Vb.net 需要帮助比较字符串和带有循环的列表框吗

代码如下。我试图将一个用户输入字符串与一个大的列表框进行比较，如果它找到匹配项，它将终止循环并打印响应。我总是挂断它冻结或打印错误的响应

Private Sub btnAction_Click(sender As Object, e As EventArgs) Handles btnAction.Click
        Dim input As String = txtIn.Text
        Dim i As Integer = 0
        While i <= lstRoseBowl.Items.Count - 1
            If input = CStr(lstBox.Items(i)) Then
                txtOut.Text = "Yes"
            Else
                txtOut.Text = "No"
            End If
        End While
    End Sub

Private Sub-btnAction\u单击（发送者作为对象，e作为事件参数）处理btnAction。单击
尺寸输入为字符串=txtIn.Text
尺寸i为整数=0
当i时，您需要增加“i”

现在，它将编译并运行，但可能不会给出您想要的结果，因为如果它在第一次尝试时找到项目，那么在第二次尝试时将显示No。有更好的方法可以做到这一点，但对于最少的代码更改，它可能看起来像这样

Private Sub btnAction_Click(sender As Object, e As EventArgs) Handles btnAction.Click
        Dim input As String = txtIn.Text

        txtOut.Text = "No"

        For i As Integer = 0 To lstRoseBowl.Items.Count - 1
            If input = CStr(lstBox.Items(i)) Then
                txtOut.Text = "Yes"
                Exit For
            End If
        Next
    End Sub

需要循环吗？太好了，谢谢。现在我明白了为什么我的教授总是在循环中做任何事情之前先做增量运算，这非常容易忘记！你应该问你的老师如何使用断点，并逐步通过代码，你会很快找到它。
Private Sub btnAction_Click(sender As Object, e As EventArgs) Handles btnAction.Click
        Dim input As String = txtIn.Text

        For i As Integer = 0 To lstRoseBowl.Items.Count - 1
            If input = CStr(lstBox.Items(i)) Then
                txtOut.Text = "Yes"
            Else
                txtOut.Text = "No"
            End If
        Next
    End Sub

Private Sub btnAction_Click(sender As Object, e As EventArgs) Handles btnAction.Click
        Dim input As String = txtIn.Text

        txtOut.Text = "No"

        For i As Integer = 0 To lstRoseBowl.Items.Count - 1
            If input = CStr(lstBox.Items(i)) Then
                txtOut.Text = "Yes"
                Exit For
            End If
        Next
    End Sub