索引和长度必须引用字符串中的位置。“＆vbCrLf＆”参数名称：length vb.net

Question

Public Sub Main(temp As String)
    Dim AccNo As String = temp.Substring(0, 18)
    Dim Identifier As String = temp.Substring(36, 46)
    Dim Expected As String = temp.Substring(45, 98)
    Dim Received As String = temp.Substring(100, 105)
    Dim Length As String = temp.Length.ToString
    lbLength.Text = Length.ToString

    lbAcc.Text = AccNo.ToString
    lbIdentifier.Text = Identifier.ToString
    lbExpected.Text = Expected.ToString
    lbReceived.Text = Received.ToString
End Sub

我正在尝试从字符串行中提取一个部分。它先正常工作两次，然后生成

  

索引和长度必须引用字符串中的位置。”＆vbCrLf＆“参数名称：length vb.net”

请帮助我解决这个问题。

Answer 1

Substring（StartPosition，length）长度是从起始位置开始的字符数。

如果您想像Substring（start_position，end_position）那样将结束位置替换为（98-45），因为end-start = length

Answer 2

在Sub的开头检查临时字符串的长度。

Dim temp As String = ""
    If temp.Length < 205 Then
        MessageBox.Show("String is too short to process")
        Exit Sub
End If