using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace treeview
{
public partial class Form_TreeView : Form
{
int treeViewLocationY = 0;//定高变量
int moveDistance = 0 , moveArea = 0; //移动参数
int B_Height = 0 , H_Height = 0; //滑动条高度
int one_Nodes = 0, two_Nodes = 0, three_Nodes = 0, four_Nodes = 0;//节点数
bool mouse_Press = false; //鼠标按下
bool mouse_Wheel = false; //滑轮是否滚动
Point mouseOff; //存放当前鼠标位置
Point treeViewLocation; //初始位置
public Form_TreeView()
{
InitializeComponent();
treeViewLocation = this.treeView.Location;
B_Height = ScrollBar_panel.Height;
ScrollHard_panel.Location = new Point(0, 0);
Set_Scroll();
//鼠标事件
ScrollHard_panel.MouseWheel += new MouseEventHandler(OnMouseWheel);
ScrollHard_panel.MouseDown += new MouseEventHandler(ScrollHard_panel_MouseDown);
ScrollHard_panel.MouseUp += new MouseEventHandler(ScrollHard_panel_MouseUp);
ScrollHard_panel.MouseMove += new MouseEventHandler(ScrollHard_panel_MouseMove);
ScrollHard_panel.MouseLeave += ScrollHard_panel_MouseLeave;
timer1.Start();
}
//鼠标按下
private void ScrollHard_panel_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == MouseButtons.Left) //鼠标左键
{
treeViewLocationY = this.treeView.Location.Y;
mouseOff.Y = e.Y; //取当前位置
mouse_Press = true; //鼠标按下
}
}
//鼠标放开
private void ScrollHard_panel_MouseUp(object sender, MouseEventArgs e)
{
mouse_Press = false; //鼠标放开
}
//鼠标离开范围
private void ScrollHard_panel_MouseLeave(object sender, EventArgs e)
{
mouse_Wheel = false; //滑轮不可用
}
//鼠标移动事件
private void ScrollHard_panel_MouseMove(object sender, MouseEventArgs e)
{
mouse_Wheel = true; //可以用滑轮
if (mouse_Press) //鼠标按下状态
{
int set_y = ScrollHard_panel.Top + e.Y - mouseOff.Y;
if (set_y < 0) { set_y = 0; } //超范围
else if (set_y > moveArea) { set_y = moveArea; } //超范围
else { ScrollHard_panel.Location = new Point(ScrollHard_panel.Location.X, set_y); } //滚动块的定位
float num = (e.Y - mouseOff.Y) / (float)moveArea * (treeView.Height - ScrollBar_panel.Height);
if (ScrollHard_panel.Location.Y <= 1)
{
treeView.Location = treeViewLocation;
}
else if (ScrollHard_panel.Location.Y >= moveArea-1)
{
treeView.Location = new Point(this.treeView.Location.X, -(treeView.Height - ScrollBar_panel.Height));
}
else
{
treeView.Location = new Point(treeView.Location.X, this.treeView.Location.Y - (int)num);
}
}
}
//定位TreeView
private void TreeViewLocation()
{
if (ScrollHard_panel.Location.Y <= 1)
{
treeView.Location = treeViewLocation;
}
else if (ScrollHard_panel.Location.Y >= moveArea - 1)
{
treeView.Location = new Point(treeView.Location.X, -(treeView.Height - ScrollBar_panel.Height));
}
else
{
treeView.Location = new Point(treeView.Location.X, treeViewLocationY - moveDistance);
}
}
//鼠标滑轮事件
private void OnMouseWheel(object sender, System.Windows.Forms.MouseEventArgs e)
{
int set_y = 0;
if (mouse_Wheel) //是否判断鼠标滑轮
{
if (e.Delta > 0) //滑轮向上
{
set_y = ScrollHard_panel.Location.Y - 10; //每次移动10
if (set_y < 0) { set_y = 0; } //超范围
}
if (e.Delta < 0) //滑轮向下
{
set_y = ScrollHard_panel.Location.Y + 10; //每次移动10
if (set_y > moveArea) { set_y = moveArea; } //超范围
}
ScrollHard_panel.Location = new Point(0, set_y); //滚动块的定位
moveDistance = (int)(set_y / (float)moveArea * (treeView.Height - ScrollBar_panel.Height));
TreeViewLocation();
}
}
private void top_btn_Click(object sender, EventArgs e)
{
int set_y = ScrollHard_panel.Location.Y - 10; //每次移动10
if (set_y < 0) { set_y = 0; } //超范围
ScrollHard_panel.Location = new Point(0, set_y); //滚动块的定位
moveDistance = (int)(set_y / (float)moveArea * (treeView.Height - ScrollBar_panel.Height));
TreeViewLocation();
}
private void down_btn_Click(object sender, EventArgs e)
{
int set_y = ScrollHard_panel.Location.Y + 10; //每次移动10
if (set_y > moveArea) { set_y = moveArea; } //超范围
ScrollHard_panel.Location = new Point(0, set_y); //滚动块的定位
moveDistance = (int)(set_y / (float)moveArea * (treeView.Height - ScrollBar_panel.Height));
TreeViewLocation();
}
//建立滚动控件
private void Set_Scroll()
{
H_Height = B_Height * B_Height / GetNodesHeight();
if (H_Height >= B_Height)
{
ScrollHard_panel.Visible = false;
ScrollBar_panel.Visible = false;
}
else
{
ScrollHard_panel.Visible = true;
ScrollBar_panel.Visible = true;
ScrollHard_panel.Size = new Size(ScrollBar_panel.Width, H_Height);
}
moveArea = ScrollBar_panel.Height - ScrollHard_panel.Height;
}
//获取treeview动态高度
private int GetNodesHeight()
{
one_Nodes = 0; two_Nodes = 0; three_Nodes = 0; four_Nodes = 0; //归0
one_Nodes = this.treeView.Nodes.Count;
for (int i = 0; i < this.treeView.Nodes.Count; i++)
{
if (this.treeView.Nodes[i].IsExpanded)
{
two_Nodes += this.treeView.Nodes[i].Nodes.Count;
for (int j = 0; j < this.treeView.Nodes[i].Nodes.Count; j++)
{
if (this.treeView.Nodes[i].Nodes[j].IsExpanded)
{
three_Nodes += this.treeView.Nodes[i].Nodes[j].Nodes.Count;
for (int k = 0; k < this.treeView.Nodes[i].Nodes[j].Nodes.Count; k++)
{
if (this.treeView.Nodes[i].Nodes[j].Nodes[k].IsExpanded)
{
four_Nodes += this.treeView.Nodes[i].Nodes[j].Nodes[k].Nodes.Count;
}
}
}
}
}
}
this.treeView.Height = (one_Nodes + two_Nodes + three_Nodes + four_Nodes) * 20;
return this.treeView.Height;
}
//展开节点
private void treeView1_BeforeExpand(object sender, TreeViewCancelEventArgs e)
{
Set_Scroll();
}
//折叠节点
private void treeView1_BeforeCollapse(object sender, TreeViewCancelEventArgs e)
{
Set_Scroll();
}
private void timer1_Tick(object sender, EventArgs e)
{
label1.Text = (treeView.Height - ScrollBar_panel.Height).ToString() + "===" + GetNodesHeight().ToString();
label2.Text = moveDistance.ToString();
label3.Text = one_Nodes + "===" + two_Nodes + "===" + three_Nodes + "===" + four_Nodes;
}
}
｝