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入行已经7,8年了，一直想做一套漂亮点的自定义控件，于是就有了本系列文章。
GitHub：https://github.com/kwwwvagaa/NetWinformControl
码云：https://gitee.com/kwwwvagaa/net_winform_custom_control.git
如果觉得写的还行，请点个 star 支持一下吧
欢迎前来交流探讨： 企鹅群568015492
目录
https://blog.csdn.net/kwwwvagaa/article/details/100586547
准备工作
对原始树控件treeview进行扩展以更改样式
先了解一下我们需要哪些功能，控件ain可以更改整好颜色，行高，选中效果，分割线等
开始
添加组件，命名TreeViewEx 继承TreeView
先看下属性
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("自定义属性"), Description("角标文字字体")]
public Font TipFont
{
get
{
return this._tipFont;
}
set
{
this._tipFont = value;
}
}
[Category("自定义属性"), Description("是否显示角标")]
public Image TipImage
{
get
{
return this._tipImage;
}
set
{
this._tipImage = value;
}
}
[Category("自定义属性"), Description("是否显示角标")]
public bool IsShowTip
{
get
{
return this._isShowTip;
}
set
{
this._isShowTip = value;
}
}
[Category("自定义属性"), Description("使用自定义模式")]
public bool IsShowByCustomModel
{
get
{
return this._isShowByCustomModel;
}
set
{
this._isShowByCustomModel = value;
}
}
[Category("自定义属性"), Description("节点高度（IsShowByCustomModel=true时生效）")]
public int NodeHeight
{
get
{
return this._nodeHeight;
}
set
{
this._nodeHeight = value;
base.ItemHeight = value;
}
}
[Category("自定义属性"), Description("下翻图标（IsShowByCustomModel=true时生效）")]
public Image NodeDownPic
{
get
{
return this._nodeDownPic;
}
set
{
this._nodeDownPic = value;
}
}
[Category("自定义属性"), Description("上翻图标（IsShowByCustomModel=true时生效）")]
public Image NodeUpPic
{
get
{
return this._nodeUpPic;
}
set
{
this._nodeUpPic = value;
}
}
[Category("自定义属性"), Description("节点背景颜色（IsShowByCustomModel=true时生效）")]
public Color NodeBackgroundColor
{
get
{
return this._nodeBackgroundColor;
}
set
{
this._nodeBackgroundColor = value;
}
}
[Category("自定义属性"), Description("节点字体颜色（IsShowByCustomModel=true时生效）")]
public Color NodeForeColor
{
get
{
return this._nodeForeColor;
}
set
{
this._nodeForeColor = value;
}
}
[Category("自定义属性"), Description("节点是否显示分割线（IsShowByCustomModel=true时生效）")]
public bool NodeIsShowSplitLine
{
get
{
return this._nodeIsShowSplitLine;
}
set
{
this._nodeIsShowSplitLine = value;
}
}
[Category("自定义属性"), Description("节点分割线颜色（IsShowByCustomModel=true时生效）")]
public Color NodeSplitLineColor
{
get
{
return this._nodeSplitLineColor;
}
set
{
this._nodeSplitLineColor = value;
}
}
[Category("自定义属性"), Description("选中节点背景颜色（IsShowByCustomModel=true时生效）")]
public Color NodeSelectedColor
{
get
{
return this.m_nodeSelectedColor;
}
set
{
this.m_nodeSelectedColor = value;
}
}
[Category("自定义属性"), Description("选中节点字体颜色（IsShowByCustomModel=true时生效）")]
public Color NodeSelectedForeColor
{
get
{
return this.m_nodeSelectedForeColor;
}
set
{
this.m_nodeSelectedForeColor = value;
}
}
[Category("自定义属性"), Description("父节点是否可选中")]
public bool ParentNodeCanSelect
{
get
{
return this._parentNodeCanSelect;
}
set
{
this._parentNodeCanSelect = value;
}
}样式的更改主要通过节点的重绘，我们使用DrawNode事件来完成
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;
}我们还需要对选中节点时做一些处理
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;
}
}选中后也需要根据属性做相应的操作
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;
}
}主要的东西就这些了，我们看下完成的代码吧
// 版权所有 黄正辉 交流群：568015492 QQ：623128629
// 文件名称：TreeViewEx.cs
// 创建日期：2019-08-15 16:00:55
// 功能描述：TreeView
// 项目地址：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("自定义属性"), Description("角标文字字体")]
public Font TipFont
{
get
{
return this._tipFont;
}
set
{
this._tipFont = value;
}
}
[Category("自定义属性"), Description("是否显示角标")]
public Image TipImage
{
get
{
return this._tipImage;
}
set
{
this._tipImage = value;
}
}
[Category("自定义属性"), Description("是否显示角标")]
public bool IsShowTip
{
get
{
return this._isShowTip;
}
set
{
this._isShowTip = value;
}
}
[Category("自定义属性"), Description("使用自定义模式")]
public bool IsShowByCustomModel
{
get
{
return this._isShowByCustomModel;
}
set
{
this._isShowByCustomModel = value;
}
}
[Category("自定义属性"), Description("节点高度（IsShowByCustomModel=true时生效）")]
public int NodeHeight
{
get
{
return this._nodeHeight;
}
set
{
this._nodeHeight = value;
base.ItemHeight = value;
}
}
[Category("自定义属性"), Description("下翻图标（IsShowByCustomModel=true时生效）")]
public Image NodeDownPic
{
get
{
return this._nodeDownPic;
}
set
{
this._nodeDownPic = value;
}
}
[Category("自定义属性"), Description("上翻图标（IsShowByCustomModel=true时生效）")]
public Image NodeUpPic
{
get
{
return this._nodeUpPic;
}
set
{
this._nodeUpPic = value;
}
}
[Category("自定义属性"), Description("节点背景颜色（IsShowByCustomModel=true时生效）")]
public Color NodeBackgroundColor
{
get
{
return this._nodeBackgroundColor;
}
set
{
this._nodeBackgroundColor = value;
}
}
[Category("自定义属性"), Description("节点字体颜色（IsShowByCustomModel=true时生效）")]
public Color NodeForeColor
{
get
{
return this._nodeForeColor;
}
set
{
this._nodeForeColor = value;
}
}
[Category("自定义属性"), Description("节点是否显示分割线（IsShowByCustomModel=true时生效）")]
public bool NodeIsShowSplitLine
{
get
{
return this._nodeIsShowSplitLine;
}
set
{
this._nodeIsShowSplitLine = value;
}
}
[Category("自定义属性"), Description("节点分割线颜色（IsShowByCustomModel=true时生效）")]
public Color NodeSplitLineColor
{
get
{
return this._nodeSplitLineColor;
}
set
{
this._nodeSplitLineColor = value;
}
}
[Category("自定义属性"), Description("选中节点背景颜色（IsShowByCustomModel=true时生效）")]
public Color NodeSelectedColor
{
get
{
return this.m_nodeSelectedColor;
}
set
{
this.m_nodeSelectedColor = value;
}
}
[Category("自定义属性"), Description("选中节点字体颜色（IsShowByCustomModel=true时生效）")]
public Color NodeSelectedForeColor
{
get
{
return this.m_nodeSelectedForeColor;
}
set
{
this.m_nodeSelectedForeColor = value;
}
}
[Category("自定义属性"), Description("父节点是否可选中")]
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;
}
}
}用处及效果
用处：觉得原始的treeview太难看了，想换一种好看点的风格
效果：
调用示例
for (int i = 0; i < 3; i++)
{
TreeNode tn = new TreeNode(" 父节点" + i);
for (int j = 0; j < 3; j++)
{
tn.Nodes.Add(" 子节点" + j);
}
this.treeViewEx1.Nodes.Add(tn);
}最后的话
如果你喜欢的话，请到 https://gitee.com/kwwwvagaa/net_winform_custom_control 点个星 星吧