VB控件数组之操作技巧

一.运行中设置数组控件的属性

设窗体上有若干个以 Command1 命名的命令按钮，现要求：点击其中一个按钮后，该按钮不可用，而其它的按钮均可用。以下几行代码可以实现这个要求，比一个一个的设置高效得多。

Private Sub Command1_Click(Index As Integer)Dim i As Integer '计数器Dim comNum As Integer '按钮的索引号comNum = 0For i = 0 To Command1.Count - 1comNum = comNum + 1If comNum > Command1.Count - 1 Then comNum = 0Command1(comNum).Enabled = True '让所有按钮可用NextCommand1(Index).Enabled = False '让被单击按钮不可用End Sub

二、运行中添加和卸载数组控件

窗体上已有一个文本框Text1，程序需要在运行时动态地创建若干文本框，可这样实现：

1.首先，设计时给Text1的Index属性设置为"0"，这一步很重要：有了索引号才能创建数组控件；

2.编写代码：[之前请给工程添加两个命令按钮,Name属性取缺省值，Caption属性分别为：添加、卸载]

Private Sub Command1_Click()Dim txtNum As Integer 'Text1的Index号Dim Num As Integer '赋给各TextBox的值txtNum = 0 '初值Num = 1 '初值Text1(0).Text = "Text" & Num '第一个Text1的值Dim i As Integer '计数器For i = 0 To 4 '添加五个TextBoxtxtNum = txtNum + 1Num = Num + 1Load Text1(txtNum) '加载文本框Text1(txtNum).Top = Text1(txtNum - 1).Top + 450 '设置位置Text1(txtNum).Text = "Text" & Num '加载内容Text1(txtNum).Visible = True '令其可见:不能漏NextCommand1.Enabled = False Command2.Enabled = TrueEnd SubPrivate Sub Command2_Click()Dim i As Integer, N As IntegerN = 0For i = 1 To Text1.Count - 1N = N + 1Unload Text1(N)NextCommand1.Enabled = TrueCommand2.Enabled = FalseEnd Sub

三、给运行中添加的数组控件命名并编写事件

其实例二已经给数组控件命了名，只是简单了些。本例将文件夹"F:\Txt"下的所有.txt的文件名作为菜单的Caption添加到菜单项里[请事先建立此文件夹并拷贝一些.txt文件，或者更改代码],当点击这些菜单，程序将调出Windows的记事本打开相应的文件。
键入以下代码前请启动VB的菜单编辑器，建立一个父菜单项[Naem和Caption属性任意]，然后在此父菜单下建立一个子菜单，Name属性为"mnuFiles",Caption属性为"没有文件"。

Dim MyPath As String '路径名变量'添加并命名菜单过程Private Sub AddMenu()Dim MenuNum As Integer '菜单索引号变量Dim MyFiles As String '文件名变量MenuNum = 0 '初值MyFiles = Dir(MyPath + "*.txt") '仅查找文本文档If MyFiles = "" Then Exit Sub '为空则退出过程mnuFiles(0).Caption = MyFiles '给第一个菜单命名Do Until MyFiles = ""MyFiles = Dir()If MenuNum = 0 Then MenuNum = 1MenuNum = MenuNum + 1Load mnuFiles(MenuNum) '加载菜单mnuFiles(MenuNum).Visible = True '设置为可见：不能漏mnuFiles(MenuNum).Caption = MyFilesIf mnuFiles(MenuNum).Caption = "" Then Unload mnuFiles(MenuNum)'若菜单名为空则卸载掉LoopEnd SubPrivate Sub Form_Load()MyPath = "F:\Txt\" '规定路径Call AddMenu '执行添加菜单过程End SubPrivate Sub mnuFiles_Click(Index As Integer)Dim ret As String'用Windows的记事本打开文件:注意中间的空格不能少ret = "Notepad.exe" & " " & MyPath & mnuFiles(Index).CaptionShell ret, vbNormalFocusEnd Sub

四、控件在窗体上的排列问题
当然添加的数组控件多了，排列确实是个问题。下面的例子给窗体添加499个Label控件，加上事先绘制好的Index号定义为0的控件，总共有500个，能在窗体上从左到右、从上到下整齐地排列。程序运行时要花些许时间。

Option ExplicitPrivate Sub Form_Load()Me.Width = 6800Me.Height = 6000Me.Caption = "添加标签演示"With Label1(0).Top = 0.Left = 120.Height = 200.Width = 300.Caption = ""End WithAddLabelsEnd SubPrivate Sub AddLabels()Dim i As Integer '计数器Dim Num As Integer 'Label的Index号Dim k As Integer '判断是否满行Dim n As Integer '行数计数器Num = 0k = 0n = 0Label1(0).Caption = Num + 1For i = 1 To 499Num = Num + 1Load Label1(Num) '加载Label控件Select Case k Case 0Label1(Num).Left = Label1(Num - 1).Left + Label1(0).Width + 20If Num = 20 Then n = n + 1: k = nCase nLabel1(n * 20).Left = 120Label1(n * 20).Top = Label1(0).Height * nLabel1(Num).Top = Label1(0).Height * nLabel1(Num).Left = Label1(Num - 1).Left + Label1(0).Width + 20If Num = (n + 1) * 20 Then n = n + 1: k = nEnd Select Label1(Num).Caption = Num + 1Label1(Num).Visible = TrueNextEnd Sub