Public Class Form1
创新互联专注于奇台企业网站建设,成都响应式网站建设,商城开发。奇台网站建设公司,为奇台等地区提供建站服务。全流程定制开发,专业设计,全程项目跟踪,创新互联专业和态度为您提供的服务
Private Imgfile As String
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
ListBox1.DrawMode = DrawMode.OwnerDrawVariable
Imgfile = "X:\Users\......\Pictures\ssm.png"‘显示为listbox的每一行文字前面的图标文件,换一张你自己的图片。
End Sub
Private Sub ListBox1_DrawItem(sender As Object, e As DrawItemEventArgs) Handles ListBox1.DrawItem
e.DrawBackground()
Dim rect As Rectangle = New Rectangle(2, e.Bounds.Y + 2, e.Bounds.Height, e.Bounds.Height - 4)
e.Graphics.DrawImage(New Bitmap(Imgfile), rect)
e.Graphics.DrawString(sender.Items(e.Index), sender.Font, New SolidBrush(sender.ForeColor), _
New RectangleF(e.Bounds.X + rect.Width, e.Bounds.Y, e.Bounds.Width, e.Bounds.Height))
e.DrawFocusRectangle()
End Sub
End Class
预先准备三个图标文件,用于树型控件中显示磁盘符号和文件夹的图像之用。
1、窗体上添加控件如下:
组合框控件 ComboBox1,树型控件 TreeView1,列表框控件 ListBox1,图像列表控件 ImageList1。
选中TreeView1,设置其ImageList属性为ImageList1。
2、设置属性
选中图像列表控件 ImageList1,在属性窗口里,选中属性Images,单击三个小点按钮,出现图像集合编辑器窗口,单击[添加按钮],一一把准备好的图标文件进行添加,注意先后次序,如果不符合要求可以通过上下移动按钮重新改变次序。完成后单击[确定]。
运行图如下:
完整代码如下:
Imports System.IO
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'添加系统所有磁盘目录符号
For Each MyDrive As String In Environment.GetLogicalDrives()
ComboBox1.Items.Add(MyDrive)
Next
'显示第一个磁盘符号
ComboBox1.Text = ComboBox1.Items(0)
End Sub
'递归过程添加目录树
Public Sub AddDirectory(ByVal strFatherPath As String, ByVal strPath As String, ByVal nodeFather As TreeNode)
Dim i As Integer
Dim Mynode As New TreeNode
'先添加本目录
Mynode.Text = Strings.Replace(strPath, strFatherPath "\", "", , 1)
'为节点指定未被选中时显示的图标
Mynode.ImageIndex = 1
'为节点指定被选中时显示的图标
Mynode.SelectedImageIndex = 2
nodeFather.Nodes.Add(Mynode)
Application.DoEvents()
Try
Dim str() As String = Directory.GetDirectories(strPath)
'递归遍历该目录的子文件夹
For i = 0 To str.GetUpperBound(0)
AddDirectory(strPath, str(i), Mynode)
Next
Catch ex As Exception
Debug.WriteLine(ex.Message)
End Try
Mynode = Nothing
End Sub
'根据给出的盘符添加目录树
Private Sub AddRootDirectory(ByVal DiscSymbol As String)
Dim Nynode As New TreeNode
'先把磁盘盘符添加到树中
TreeView1.Nodes.Clear()
Nynode.ImageIndex = 0
Nynode.Text = DiscSymbol
Nynode.SelectedImageIndex = -1
TreeView1.Nodes.Add(Nynode)
Dim i As Integer
'获取磁盘根目录下的文件夹
Dim str() As String = Directory.GetDirectories(DiscSymbol "\")
For i = 0 To str.GetUpperBound(0)
'调用递归过程遍历该文件夹里的所有子文件夹,并添加到树型控件
AddDirectory(DiscSymbol, str(i), Nynode)
Next
Nynode = Nothing
End Sub
Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged
'根据磁盘符号的变更,显示根目录里的文件
ListBox1.Items.Clear()
For Each MyFile As String In System.IO.Directory.GetFiles(ComboBox1.Text)
ListBox1.Items.Add(MyFile)
Next
'根据磁盘符号的变更,重新显示目录树
Dim DiscSymbol As String
DiscSymbol = Microsoft.VisualBasic.Left(ComboBox1.Text, Len(ComboBox1.Text) - 1)
Call AddRootDirectory(DiscSymbol)
End Sub
'递归过程根据子目录寻找上级目录名--从而构成完整的目录路径
Private Sub AllPath(ByVal ThisNode As TreeNode, ByRef MyPathName As String)
If ThisNode.Level 1 Then
'该节点层数大于1,其父节点不是磁盘根目录
MyPathName = ThisNode.Parent.Text "\" MyPathName
Dim MyNode As TreeNode = ThisNode.Parent
Call AllPath(MyNode, MyPathName)
Else
'该节点层数等于1,其父节点就是磁盘根目录
MyPathName = ComboBox1.Text MyPathName
End If
End Sub
Private Sub TreeView1_AfterSelect(ByVal sender As System.Object, ByVal e As System.Windows.Forms.TreeViewEventArgs) Handles TreeView1.AfterSelect
'为了搜索选中的节点对应目录的文件,需要组成全路径
Dim MyAllPathName As String = TreeView1.SelectedNode.Text
Dim MyNode As TreeNode = TreeView1.SelectedNode
If TreeView1.SelectedNode.Level = 0 Then
'如果选中的是根节点
MyAllPathName = ComboBox1.Text
Else
'如果选中的是非根节点,调用递归过程组成全路径
Call AllPath(MyNode, MyAllPathName)
MyAllPathName = MyAllPathName "\"
End If
'根据路径,搜索文件名并显示
ListBox1.Items.Clear()
For Each MyFile As String In System.IO.Directory.GetFiles(MyAllPathName)
ListBox1.Items.Add(MyFile)
Next
End Sub
End Class
先拖一个DataGridView到界面,然后代码里
Me.DataGridView1.DataSource = dt
接收数据时,使用一个 Label 显示就行了。而且跳过一些数据再显示,例如一秒钟才显示一个数据。
你应该把精力放到领导(或者用户)的意图上,不要纠结技术上的 ListBox。