要可以去下载。
[ToolboxItem(true)]public partial classDropDownTreeViewControl : RadControl
{public DropDownTreeViewElement TreeViewElement { get; private set; }publicRadTreeView TreeViewControl
{get{return this.TreeViewElement.TreeViewControl;
}
}protected override voidCreateChildItems(RadElement parent)
{this.AllowShowFocusCues = true;base.CreateChildItems(parent);this.TreeViewElement = newDropDownTreeViewElement();
parent.Children.Add(TreeViewElement);
}protected override voidOnEnter(EventArgs e)
{base.OnEnter(e);this.TreeViewElement.Focus();
}protected override voidOnBindingContextChanged(EventArgs e)
{base.OnBindingContextChanged(e);this.TreeViewControl.BindingContext = this.BindingContext;
}public classDropDownTreeViewElement : LightVisualElement
{private readonly Color BG_COLOR =Color.White;private readonly Color BORDER_COLOR =Color.LightBlue;private readonly Color ARROW_BORDER_COLOR =Color.LightGray;private readonly Color ARROW_NORMAL_BG_COLOR =Color.White;private readonly Color ARROW_MOUSE_OVER_BG_COLOR =Color.LightYellow;private readonly Color ARROW_PRESSED_BG_COLOR =Color.DarkOrange;private readonly int NORMAL_BORDER_WIDTH = 1;private readonly int FOCUS_BORDER_WIDTH = 2;privateRadArrowButtonElement arrow;privatePopupForm popup;private boolisInnerCallHide;public bool IsPopupOpen { get; private set; }publicRadTreeView TreeViewControl
{get{return this.popup.TreeView;
}
}protected override voidInitializeFields()
{base.InitializeFields();//style this.DrawBorder = true;this.BorderBoxStyle =BorderBoxStyle.SingleBorder;this.BorderGradientStyle =GradientStyles.Solid;this.BorderColor =BORDER_COLOR;this.DrawFill = true;this.NumberOfColors = 1;this.GradientStyle =GradientStyles.Solid;this.BackColor =BG_COLOR;this.StretchHorizontally = true;this.StretchVertically = true;
}protected override voidCreateChildElements()
{base.CreateChildElements();//arrow this.CreateArrow();//popup this.CreatePopup();this.Children.Add(arrow);
}private voidCreatePopup()
{this.popup = new PopupForm(this);this.popup.PopupClosing +=Popup_PopupClosing;this.popup.PopupClosed +=Popup_PopupClosed;
}private void Popup_PopupClosing(objectsender, RadPopupClosingEventArgs args)
{//mouse postion in control-bounds prevent if (args.CloseReason ==RadPopupCloseReason.Mouse)
{var boundsSc = RectangleToScreen(this.Bounds);if(boundsSc.Contains(MousePosition))
{
args.Cancel= true;
}
}
}private void Popup_PopupClosed(objectsender, RadPopupClosedEventArgs args)
{if(isInnerCallHide)
{return;
}this.IsPopupOpen = false;this.SwitchArrowState(false);
}private voidCreateArrow()
{this.arrow = newRadArrowButtonElement()
{
ClickMode=ClickMode.Press,
MinSize= newSize(SystemInformation.VerticalScrollBarWidth,
RadArrowButtonElement.RadArrowButtonDefaultSize.Height),
StretchHorizontally= false,
StretchVertically= true,
Margin= new System.Windows.Forms.Padding(2),
};
arrow.Fill.NumberOfColors= 1;
arrow.Fill.BackColor=ARROW_NORMAL_BG_COLOR;
arrow.Border.BoxStyle=BorderBoxStyle.SingleBorder;
arrow.Border.GradientStyle=GradientStyles.Solid;
arrow.Border.ForeColor=ARROW_BORDER_COLOR;
arrow.RadPropertyChanged+=Arrow_RadPropertyChanged;
arrow.Click+=Arrow_Click;
}private void Arrow_Click(objectsender, EventArgs e)
{if (this.IsPopupOpen)
{this.IsPopupOpen = false;this.SwitchArrowState(false);this.HidePopup();
}else{this.IsPopupOpen = true;this.SwitchArrowState(true);this.ShowPopup();
}
}private voidHidePopup()
{this.isInnerCallHide = true;this.popup.Hide();this.isInnerCallHide = false;
}private voidShowPopup()
{this.popup.Width = this.Bounds.Width;this.popup.Height = 250;this.popup.ShowPopup(this.RectangleToScreen(this.ControlBoundingRectangle));
}private void SwitchArrowState(boolisPressed)
{this.arrow.Fill.BackColor = isPressed ?ARROW_PRESSED_BG_COLOR :
(arrow.IsMouseOver?ARROW_MOUSE_OVER_BG_COLOR : ARROW_NORMAL_BG_COLOR);
}protected override voidOnPropertyChanged(RadPropertyChangedEventArgs e)
{if (e.Property ==ContainsFocusProperty)
{var isFocus = (bool)e.NewValue;this.BorderWidth = isFocus ?FOCUS_BORDER_WIDTH : NORMAL_BORDER_WIDTH;
}base.OnPropertyChanged(e);
}protected overrideSizeF ArrangeOverride(SizeF finalSize)
{base.ArrangeOverride(finalSize);//arrow on right side float width = this.arrow.DesiredSize.Width;float x = this.RightToLeft ? 0f : (finalSize.Width -width);
RectangleF finalRect= newRectangleF(x, 0f, width, finalSize.Height);this.arrow.Arrange(finalRect);returnfinalSize;
}private void Arrow_RadPropertyChanged(objectsender, RadPropertyChangedEventArgs e)
{if (e.Property ==RadArrowButtonElement.IsMouseOverProperty)
{if (this.IsPopupOpen)
{return;
}var arrow = sender asRadArrowButtonElement;var isMouseOver = (bool)e.NewValue;
arrow.Fill.BackColor= isMouseOver ?ARROW_MOUSE_OVER_BG_COLOR : ARROW_NORMAL_BG_COLOR;
}
}
}public classPopupForm : RadSizablePopupControl
{privateHostTreeView tv;publicPopupForm(RadItem owner)
:base(owner)
{this.SizingMode =SizingMode.UpDownAndRightBottom;this.VerticalAlignmentCorrectionMode =AlignmentCorrectionMode.SnapToOuterEdges;
}publicRadTreeView TreeView
{get{return this.tv.TreeView;
}
}protected override voidCreateChildItems(RadElement parent)
{base.CreateChildItems(parent);this.tv = newHostTreeView();this.tv.TreeView.Focusable = false;this.tv.TreeView.CheckBoxes = true;this.SizingGripDockLayout.Children.Add(tv);
}public override bool OnMouseWheel(Control target, intdelta)
{if (delta < 0)
{this.tv.TreeView.VScrollBar.PerformSmallIncrement(1);
}else{this.tv.TreeView.VScrollBar.PerformSmallDecrement(1);
}return true;
}
}public classHostTreeView : Telerik.WinControls.RadHostItem
{publicHostTreeView()
:base(newRadTreeView())
{
}publicRadTreeView TreeView
{get{return this.HostedControl asRadTreeView;
}
}
}
}
最后说明一点吧，这次封装对于我自己来说还有一个不满意的地方，那就是选择一些项目以后，界面上不显示已经选择的项，希望有人能够完善一下，给出改造后的代码。