开始/EndUpdate（）方法并不是为了消除闪烁而设计的。在EndUpdate（）中出现闪烁是不可避免的，它会重绘控件。它们是为了加速添加大量节点而设计的，这在默认情况下会很慢，因为每一项都会导致重绘。你把它们放在for循环中会使情况变得更糟，把它们移到循环外会立即得到改善。
这可能足以解决您的问题。但您可以做得更好，抑制闪烁需要双缓冲。.NET TreeView类重写DoubleBuffered属性并 * 隐藏 * 它。这是一个历史性的意外，本机Windows控件只在Windows XP和更高版本中支持双缓冲。.NET曾经支持Windows 2000和Windows 98。
现在，这已经不太重要了。您可以通过从TreeView派生自己的类来将其放回原处。向项目中添加一个新类，并粘贴下面所示的代码。编译。将新控件从工具箱顶部拖到窗体上，替换现有的TreeView。效果非常明显，尤其是在滚动时。

using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;

class BufferedTreeView : TreeView {
    protected override void OnHandleCreated(EventArgs e) {
       SendMessage(this.Handle, TVM_SETEXTENDEDSTYLE, (IntPtr)TVS_EX_DOUBLEBUFFER, (IntPtr)TVS_EX_DOUBLEBUFFER);
        base.OnHandleCreated(e);
    }
    // Pinvoke:
    private const int TVM_SETEXTENDEDSTYLE = 0x1100 + 44;
    private const int TVM_GETEXTENDEDSTYLE = 0x1100 + 45;
    private const int TVS_EX_DOUBLEBUFFER = 0x0004;
    [DllImport("user32.dll")]
    private static extern IntPtr SendMessage(IntPtr hWnd, int msg, IntPtr wp, IntPtr lp);
}

如果你和我一样是新手，需要在www.example.com上找到答案vb.net这里是@Hans Passant的答案。我用过了，变化很大

Protected Overrides Sub OnHandleCreated(ByVal e As EventArgs)
    SendMessage(Me.Handle, TVM_SETEXTENDEDSTYLE, CType(TVS_EX_DOUBLEBUFFER, IntPtr), CType(TVS_EX_DOUBLEBUFFER, IntPtr))
    MyBase.OnHandleCreated(e)
End Sub

Private Const TVM_SETEXTENDEDSTYLE As Integer = &H1100 + 44
Private Const TVM_GETEXTENDEDSTYLE As Integer = &H1100 + 45
Private Const TVS_EX_DOUBLEBUFFER As Integer = &H4
<DllImport("user32.dll")>
Private Shared Function SendMessage(ByVal hWnd As IntPtr, ByVal msg As Integer, ByVal wp As IntPtr, ByVal lp As IntPtr) As IntPtr
End Function

并不是绝对需要为此派生一个新类，您也可以编写一个静态类函数，将控件传递给它以启用双缓冲：

public static class Helper
{
    public static void EnableDoubleBuffering(Control control)
    {
         SendMessage(control.Handle, TVM_SETEXTENDEDSTYLE, (IntPtr)TVS_EX_DOUBLEBUFFER, (IntPtr)TVS_EX_DOUBLEBUFFER);
    }
        
    private const int TVM_SETEXTENDEDSTYLE = 0x1100 + 44;
    private const int TVM_GETEXTENDEDSTYLE = 0x1100 + 45;
    private const int TVS_EX_DOUBLEBUFFER = 0x0004;
        
    [DllImport("user32.dll")]
    private static extern IntPtr SendMessage(IntPtr hWnd, int msg, IntPtr wp, IntPtr lp);
}