Question

让代码吼叫;逻辑中出现错误，不显示错误消息。我正在尝试使用treeview1更改事件来过滤textbox1.text控件。

预期结果是在treeview1中保留仅与textbox1.text类似的节点（SQL中的％text％）

我在C#找到了很多解决方案的结果，但无法在 VB.NET 中找到答案。

Referencing this answer，并将代码转换为VB.NET，几乎没有变化仍然无效：

Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
        Try
            Dim FilterText As String = TextBox1.Text
            TreeView1.BeginUpdate()
            If (FilterText IsNot String.Empty) Then
                For Each Node As TreeNode In TreeView1.Nodes
                    If Not Node.Text.Contains(FilterText) Then
                        Node.Remove()
                        TreeView1.Refresh()
                    End If
                Next
            Else
                Exit Sub
            End If
            TreeView1.EndUpdate()
        Catch ex As Exception
        End Try
    End Sub

Answer 1

以下是代码我只为所选节点着色。你可以根据需要改变

Public Class Form1

Dim matchedNodes As List(Of TreeNode) = New List(Of TreeNode)
Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged

    matchedNodes.Clear()
    If Not String.IsNullOrEmpty(TextBox1.Text) Then
        TreeView1.BeginUpdate()
        For Each node As TreeNode In TreeView1.Nodes
            FindRecursive(node)
        Next
        TreeView1.EndUpdate()

    End If
    For Each match In matchedNodes
        match.BackColor = Color.Yellow
    Next
    TreeView1.Refresh()
End Sub
Private Sub FindRecursive(treeNode As TreeNode)
    treeNode.BackColor = Color.White
    If treeNode.Text.Contains(TextBox1.Text) Then
        matchedNodes.Add(treeNode)
    End If

    For Each node As TreeNode In treeNode.Nodes
        If node.Text.Contains(TextBox1.Text) Then
            matchedNodes.Add(node)
        End If
        FindRecursive(node)
    Next
End Sub
End Class

Answer 2

经过几个帖子的阅读;将过滤器应用于treeview非常简单。即使我最初想要隐藏其他不在过滤器中的节点，但这段代码是实用的并且可以完成工作。

 Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
        Dim TxtToFilter As String = TextBox1.Text
        Dim NodeItem As TreeNode
        For Each NodeItem In TreeView1.Nodes
            If NodeItem.Text.ToLower.Contains(TxtToFilter.ToLower)  And TxtToFilter IsNot String.Empty Then
                NodeItem.EnsureVisible()
                NodeItem.BackColor = Color.Yellow
            Else
                NodeItem.BackColor = TreeView1.BackColor
            End If
        Next
    End Sub

注意：当所有节点都是我的app逻辑中的root / parents时，此代码有效。没有测试子节点。

使用VB.NET winforms中的文本框过滤树视图

2 个答案: