（九）C# Winform自定義控件-樹
準(zhǔn)備工作
對原始樹控件treeview進行擴展以更改樣式
先了解一下我們需要哪些功能，控件ain可以更改整好顏色，行高，選中效果，分割線等
開始
添加組件，命名TreeViewEx 繼承TreeView
先看下屬性
private?const?int?WS_VSCROLL?=?2097152;
private?const?int?GWL_STYLE?=?-16;
private?Dictionary<string,?string>?_lstTips?=?new?Dictionary<string,?string>();
private?Font?_tipFont?=?new?Font("Arial?Unicode?MS",?12f);
private?Image?_tipImage?=?Resources.tips;
private?bool?_isShowTip?=?false;
private?bool?_isShowByCustomModel?=?true;
private?int?_nodeHeight?=?50;
private?Image?_nodeDownPic?=?Resources.list_add;
private?Image?_nodeUpPic?=?Resources.list_subtract;
private?Color?_nodeBackgroundColor?=?Color.FromArgb(61,?60,?66);
private?Color?_nodeForeColor?=?Color.White;
private?bool?_nodeIsShowSplitLine?=?false;
private?Color?_nodeSplitLineColor?=?Color.FromArgb(54,?53,?58);
private?Color?m_nodeSelectedColor?=?Color.FromArgb(255,?121,?74);
private?Color?m_nodeSelectedForeColor?=?Color.White;
private?bool?_parentNodeCanSelect?=?true;
private?SizeF?treeFontSize?=?SizeF.Empty;
private?bool?blnHasVBar?=?false;
public?Dictionary<string,?string>?LstTips
{
????get
????{
????????return?this._lstTips;
????}
????set
????{
????????this._lstTips?=?value;
????}
}
[Category("自定義屬性"),?Description("角標(biāo)文字字體")]
public?Font?TipFont
{
????get
????{
????????return?this._tipFont;
????}
????set
????{
????????this._tipFont?=?value;
????}
}
[Category("自定義屬性"),?Description("是否顯示角標(biāo)")]
public?Image?TipImage
{
????get
????{
????????return?this._tipImage;
????}
????set
????{
????????this._tipImage?=?value;
????}
}
[Category("自定義屬性"),?Description("是否顯示角標(biāo)")]
public?bool?IsShowTip
{
????get
????{
????????return?this._isShowTip;
????}
????set
????{
????????this._isShowTip?=?value;
????}
}
[Category("自定義屬性"),?Description("使用自定義模式")]
public?bool?IsShowByCustomModel
{
????get
????{
????????return?this._isShowByCustomModel;
????}
????set
????{
????????this._isShowByCustomModel?=?value;
????}
}
[Category("自定義屬性"),?Description("節(jié)點高度（IsShowByCustomModel=true時生效）")]
public?int?NodeHeight
{
????get
????{
????????return?this._nodeHeight;
????}
????set
????{
????????this._nodeHeight?=?value;
????????base.ItemHeight?=?value;
????}
}
[Category("自定義屬性"),?Description("下翻圖標(biāo)（IsShowByCustomModel=true時生效）")]
public?Image?NodeDownPic
{
????get
????{
????????return?this._nodeDownPic;
????}
????set
????{
????????this._nodeDownPic?=?value;
????}
}
[Category("自定義屬性"),?Description("上翻圖標(biāo)（IsShowByCustomModel=true時生效）")]
public?Image?NodeUpPic
{
????get
????{
????????return?this._nodeUpPic;
????}
????set
????{
????????this._nodeUpPic?=?value;
????}
}
[Category("自定義屬性"),?Description("節(jié)點背景顏色（IsShowByCustomModel=true時生效）")]
public?Color?NodeBackgroundColor
{
????get
????{
????????return?this._nodeBackgroundColor;
????}
????set
????{
????????this._nodeBackgroundColor?=?value;
????}
}
[Category("自定義屬性"),?Description("節(jié)點字體顏色（IsShowByCustomModel=true時生效）")]
public?Color?NodeForeColor
{
????get
????{
????????return?this._nodeForeColor;
????}
????set
????{
????????this._nodeForeColor?=?value;
????}
}
[Category("自定義屬性"),?Description("節(jié)點是否顯示分割線（IsShowByCustomModel=true時生效）")]
public?bool?NodeIsShowSplitLine
{
????get
????{
????????return?this._nodeIsShowSplitLine;
????}
????set
????{
????????this._nodeIsShowSplitLine?=?value;
????}
}
[Category("自定義屬性"),?Description("節(jié)點分割線顏色（IsShowByCustomModel=true時生效）")]
public?Color?NodeSplitLineColor
{
????get
????{
????????return?this._nodeSplitLineColor;
????}
????set
????{
????????this._nodeSplitLineColor?=?value;
????}
}
[Category("自定義屬性"),?Description("選中節(jié)點背景顏色（IsShowByCustomModel=true時生效）")]
public?Color?NodeSelectedColor
{
????get
????{
????????return?this.m_nodeSelectedColor;
????}
????set
????{
????????this.m_nodeSelectedColor?=?value;
????}
}
[Category("自定義屬性"),?Description("選中節(jié)點字體顏色（IsShowByCustomModel=true時生效）")]
public?Color?NodeSelectedForeColor
{
????get
????{
????????return?this.m_nodeSelectedForeColor;
????}
????set
????{
????????this.m_nodeSelectedForeColor?=?value;
????}
}
[Category("自定義屬性"),?Description("父節(jié)點是否可選中")]
public?bool?ParentNodeCanSelect
{
????get
????{
????????return?this._parentNodeCanSelect;
????}
????set
????{
????????this._parentNodeCanSelect?=?value;
????}
}
樣式的更改主要通過節(jié)點的重繪，我們使用DrawNode事件來完成
base.DrawNode?+=?new?DrawTreeNodeEventHandler(this.treeview_DrawNode);
private?void?treeview_DrawNode(object?sender,?DrawTreeNodeEventArgs?e)
{
????try
????{
????????if?(e.Node?==?null?||?!this._isShowByCustomModel?||?(e.Node.Bounds.Width?<=?0?&&?e.Node.Bounds.Height?<=?0?&&?e.Node.Bounds.X?<=?0?&&?e.Node.Bounds.Y?<=?0))
????????{
????????????e.DrawDefault?=?true;
????????}
????????else
????????{
????????????if?(base.Nodes.IndexOf(e.Node)?==?0)
????????????{
????????????????this.blnHasVBar?=?this.IsVerticalScrollBarVisible();
????????????}
????????????Font?font?=?e.Node.NodeFont;
????????????if?(font?==?null)
????????????{
????????????????font?=?((TreeView)sender).Font;
????????????}
????????????if?(this.treeFontSize?==?SizeF.Empty)
????????????{
????????????????this.treeFontSize?=?this.GetFontSize(font,?e.Graphics);
????????????}
????????????bool?flag?=?false;
????????????int?num?=?0;
????????????if?(base.ImageList?!=?null?&&?base.ImageList.Images.Count?>?0?&&?e.Node.ImageIndex?>=?0?&&?e.Node.ImageIndex?base.ImageList.Images.Count)
????????????{
????????????????flag?=?true;
????????????????num?=?(e.Bounds.Height?-?base.ImageList.ImageSize.Height)?/?2;
????????????}
????????????if?((e.State?==?TreeNodeStates.Selected?||?e.State?==?TreeNodeStates.Focused?||?e.State?==?(TreeNodeStates.Focused?|?TreeNodeStates.Selected))?&&?(this._parentNodeCanSelect?||?e.Node.Nodes.Count?<=?0))
????????????{
????????????????e.Graphics.FillRectangle(new?SolidBrush(this.m_nodeSelectedColor),?new?Rectangle(new?Point(0,?e.Node.Bounds.Y),?new?Size(base.Width,?e.Node.Bounds.Height)));
????????????????e.Graphics.DrawString(e.Node.Text,?font,?new?SolidBrush(this.m_nodeSelectedForeColor),?(float)e.Bounds.X,?(float)e.Bounds.Y?+?((float)this._nodeHeight?-?this.treeFontSize.Height)?/?2f);
????????????}
????????????else
????????????{
????????????????e.Graphics.FillRectangle(new?SolidBrush(this._nodeBackgroundColor),?new?Rectangle(new?Point(0,?e.Node.Bounds.Y),?new?Size(base.Width,?e.Node.Bounds.Height)));
????????????????e.Graphics.DrawString(e.Node.Text,?font,?new?SolidBrush(this._nodeForeColor),?(float)e.Bounds.X,?(float)e.Bounds.Y?+?((float)this._nodeHeight?-?this.treeFontSize.Height)?/?2f);
????????????}
????????????if?(flag)
????????????{
????????????????int?num2?=?e.Bounds.X?-?num?-?base.ImageList.ImageSize.Width;
????????????????if?(num2?0)
????????????????{
????????????????????num2?=?3;
????????????????}
????????????????e.Graphics.DrawImage(base.ImageList.Images[e.Node.ImageIndex],?new?Rectangle(new?Point(num2,?e.Bounds.Y?+?num),?base.ImageList.ImageSize));
????????????}
????????????if?(this._nodeIsShowSplitLine)
????????????{
????????????????e.Graphics.DrawLine(new?Pen(this._nodeSplitLineColor,?1f),?new?Point(0,?e.Bounds.Y?+?this._nodeHeight?-?1),?new?Point(base.Width,?e.Bounds.Y?+?this._nodeHeight?-?1));
????????????}
????????????bool?flag2?=?false;
????????????if?(e.Node.Nodes.Count?>?0)
????????????{
????????????????if?(e.Node.IsExpanded?&&?this._nodeUpPic?!=?null)
????????????????{
????????????????????e.Graphics.DrawImage(this._nodeUpPic,?new?Rectangle(base.Width?-?(this.blnHasVBar???50?:?30),?e.Bounds.Y?+?(this._nodeHeight?-?20)?/?2,?20,?20));
????????????????}
????????????????else?if?(this._nodeDownPic?!=?null)
????????????????{
????????????????????e.Graphics.DrawImage(this._nodeDownPic,?new?Rectangle(base.Width?-?(this.blnHasVBar???50?:?30),?e.Bounds.Y?+?(this._nodeHeight?-?20)?/?2,?20,?20));
????????????????}
????????????????flag2?=?true;
????????????}
????????????if?(this._isShowTip?&&?this._lstTips.ContainsKey(e.Node.Name)?&&?!string.IsNullOrWhiteSpace(this._lstTips[e.Node.Name]))
????????????{
????????????????int?num3?=?base.Width?-?(this.blnHasVBar???50?:?30)?-?(flag2???20?:?0);
????????????????int?num4?=?e.Bounds.Y?+?(this._nodeHeight?-?20)?/?2;
????????????????e.Graphics.DrawImage(this._tipImage,?new?Rectangle(num3,?num4,?20,?20));
????????????????SizeF?sizeF?=?e.Graphics.MeasureString(this._lstTips[e.Node.Name],?this._tipFont,?100,?StringFormat.GenericTypographic);
????????????????e.Graphics.DrawString(this._lstTips[e.Node.Name],?this._tipFont,?new?SolidBrush(Color.White),?(float)(num3?+?10)?-?sizeF.Width?/?2f?-?3f,?(float)(num4?+?10)?-?sizeF.Height?/?2f);
????????????}
????????}
????}
????catch?(Exception?ex)
????{
????????throw?ex;
????}
}
private?SizeF?GetFontSize(Font?font,?Graphics?g?=?null)
{
????SizeF?result;
????try
????{
????????bool?flag?=?false;
????????if?(g?==?null)
????????{
????????????g?=?base.CreateGraphics();
????????????flag?=?true;
????????}
????????SizeF?sizeF?=?g.MeasureString("a",?font,?100,?StringFormat.GenericTypographic);
????????if?(flag)
????????{
????????????g.Dispose();
????????}
????????result?=?sizeF;
????}
????catch?(Exception?ex)
????{
????????throw?ex;
????}
????return?result;
}
[DllImport("user32",?CharSet?=?CharSet.Auto)]
private?static?extern?int?GetWindowLong(IntPtr?hwnd,?int?nIndex);
private?bool?IsVerticalScrollBarVisible()
{
????return?base.IsHandleCreated?&&?(TreeViewEx.GetWindowLong(base.Handle,?-16)?&?2097152)?!=?0;
}
我們還需要對選中節(jié)點時做一些處理
private?void?TreeViewEx_NodeMouseClick(object?sender,?TreeNodeMouseClickEventArgs?e)
{
????try
????{
????????if?(e.Node?!=?null)
????????{
????????????if?(e.Node.Nodes.Count?>?0)
????????????{
????????????????if?(e.Node.IsExpanded)
????????????????{
????????????????????e.Node.Collapse();
????????????????}
????????????????else
????????????????{
????????????????????e.Node.Expand();
????????????????}
????????????}
????????????if?(base.SelectedNode?!=?null)
????????????{
????????????????if?(base.SelectedNode?==?e.Node?&&?e.Node.IsExpanded)
????????????????{
????????????????????if?(!this._parentNodeCanSelect)
????????????????????{
????????????????????????if?(e.Node.Nodes.Count?>?0)
????????????????????????{
????????????????????????????base.SelectedNode?=?e.Node.Nodes[0];
????????????????????????}
????????????????????}
????????????????}
????????????}
????????}
????}
????catch?(Exception?ex)
????{
????????throw?ex;
????}
}
選中后也需要根據(jù)屬性做相應(yīng)的操作
private?void?TreeViewEx_AfterSelect(object?sender,?TreeViewEventArgs?e)
{
????try
????{
????????if?(e.Node?!=?null)
????????{
????????????if?(!this._parentNodeCanSelect)
????????????{
????????????????if?(e.Node.Nodes.Count?>?0)
????????????????{
????????????????????e.Node.Expand();
????????????????????base.SelectedNode?=?e.Node.Nodes[0];
????????????????}
????????????}
????????}
????}
????catch?(Exception?ex)
????{
????????throw?ex;
????}
}
主要的東西就這些了，我們看下完成的代碼吧
//?版權(quán)所有??黃正輝??交流群：568015492 ? QQ：623128629
//?文件名稱：TreeViewEx.cs
//?創(chuàng)建日期：2019-08-15 16:00:55
//?功能描述：TreeView
//?項目地址：https://gitee.com/kwwwvagaa/net_winform_custom_control
using?System;
using?System.Collections.Generic;
using?System.ComponentModel;
using?System.Diagnostics;
using?System.Drawing;
using?System.Linq;
using?System.Runtime.InteropServices;
using?System.Text;
using?System.Windows.Forms;
using?HZH_Controls.Properties;
namespace?HZH_Controls.Controls
{
???public?partial?class?TreeViewEx?:?TreeView
???{
???????private?const?int?WS_VSCROLL?=?2097152;
???????private?const?int?GWL_STYLE?=?-16;
???????private?Dictionary<string,?string>?_lstTips?=?new?Dictionary<string,?string>();
???????private?Font?_tipFont?=?new?Font("Arial?Unicode?MS",?12f);
???????private?Image?_tipImage?=?Resources.tips;
???????private?bool?_isShowTip?=?false;
???????private?bool?_isShowByCustomModel?=?true;
???????private?int?_nodeHeight?=?50;
???????private?Image?_nodeDownPic?=?Resources.list_add;
???????private?Image?_nodeUpPic?=?Resources.list_subtract;
???????private?Color?_nodeBackgroundColor?=?Color.FromArgb(61,?60,?66);
???????private?Color?_nodeForeColor?=?Color.White;
???????private?bool?_nodeIsShowSplitLine?=?false;
???????private?Color?_nodeSplitLineColor?=?Color.FromArgb(54,?53,?58);
???????private?Color?m_nodeSelectedColor?=?Color.FromArgb(255,?121,?74);
???????private?Color?m_nodeSelectedForeColor?=?Color.White;
???????private?bool?_parentNodeCanSelect?=?true;
???????private?SizeF?treeFontSize?=?SizeF.Empty;
???????private?bool?blnHasVBar?=?false;
???????public?Dictionary<string,?string>?LstTips
???????{
???????????get
???????????{
???????????????return?this._lstTips;
???????????}
???????????set
???????????{
???????????????this._lstTips?=?value;
???????????}
???????}
???????[Category("自定義屬性"),?Description("角標(biāo)文字字體")]
???????public?Font?TipFont
???????{
???????????get
???????????{
???????????????return?this._tipFont;
???????????}
???????????set
???????????{
???????????????this._tipFont?=?value;
???????????}
???????}
???????[Category("自定義屬性"),?Description("是否顯示角標(biāo)")]
???????public?Image?TipImage
???????{
???????????get
???????????{
???????????????return?this._tipImage;
???????????}
???????????set
???????????{
???????????????this._tipImage?=?value;
???????????}
???????}
???????[Category("自定義屬性"),?Description("是否顯示角標(biāo)")]
???????public?bool?IsShowTip
???????{
???????????get
???????????{
???????????????return?this._isShowTip;
???????????}
???????????set
???????????{
???????????????this._isShowTip?=?value;
???????????}
???????}
???????[Category("自定義屬性"),?Description("使用自定義模式")]
???????public?bool?IsShowByCustomModel
???????{
???????????get
???????????{
???????????????return?this._isShowByCustomModel;
???????????}
???????????set
???????????{
???????????????this._isShowByCustomModel?=?value;
???????????}
???????}
???????[Category("自定義屬性"),?Description("節(jié)點高度（IsShowByCustomModel=true時生效）")]
???????public?int?NodeHeight
???????{
???????????get
???????????{
???????????????return?this._nodeHeight;
???????????}
???????????set
???????????{
???????????????this._nodeHeight?=?value;
???????????????base.ItemHeight?=?value;
???????????}
???????}
???????[Category("自定義屬性"),?Description("下翻圖標(biāo)（IsShowByCustomModel=true時生效）")]
???????public?Image?NodeDownPic
???????{
???????????get
???????????{
???????????????return?this._nodeDownPic;
???????????}
???????????set
???????????{
???????????????this._nodeDownPic?=?value;
???????????}
???????}
???????[Category("自定義屬性"),?Description("上翻圖標(biāo)（IsShowByCustomModel=true時生效）")]
???????public?Image?NodeUpPic
???????{
???????????get
???????????{
???????????????return?this._nodeUpPic;
???????????}
???????????set
???????????{
???????????????this._nodeUpPic?=?value;
???????????}
???????}
???????[Category("自定義屬性"),?Description("節(jié)點背景顏色（IsShowByCustomModel=true時生效）")]
???????public?Color?NodeBackgroundColor
???????{
???????????get
???????????{
???????????????return?this._nodeBackgroundColor;
???????????}
???????????set
???????????{
???????????????this._nodeBackgroundColor?=?value;
???????????}
???????}
???????[Category("自定義屬性"),?Description("節(jié)點字體顏色（IsShowByCustomModel=true時生效）")]
???????public?Color?NodeForeColor
???????{
???????????get
???????????{
???????????????return?this._nodeForeColor;
???????????}
???????????set
???????????{
???????????????this._nodeForeColor?=?value;
???????????}
???????}
???????[Category("自定義屬性"),?Description("節(jié)點是否顯示分割線（IsShowByCustomModel=true時生效）")]
???????public?bool?NodeIsShowSplitLine
???????{
???????????get
???????????{
???????????????return?this._nodeIsShowSplitLine;
???????????}
???????????set
???????????{
???????????????this._nodeIsShowSplitLine?=?value;
???????????}
???????}
???????[Category("自定義屬性"),?Description("節(jié)點分割線顏色（IsShowByCustomModel=true時生效）")]
???????public?Color?NodeSplitLineColor
???????{
???????????get
???????????{
???????????????return?this._nodeSplitLineColor;
???????????}
???????????set
???????????{
???????????????this._nodeSplitLineColor?=?value;
???????????}
???????}
???????[Category("自定義屬性"),?Description("選中節(jié)點背景顏色（IsShowByCustomModel=true時生效）")]
???????public?Color?NodeSelectedColor
???????{
???????????get
???????????{
???????????????return?this.m_nodeSelectedColor;
???????????}
???????????set
???????????{
???????????????this.m_nodeSelectedColor?=?value;
???????????}
???????}
???????[Category("自定義屬性"),?Description("選中節(jié)點字體顏色（IsShowByCustomModel=true時生效）")]
???????public?Color?NodeSelectedForeColor
???????{
???????????get
???????????{
???????????????return?this.m_nodeSelectedForeColor;
???????????}
???????????set
???????????{
???????????????this.m_nodeSelectedForeColor?=?value;
???????????}
???????}
???????[Category("自定義屬性"),?Description("父節(jié)點是否可選中")]
???????public?bool?ParentNodeCanSelect
???????{
???????????get
???????????{
???????????????return?this._parentNodeCanSelect;
???????????}
???????????set
???????????{
???????????????this._parentNodeCanSelect?=?value;
???????????}
???????}
???????public?TreeViewEx()
???????{
???????????base.HideSelection?=?false;
???????????base.DrawMode?=?TreeViewDrawMode.OwnerDrawAll;
???????????base.DrawNode?+=?new?DrawTreeNodeEventHandler(this.treeview_DrawNode);
???????????base.NodeMouseClick?+=?new?TreeNodeMouseClickEventHandler(this.TreeViewEx_NodeMouseClick);
???????????base.SizeChanged?+=?new?EventHandler(this.TreeViewEx_SizeChanged);
???????????base.AfterSelect?+=?new?TreeViewEventHandler(this.TreeViewEx_AfterSelect);
???????????base.FullRowSelect?=?true;
???????????base.ShowLines?=?false;
???????????base.ShowPlusMinus?=?false;
???????????base.ShowRootLines?=?false;
???????????this.BackColor?=?Color.FromArgb(61,?60,?66);
???????????DoubleBuffered?=?true;
???????}
???????protected?override?void?WndProc(ref?Message?m)
???????{
???????????if?(m.Msg?==?0x0014)?//?禁掉清除背景消息WM_ERASEBKGND
???????????????return;
???????????base.WndProc(ref?m);
???????}
???????private?void?TreeViewEx_AfterSelect(object?sender,?TreeViewEventArgs?e)
???????{
???????????try
???????????{
???????????????if?(e.Node?!=?null)
???????????????{
???????????????????if?(!this._parentNodeCanSelect)
???????????????????{
???????????????????????if?(e.Node.Nodes.Count?>?0)
???????????????????????{
???????????????????????????e.Node.Expand();
???????????????????????????base.SelectedNode?=?e.Node.Nodes[0];
???????????????????????}
???????????????????}
???????????????}
???????????}
???????????catch?(Exception?ex)
???????????{
???????????????throw?ex;
???????????}
???????}
???????private?void?TreeViewEx_SizeChanged(object?sender,?EventArgs?e)
???????{
???????????this.Refresh();
???????}
???????private?void?TreeViewEx_NodeMouseClick(object?sender,?TreeNodeMouseClickEventArgs?e)
???????{
???????????try
???????????{
???????????????if?(e.Node?!=?null)
???????????????{
???????????????????if?(e.Node.Nodes.Count?>?0)
???????????????????{
???????????????????????if?(e.Node.IsExpanded)
???????????????????????{
???????????????????????????e.Node.Collapse();
???????????????????????}
???????????????????????else
???????????????????????{
???????????????????????????e.Node.Expand();
???????????????????????}
???????????????????}
???????????????????if?(base.SelectedNode?!=?null)
???????????????????{
???????????????????????if?(base.SelectedNode?==?e.Node?&&?e.Node.IsExpanded)
???????????????????????{
???????????????????????????if?(!this._parentNodeCanSelect)
???????????????????????????{
???????????????????????????????if?(e.Node.Nodes.Count?>?0)
???????????????????????????????{
???????????????????????????????????base.SelectedNode?=?e.Node.Nodes[0];
???????????????????????????????}
???????????????????????????}
???????????????????????}
???????????????????}
???????????????}
???????????}
???????????catch?(Exception?ex)
???????????{
???????????????throw?ex;
???????????}
???????}
???????private?void?treeview_DrawNode(object?sender,?DrawTreeNodeEventArgs?e)
???????{
???????????try
???????????{
???????????????if?(e.Node?==?null?||?!this._isShowByCustomModel?||?(e.Node.Bounds.Width?<=?0?&&?e.Node.Bounds.Height?<=?0?&&?e.Node.Bounds.X?<=?0?&&?e.Node.Bounds.Y?<=?0))
???????????????{
???????????????????e.DrawDefault?=?true;
???????????????}
???????????????else
???????????????{
???????????????????if?(base.Nodes.IndexOf(e.Node)?==?0)
???????????????????{
???????????????????????this.blnHasVBar?=?this.IsVerticalScrollBarVisible();
???????????????????}
???????????????????Font?font?=?e.Node.NodeFont;
???????????????????if?(font?==?null)
???????????????????{
???????????????????????font?=?((TreeView)sender).Font;
???????????????????}
???????????????????if?(this.treeFontSize?==?SizeF.Empty)
???????????????????{
???????????????????????this.treeFontSize?=?this.GetFontSize(font,?e.Graphics);
???????????????????}
???????????????????bool?flag?=?false;
???????????????????int?num?=?0;
???????????????????if?(base.ImageList?!=?null?&&?base.ImageList.Images.Count?>?0?&&?e.Node.ImageIndex?>=?0?&&?e.Node.ImageIndex?base.ImageList.Images.Count)
???????????????????{
???????????????????????flag?=?true;
???????????????????????num?=?(e.Bounds.Height?-?base.ImageList.ImageSize.Height)?/?2;
???????????????????}
???????????????????if?((e.State?==?TreeNodeStates.Selected?||?e.State?==?TreeNodeStates.Focused?||?e.State?==?(TreeNodeStates.Focused?|?TreeNodeStates.Selected))?&&?(this._parentNodeCanSelect?||?e.Node.Nodes.Count?<=?0))
???????????????????{
???????????????????????e.Graphics.FillRectangle(new?SolidBrush(this.m_nodeSelectedColor),?new?Rectangle(new?Point(0,?e.Node.Bounds.Y),?new?Size(base.Width,?e.Node.Bounds.Height)));
???????????????????????e.Graphics.DrawString(e.Node.Text,?font,?new?SolidBrush(this.m_nodeSelectedForeColor),?(float)e.Bounds.X,?(float)e.Bounds.Y?+?((float)this._nodeHeight?-?this.treeFontSize.Height)?/?2f);
???????????????????}
???????????????????else
???????????????????{
???????????????????????e.Graphics.FillRectangle(new?SolidBrush(this._nodeBackgroundColor),?new?Rectangle(new?Point(0,?e.Node.Bounds.Y),?new?Size(base.Width,?e.Node.Bounds.Height)));
???????????????????????e.Graphics.DrawString(e.Node.Text,?font,?new?SolidBrush(this._nodeForeColor),?(float)e.Bounds.X,?(float)e.Bounds.Y?+?((float)this._nodeHeight?-?this.treeFontSize.Height)?/?2f);
???????????????????}
???????????????????if?(flag)
???????????????????{
???????????????????????int?num2?=?e.Bounds.X?-?num?-?base.ImageList.ImageSize.Width;
???????????????????????if?(num2?0)
???????????????????????{
???????????????????????????num2?=?3;
???????????????????????}
???????????????????????e.Graphics.DrawImage(base.ImageList.Images[e.Node.ImageIndex],?new?Rectangle(new?Point(num2,?e.Bounds.Y?+?num),?base.ImageList.ImageSize));
???????????????????}
???????????????????if?(this._nodeIsShowSplitLine)
???????????????????{
???????????????????????e.Graphics.DrawLine(new?Pen(this._nodeSplitLineColor,?1f),?new?Point(0,?e.Bounds.Y?+?this._nodeHeight?-?1),?new?Point(base.Width,?e.Bounds.Y?+?this._nodeHeight?-?1));
???????????????????}
???????????????????bool?flag2?=?false;
???????????????????if?(e.Node.Nodes.Count?>?0)
???????????????????{
???????????????????????if?(e.Node.IsExpanded?&&?this._nodeUpPic?!=?null)
???????????????????????{
???????????????????????????e.Graphics.DrawImage(this._nodeUpPic,?new?Rectangle(base.Width?-?(this.blnHasVBar???50?:?30),?e.Bounds.Y?+?(this._nodeHeight?-?20)?/?2,?20,?20));
???????????????????????}
???????????????????????else?if?(this._nodeDownPic?!=?null)
???????????????????????{
???????????????????????????e.Graphics.DrawImage(this._nodeDownPic,?new?Rectangle(base.Width?-?(this.blnHasVBar???50?:?30),?e.Bounds.Y?+?(this._nodeHeight?-?20)?/?2,?20,?20));
???????????????????????}
???????????????????????flag2?=?true;
???????????????????}
???????????????????if?(this._isShowTip?&&?this._lstTips.ContainsKey(e.Node.Name)?&&?!string.IsNullOrWhiteSpace(this._lstTips[e.Node.Name]))
???????????????????{
???????????????????????int?num3?=?base.Width?-?(this.blnHasVBar???50?:?30)?-?(flag2???20?:?0);
???????????????????????int?num4?=?e.Bounds.Y?+?(this._nodeHeight?-?20)?/?2;
???????????????????????e.Graphics.DrawImage(this._tipImage,?new?Rectangle(num3,?num4,?20,?20));
???????????????????????SizeF?sizeF?=?e.Graphics.MeasureString(this._lstTips[e.Node.Name],?this._tipFont,?100,?StringFormat.GenericTypographic);
???????????????????????e.Graphics.DrawString(this._lstTips[e.Node.Name],?this._tipFont,?new?SolidBrush(Color.White),?(float)(num3?+?10)?-?sizeF.Width?/?2f?-?3f,?(float)(num4?+?10)?-?sizeF.Height?/?2f);
???????????????????}
???????????????}
???????????}
???????????catch?(Exception?ex)
???????????{
???????????????throw?ex;
???????????}
???????}
???????private?SizeF?GetFontSize(Font?font,?Graphics?g?=?null)
???????{
???????????SizeF?result;
???????????try
???????????{
???????????????bool?flag?=?false;
???????????????if?(g?==?null)
???????????????{
???????????????????g?=?base.CreateGraphics();
???????????????????flag?=?true;
???????????????}
???????????????SizeF?sizeF?=?g.MeasureString("a",?font,?100,?StringFormat.GenericTypographic);
???????????????if?(flag)
???????????????{
???????????????????g.Dispose();
???????????????}
???????????????result?=?sizeF;
???????????}
???????????catch?(Exception?ex)
???????????{
???????????????throw?ex;
???????????}
???????????return?result;
???????}
???????[DllImport("user32",?CharSet?=?CharSet.Auto)]
???????private?static?extern?int?GetWindowLong(IntPtr?hwnd,?int?nIndex);
???????private?bool?IsVerticalScrollBarVisible()
???????{
???????????return?base.IsHandleCreated?&&?(TreeViewEx.GetWindowLong(base.Handle,?-16)?&?2097152)?!=?0;
???????}
???}
}
用處及效果
用處：覺得原始的treeview太難看了，想換一種好看點的風(fēng)格
效果：
調(diào)用示例
for?(int?i?=?0;?i?3;?i++)
{
????TreeNode?tn?=?new?TreeNode("??父節(jié)點"?+?i);
????for?(int?j?=?0;?j?3;?j++)
????{
????????tn.Nodes.Add("????子節(jié)點"?+?j);
????}
????this.treeViewEx1.Nodes.Add(tn);
}
最后的話
如果你喜歡的話，請到 https://gitee.com/kwwwvagaa/net_winform_custom_control 點個星星吧，另本站轉(zhuǎn)載地址：https://dotnet9.com/5316.html。
作者：冰封一夏 出處：http://www.hzhcontrols.com/doc.html 本文版權(quán)歸作者所有，歡迎轉(zhuǎn)載，但未經(jīng)作者同意必須保留此段聲明， 且在文章頁面明顯位置給出原文連接，否則保留追究法律責(zé)任的權(quán)利。 GitHub：https://github.com/kwwwvagaa/NetWinformControl 碼云：https://gitee.com/kwwwvagaa/net_winform_custom_control.git
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