对窗体控件的循环

[zbfeyan]

请问怎样对窗体的文本框、组合框进行循环，识别哪个文本框或组合框没有输入值？
怎么控制用于输入数字的文本框中的数字位数？

[tjficcbw]

怎么控制用于输入数字的文本框中的数字位数？

   Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
        If (TextBox1.Text).Length > 4 Then TextBox1.Text = (TextBox1.Text).Substring(0, 4)
    End Sub

对窗体的文本框、组合框进行循环

       For   Each   objCTRLS   In   Me.Controls   
                  If   TypeName(objCTRLS)   =   "textbox"  or  TypeName(objCTRLS)   =   "combobox"   Then   
 '........
                  End   If   
       Next   objCTRLS   

[wuyq11]

For Each c As Windows.Forms.Control In Me.Controls
If TypeOf c Is Windows.Forms.ComboBox Then
Dim com As System.Windows.Forms.ComboBox = DirectCast(control, System.Windows.Forms.ComboBox )
ElseIf TypeOf c Is Windows.Forms.TextBox Then
Dim tb As System.Windows.Forms.TextBox = DirectCast(control, System.Windows.Forms.TextBox)
End If
Next

[hitlcyu19]

foreach (System.Windows.Forms.Control control in this.Controls)
{
if (control is System.Windows.Forms.TextBox)
{
System.Windows.Forms.TextBox tb = (System.Windows.Forms.TextBox)control ;
//有没有输入值 Text属性
//MaxLength
}
}