在VB.NET中访问添加(子)控件

Question

用这段代码，我动态添加了一个面板，里面有两个面板(一个标题和一个数据面板(。在"数据"面板中，还有一个我喜欢访问的标签。

现在我喜欢访问数据面板内的标签，但无法使用访问它

test_label.text = "this a second test"

这里的动态添加面板

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim newPanelMain As Panel = New Panel With {
.Location = New Point(200, 500),
.Name = "test",
.Size = New Size(500, 500)
}
Dim newPanelHeader As Panel = New Panel With {
.Name = newPanelMain.Name & "_header",
.BackColor = Color.Orange,
.Dock = DockStyle.Top,
.Height = 50
}
newPanelMain.Controls.Add(newPanelHeader)
Dim newPanelData As Panel = New Panel With {
.Name = newPanelMain.Name & "_data",
.Dock = DockStyle.Fill,
.BorderStyle = BorderStyle.FixedSingle
}
newPanelMain.Controls.Add(newPanelData)
Dim newPanelSize As Panel = New Panel With {
.Name = newPanelMain.Name & (("_size")),
.BackColor = Color.Red,
.Height = 20,
.Width = 20,
.Location = New Point(newPanelData.Width - 20, newPanelData.Height - 20)
}
newPanelData.Controls.Add(newPanelSize)
Dim newLabel As Label = New Label With {
.Text = "This is a test",
.Name = newPanelMain.Name & (("_label")),
.Location = New Point(0, 0),
.AutoSize = True
}
newPanelData.Controls.Add(newLabel)

Me.Controls.Add(newPanelMain)

End Sub

Answer 1

将newLabel声明为成员变量：

Private newLabel As Label

所以你可以使用这个代码：

Me.newLabel = New Label With {
.Text = "This is a test",
.Name = newPanelMain.Name & (("_label")),
.Location = New Point(0, newPanelHeader.Height + 10),
.AutoSize = True
}
newPanelData.Controls.Add(Me.newLabel)

然后使用更改其.Text属性

Me.newLabel.Text = "this a second test"

在不同的情况下(例如，如果您在运行时创建了多个Labels(，请记住您可以使用Control.ControlCollection类：

CType(CType(Me.Controls("test"), Panel).Controls("test_data"), Panel).Controls("test_label").Text = "this is a third test"