关于清空件内容的问题. Private Sub s_ClearControl() On Error GoTo Err_Msg Dim ctl As control Dim nCount As Integer For Each ctl In Me.Controls If TypeOf ctl Is TextBox Then ctl.Text = " " ElseIf TypeOf ctl Is DTPicker Then ctl.value = Date ElseIf TypeOf ctl Is ComboBox Then ctl.ListIndex = -1 End If Next Exit Sub Err_Msg: MsgBox(Err.Description) End Sub 上面这段代码是VB中用于我清空TextBox,ComboBox 三种控件的内容及对DTPicker控件进行初使化.现在要升成VB.net 后 trl.value=date 和ctl.ListIndex = -1 提示不是System.Windows.Forms.Control控件 下面是升成后的代码.有一点点改动了. Private Sub s_ClearControl() On Error GoTo Err_Msg Dim ctl As System.Windows.Forms.Control Dim nCount As Short For Each ctl In Me.Controls If ctl.Name = "TextBox " Then ctl.Text = " " ElseIf ctl.Name = "DateTimePicker " Then ctl.value = Today ElseIf ctl.Name = "ComboBox " Then ctl.ListIndex = -1 End If Next ctl Exit Sub Err_Msg: MsgBox(Err.Description) End Sub 各位大大有什么好的办法帮忙解决一下的.... __________________________________________________________________________ Imports System.Data Imports System.Data.OleDb Public Class Form1 Private Sub Form1_Load(ByVal sender As Object,ByVal e As System.EventArgs) Handles Me.Load Me.DateTimePicker1.Value = "#1990-9-10# " Me.DateTimePicker2.Value = "#1991-9-10# " Me.ComboBox1.Items.Add( "11111 ") Me.ComboBox1.Items.Add( "22222 ") Me.ComboBox1.SelectedIndex = 0 Me.ComboBox2.Items.Add( "33333 ") Me.ComboBox2.Items.Add( "44444 ") Me.ComboBox2.SelectedIndex = 0 Me.TextBox1.Text = "text " Me.TextBox2.Text = "alse text " End Sub Private Sub Button1_Click(ByVal sender As Object,ByVal e As System.EventArgs) Handles Button1.Click Try Dim ctl As System.Windows.Forms.Control For Each ctl In Me.Controls If TypeOf (ctl) Is TextBox Then ctl.Text = " " ElseIf TypeOf ctl Is DateTimePicker Then Dim d As DateTimePicker = ctl d.Value = Today ElseIf TypeOf ctl Is ComboBox Then Dim cb As ComboBox = ctl cb.SelectedIndex = -1 End If Next ctl Catch ex As Exception MsgBox(ex.Message) End Try End Sub End Class __________________________________________________________________________ 重新定义一个变量用于赋值吗?,我去试试 __________________________________________________________________________ 其实用CType应该可以的，但是我不太会用。 __________________________________________________________________________ 用Ctype： Public Class Form1 Private Sub Form1_Load(ByVal sender As Object,ByVal e As System.EventArgs) Handles Button1.Click Try Dim ctl As System.Windows.Forms.Control For Each ctl In Me.Controls If TypeOf (ctl) Is TextBox Then ctl.Text = " " ElseIf TypeOf ctl Is DateTimePicker Then CType(ctl,DateTimePicker).Value = Today ElseIf TypeOf ctl Is ComboBox Then CType(ctl,ComboBox).SelectedIndex = -1 End If Next ctl Catch ex As Exception MsgBox(ex.Message) End Try End Sub End Class __________________________________________________________________________ 两位的都试过可以的.谢谢. __________________________________________________________________________ 晕死，明明是我一个人啊……不是不啊……难道…… __________________________________________________________________________