以编程方式将控件添加到表单

Question

我正在使用附加的代码在现有集合下添加另一行\控件行(单击标签时).可能会添加相当多的行,因此我不得不使用计数器(i)多次重复代码以跟踪...

这样做有更好的方法吗？

Private Sub Label10_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)      Handles LblExpandSearch.Click
    If i = 0 Then

        'TextBox7
        '
        Dim TextBox7 As New TextBox
        TextBox7.Size = New Size(302, 20)
        TextBox7.Name = "TextBox7"
        TextBox7.Location = New System.Drawing.Point(60, 135)
        Me.ExpAdvancedSearch.Controls.Add(TextBox7)

        'RadioButton5
        '
        Dim RadioButton5 As New RadioButton
        RadioButton5.AutoSize = True
        RadioButton5.Checked = True
        RadioButton5.Location = New System.Drawing.Point(77, 112)
        RadioButton5.Name = "RadioButton5"
        RadioButton5.Size = New System.Drawing.Size(55, 17)
        RadioButton5.TabIndex = 48
        RadioButton5.TabStop = True
        RadioButton5.Text = "NEAR"
        RadioButton5.UseVisualStyleBackColor = True

    ElseIf i = 1 Then

        ExpAdvancedSearch.Size_ExpandedHeight = 260

        'TextBox8
        '
        Dim TextBox8 As New TextBox
        TextBox8.Size = New Size(302, 20)
        TextBox8.Name = "TextBox8"
        TextBox8.Location = New System.Drawing.Point(60, 185)
        Me.ExpAdvancedSearch.Controls.Add(TextBox8)


        'RadioButton9
        '
        Dim RadioButton9 As New RadioButton
        RadioButton9.AutoSize = True
        RadioButton9.Checked = True
        RadioButton9.Location = New System.Drawing.Point(77, 162)
        RadioButton9.Name = "RadioButton9"
        RadioButton9.Size = New System.Drawing.Size(55, 17)
        RadioButton9.TabIndex = 48
        RadioButton9.TabStop = True
        RadioButton9.Text = "NEAR"
        RadioButton9.UseVisualStyleBackColor = True

    End If

    i = i + 1
End Sub

Answer 1

嗯.. UseVisualStyleBackColor对我说'winforms'.

几点......

不要将控件全部添加到一个面板,请使用usercontrol.

然后只需添加其实例.

不要处理标签中的点击事件

使用链接标签或按钮.其他任何东西=对用户意味着什么.当然,你想到了它对你有意义!现在对用户来说,这是黑白分明.

样品...

当然很少.你想要:

• 将项目放在可滚动面板中而不是在表单上.
• 也可能将它们添加到uc的通用列表中.
• 设置表格的最小/最大尺寸 - 允许合理的尺寸(允许任何高度> ~100)
• 设置uc和控制.Anchor属性以允许合理的大小调整

uc.vb

Public Class uc
    Inherits System.Windows.Forms.UserControl

    Private components As System.ComponentModel.IContainer
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents LinkLabel1 As System.Windows.Forms.LinkLabel

    Public Sub New()
        MyBase.New()

        Me.TextBox1 = New System.Windows.Forms.TextBox
        Me.LinkLabel1 = New System.Windows.Forms.LinkLabel
        Me.SuspendLayout()

        Me.TextBox1.Location = New System.Drawing.Point(8, 8)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(88, 20)
        Me.TextBox1.TabIndex = 0
        Me.TextBox1.Text = "TextBox1"

        Me.LinkLabel1.Enabled = False
        Me.LinkLabel1.Location = New System.Drawing.Point(112, 8)
        Me.LinkLabel1.Name = "LinkLabel1"
        Me.LinkLabel1.Size = New System.Drawing.Size(24, 16)
        Me.LinkLabel1.TabIndex = 1
        Me.LinkLabel1.TabStop = True
        Me.LinkLabel1.Text = "add"

        Me.Controls.Add(Me.LinkLabel1)
        Me.Controls.Add(Me.TextBox1)
        Me.Name = "uc"
        Me.Size = New System.Drawing.Size(148, 36)
        Me.ResumeLayout(False)

    End Sub

    Private _addcallback As EventHandler = Nothing
    Public Property AddCallback() As EventHandler
        Get
            Return _addcallback
        End Get
        Set(ByVal Value As EventHandler)

            _addcallback = Value
            LinkLabel1.Enabled = Not Value Is Nothing

        End Set
    End Property

    Private Sub LinkLabel1_LinkClicked(ByVal sender As System.Object, ByVal e As System.Windows.Forms.LinkLabelLinkClickedEventArgs) Handles LinkLabel1.LinkClicked
        If AddCallback Is Nothing Then Throw New ApplicationException("AddCallback not set on a uc") ' ALWAYS check for errors like this 
        _addcallback(Me, Nothing)
        AddCallback = Nothing ' gray myself out, can't insert in thie implementation
    End Sub
End Class

frm.vb

Public Class frm
    Inherits System.Windows.Forms.Form

    Private components As System.ComponentModel.IContainer
    Public Sub New()
        MyBase.New()
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(292, 266)
        Me.Name = "Form1"
        Me.Text = "Form1"
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        AddClicked(Me, Nothing)
    End Sub

    Private Sub AddClicked(ByVal sender As Object, ByVal e As System.EventArgs)
        Dim myuc As New uc
        myuc.AddCallback = AddressOf AddClicked
        If Controls.Count > 0 Then
            myuc.Top = Controls(Controls.Count - 1).Bottom
        End If
        Me.Controls.Add(myuc)
    End Sub
End Class