如何创建可在任意Private Sub中使用的VB控件数组？

错误原因 #

你在类级别直接初始化buttonArray时，Form的控件还没完成实例化（控件是在Form构造过程中创建的），所以数组里的Button1到Button16都是Nothing，点击按钮调用btnStart_Click时访问这些空对象就会触发Object reference not set to an instance of an object错误。

解决方案 #

有几种方法可以让控件数组在类级别可用且正常工作：

方法1：在Form的Load事件中初始化数组

把数组声明留在类级别，但延迟到Form加载完成后再赋值：

Public Class Form1
    Dim buttonArray As Button() ' 只声明不初始化

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ' Form加载完成后，控件已实例化，此时赋值数组
        buttonArray = {Button1, Button2, Button3, Button4, Button5, Button6,
                       Button7, Button8, Button9, Button10, Button11, Button12,
                       Button13, Button14, Button15, Button16}
    End Sub

    Private Sub btnStart_Click(sender As Object, e As EventArgs) Handles btnStart.Click
        For Each btn In buttonArray
            btn.Text = "test"
        Next
    End Sub
End Class

方法2：使用ReadOnly结合延迟初始化（VB 14+支持）

利用ReadOnly字段和Lambda表达式延迟初始化，确保控件实例化后才创建数组：

Public Class Form1
    ReadOnly buttonArray As Button() = Function() {Button1, Button2, Button3, Button4, Button5, Button6,
                                                   Button7, Button8, Button9, Button10, Button11, Button12,
                                                   Button13, Button14, Button15, Button16}.Invoke()

    Private Sub btnStart_Click(sender As Object, e As EventArgs) Handles btnStart.Click
        For i = 0 To buttonArray.Length - 1
            buttonArray(i).Text = "test"
        Next
    End Sub
End Class

方法3：动态查找控件（更灵活，适合控件数量多的场景）

如果不想手动列举所有按钮，可以通过Controls.Find方法按名称匹配控件，自动填充数组：

Public Class Form1
    Dim buttonArray As Button()

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        ' 查找所有名称以"Button"开头的控件，转换为Button数组
        buttonArray = Me.Controls.Find("Button*", True).OfType(Of Button)().ToArray()
    End Sub

    Private Sub btnStart_Click(sender As Object, e As EventArgs) Handles btnStart.Click
        For Each btn In buttonArray
            btn.Text = "test"
        Next
    End Sub
End Class

注意事项 #

• 确保所有按钮控件的名称确实是Button1到Button16，没有拼写错误
• 如果按钮放在容器控件（比如Panel、GroupBox）里，方法3需要把Me.Controls换成容器控件的Controls，或者保持Find方法的第二个参数为True（递归查找子控件）

内容的提问来源于stack exchange，提问作者user19169409