.net 子串与indexOf函数
可能重复:.net 子串与indexOf函数,.net,vb.net,debugging,.net,Vb.net,Debugging,可能重复: 我有一个问题,我正在绕圈子。错误消息是“无法使用这些参数调用可访问的IndexOf。” 我的教授说“搜索字符串Los Angeles和子字符串将从文本框返回它,但它需要知道开始返回单词的位置,这就是IndexOf的位置。”这是否意味着子字符串和IndexOf一起使用?这就是我所做的,可能是问题所在。代码如下: Private Sub btnOrder_Click(ByVal sender As Object, ByVal e As EventArgs) Handles
我有一个问题,我正在绕圈子。错误消息是“无法使用这些参数调用可访问的IndexOf。” 我的教授说“搜索字符串Los Angeles和子字符串将从文本框返回它,但它需要知道开始返回单词的位置,这就是IndexOf的位置。”这是否意味着子字符串和IndexOf一起使用?这就是我所做的,可能是问题所在。代码如下:
Private Sub btnOrder_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnOrder.Click
'Declare variables
Dim Price As Decimal
Dim txtAddress As String = "Los Angeles"
Dim DialogResults As String
'Begin If Statements to determine whether value is a number
If IsNumeric(txtPrice.Text) Then
MessageBox.Show("Please enter a nummeric value.", "Error Message")
End If
If IsNumeric(txtQuantity.Text) Then
MessageBox.Show("Please enter a numeric value.", "Error Message")
End If
Try
'Condition for Pickup days
If radPickUp.Checked = True Then
Price = CDec(txtPrice.Text)
ElseIf radNextDay.Checked = True Then
Price = CDec(CDbl(txtPrice.Text) * 0.01)
ElseIf radDays.Checked = True Then
Price = CDec(CDbl(txtPrice.Text) * 0.05)
End If
'Condition for Weekdays or Weekends pickup
If CDbl(Str(cboDays.Text)) = -1 Then
Price = CDec(CDbl(txtPrice.Text) * 0.0925)
End If
If CBool(Int(txtAddress.Substring(0, 10))) Then
Str(txtAddress.IndexOf(11, 0))
DialogResults = CStr(MessageBox.Show("Your order is $ " & CDbl(txtPrice.Text) - 0.05))
Else : DialogResults = CStr(MessageBox.Show("You order is $ " & CDbl(txtPrice.Text)))
End If
Catch ex As InvalidCastException
MessageBox.Show("Please enter a valid numeric value to continue.")
End Try
End Sub
Private Sub btnReset_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnReset.Click
'Reset controls
txtPrice.Clear()
txtQuantity.Clear()
txtName.Clear()
txtAddress.Clear()
cboDays.Text = String.Empty
txtPrice.Focus()
End Sub
Private Sub btnExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExit.Click
'Quit the application
Me.Close()
End Sub
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
MessageBox.Show("Hello", "A greeting.")
End Sub
有什么建议吗?是你的朋友
你打电话
Str(txtAddress.IndexOf(11, 0))
这是无效的语法。正确的语法是
string.IndexOf(searchString)
这将返回找到的字符串的索引位置
-1如果找不到它
0如果为空请使用MSDN的最新版本,直到明确说明其他版本,例如。