C# TreeView组件TreeNode节点自动勾选解决方案(TreeViewNodeCheckHander)

  C# TreeView组件TreeNode节点自动勾选解决方案(TreeViewNodeCheckHander)

TreeView 节点自动勾选的场景：

1. 勾选/不勾选父级节点，要同步更新所有子节点的状态

2. 当勾选子节点，父节点必须勾选！

3. 当所有子节点全部勾选，父节点必须是勾选状态

4. 当所有子节点全部不勾选，父节点必须是不勾选状态

TreeViewNodeCheckHander类使用方法：

C# Code:

private void frmSoftwareFunction_Load(object sender, EventArgs e)
{
  
  tv.Nodes.Clear();
  TreeViewNodeCheckHander.Handle(tv);
}


//来源:C/S框架网 | www.csframework.com | QQ:23404761

TreeViewNodeCheckHander类:

C# Code:

/// <summary>
/// TreeView组件TreeNode节点自动勾选几种场景及解决方案
/// </summary>
public class TreeViewNodeCheckHander
{
  public static void Handle(TreeView tv)
  {
    tv.AfterCheck += OnTreeView_AfterCheck;
  }
  
  private static void OnTreeView_AfterCheck(object sender, TreeViewEventArgs e)
  {
    //若当前节点包含子节点,勾选或不勾选全部子节点
     if (e.Node.Nodes.Count > 0)
    {
      SetCheck(e.Node.Nodes, e.Node.Checked);
      return;
    }
    
    //当前节点已勾选，父级节点也要勾选
     if (e.Node.Checked && e.Node.Parent != null && e.Node.Parent.Checked == false)
    {
      SetCheck(e.Node.Parent, true);
      return;
    }
    
    //若当前节点所有同级节点没有勾选，父级节点要取消勾选
     if (e.Node.Parent != null && e.Node.Parent.Checked)
    {
      if (IsNoCheckedAll(e.Node.Parent.Nodes))
      SetCheck(e.Node.Parent, false);
      return;
    }
  }
  
  private static void SetCheck(TreeNodeCollection nodes, bool value)
  {
    if (nodes.Count == 0) return;
    
    TreeView tv = nodes[0].TreeView;
    
    try
    {
      tv.AfterCheck -= OnTreeView_AfterCheck;
      foreach (TreeNode node in nodes) node.Checked = value;
    }
    finally
    {
      tv.AfterCheck += OnTreeView_AfterCheck;
    }
  }
  
  private static void SetCheck(TreeNode node, bool value)
  {
    try
    {
      node.TreeView.AfterCheck -= OnTreeView_AfterCheck;
      node.Checked = value;
    }
    finally
    {
      node.TreeView.AfterCheck += OnTreeView_AfterCheck;
    }
  }
  
  /// <summary>
  /// 是否全部勾选
  /// </summary>
  /// <param name="nodes"></param>
  /// <returns></returns>
   public static bool IsCheckedAll(TreeNodeCollection nodes)
  {
    int count = 0;
    foreach (TreeNode N in nodes) if (N.Checked) count++;
    return count == nodes.Count;
  }
  
  /// <summary>
  /// 是否全部没有勾选
  /// </summary>
  /// <param name="nodes"></param>
  /// <returns></returns>
   public static bool IsNoCheckedAll(TreeNodeCollection nodes)
  {
    int count = 0;
    foreach (TreeNode N in nodes) if (N.Checked == false) count++;
    return count == nodes.Count;
  }
  
}

//来源:C/S框架网 | www.csframework.com | QQ:23404761

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