C# TreeView 自定义显示checkbox

本项目需要对TreeView进行定制，要求比较简单，主要要求如下：

Winform中TreeView控件默认只支持所有级别的CheckBox显示或者不显示，不能控制制定Level的树节点显示

效果如下：

效果实现代码：

(1)属性和事件设置

this.treeViewGroupStatements.CheckBoxes = true;
this.treeViewGroupStatements.DrawMode = TreeViewDrawMode.OwnerDrawAll;
this.treeViewGroupStatements.DrawNode+=new DrawTreeNodeEventHandler(treeViewGroupStatements_DrawNode);

(2)实现代码

#region 隐藏CheckBoxs
 //要隐藏的TreeNode的level
public ArrayList HideLevelList = new ArrayList() { 0, 1 };
private void treeViewGroupStatements_DrawNode(object sender, DrawTreeNodeEventArgs e)
{
    HideLevelOfTreeView(e.Node);
    e.DrawDefault = true;
 
}
private void HideLevelOfTreeView(TreeNode tn)
{
    //控制这个条件可以自定义显示checkbox的条件
    if (HideLevelList.Contains(tn.Level))
        HideCheckBox(tn.TreeView, tn);
}
 
//#endregion
 
 
private const int TVIF_STATE = 0x8;
private const int TVIS_STATEIMAGEMASK = 0xF000;
private const int TV_FIRST = 0x1100;
private const int TVM_SETITEM = TV_FIRST + 63;
private void HideCheckBox(TreeView tvw, TreeNode node)
{
 
    TVITEM tvi = new TVITEM();
 
    tvi.hItem = node.Handle;
 
    tvi.mask = TVIF_STATE;
 
    tvi.stateMask = TVIS_STATEIMAGEMASK;
 
    tvi.state = 0;
 
    SendMessage(tvw.Handle, TVM_SETITEM, IntPtr.Zero, ref tvi);
 
}
 
[StructLayout(LayoutKind.Sequential, Pack = 8, CharSet = CharSet.Auto)]
 
private struct TVITEM
{
    public int mask;
    public IntPtr hItem;
    public int state;
    public int stateMask;
    [MarshalAs(UnmanagedType.LPTStr)]
    public string lpszText;
    public int cchTextMax;
    public int iImage;
    public int iSelectedImage; public int cChildren; public IntPtr lParam;
}
 
[DllImport("user32.dll", CharSet = CharSet.Auto)]
private static extern IntPtr SendMessage(IntPtr hWnd, int Msg, IntPtr wParam, ref TVITEM lParam);
#endregion