textbox的值怎么在外部函数调用？

[csuchen6]

Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
        TextBox1.Text = 0
        Dim SmallValue As Single
        SmallValue = TextBox1.Text
    End Sub

我有两个问题，都比较菜鸟，请不吝赐教啊。
其一：我怎样在TextBox内显示默认值？
其二：这里的SmallValue = TextBox1.Text的值怎么能在外部方法里面调用？谢谢了。

[fsh1985]

定义个类外部访问变量，这样实例化个类的变量，就能访问到这个变量

默认只的话，就是在这个窗体的Load 事件写
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
TextBox1.Text = "0"
End Sub

[cosmo_sei]

1 在窗体show出来前的任意阶段给textbox赋值均可，可以在构造函数New里；也可以在designer里设置，design的初始化其实是New里面调用InitializeCompoment方法实现的；也可以在load里，就是1楼给出来的例子。关键要了解form的生命周期。

2 封装为属性，smallvalues应该定义为域。

Dim _smallValue As Single ''定义在外面
Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
        TextBox1.Text = 0        
        _smallValue = TextBox1.Text
End Sub

Property ReadOnly SmallValue As Single
    Get
        Return _smallValue
    End Get
End Property

而实际上，没有必要定义smallvalue，直接用一个属性返回转化后的textbox的值即可，属性定义

Property ReadOnly SmallValue As Single
    Get
        Return CType(TextBox1.Text, Single)
    End Get
End Property

假设类名为 C，外部访问 C.SmallValue 即可

[cosmo_sei]

属性加上public声明

[cosmo_sei]

假设类名为 C -> 假设类的实例名为 C

[csuchen6]

感谢三位兄台，问题解决了！

[wl58796351]

Public Class Form1

    Property RetValue As String
        Get
            Return TextBox1.Text
        End Get
        Set(value As String)
            TextBox1.Text = value
        End Set
    End Property


    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        TextBox1.Text = "moren"
    End Sub

    Private Sub TextBox1_TextChanged(sender As System.Object, e As System.EventArgs) Handles TextBox1.TextChanged
        TextBox1.Text = 0
        Dim SmallValue As Single
        SmallValue = TextBox1.Text
    End Sub
End Class

'*****外部调用*****
Class Waibu
    Dim frm As New Form1
    Dim Mystr As String

    Public Sub ReadTxt()
        Mystr = frm.RetValue
    End Sub
End Class