将读取器项存储在数组中

Question

Dim myReader As OleDbDataReader
Dim Index As Integer
Dim status As Array
Index = 0
cmd.CommandText = "SELECT CPALLOCATIONTIME from RECORDMASTER where ID='" & TxtID.Text & "'"
cmd.CommandType = CommandType.Text
myReader = cmd.ExecuteReader()

Do While myReader.Read()
     status(Index) = myReader.Item(0)
     Index = Index + 1
Loop

myReader.Close()

If (Index = 2) Then
If ((status(0) = "Fp" Or status(0) = "Op") And status(1) = "OXp") Then
    qText = TxtSTS.Text + "X"
    Update = True
    ApplicationStatus = 2
ElseIf ((status(0) = "Fp" Or status(0) = "Op") And status(1) = "FXp") Then
    qText = TxtSTS.Text + "X"
    Update = True
    ApplicationStatus = 2
End If

有人可以帮助我status(Index) = myReader.Item(0)，给出转化错误

Answer 1

1. 您希望在添加元素时，您的阵列成长。这不是阵列的用途。请改用List(Of T)。 （有关确切语法，请参阅examples on MSDN。）

2. 确保从阅读器读取的数据具有正确的数据类型。你有两种方法：

   1. 投了它（例如DirectCast(myReader(0), String)）或
   2. （更好）使用已经返回正确数据类型的reader方法，例如myReader.GetString(0)。

Answer 2

尝试

status(Index) = myReader.Item(0).ToString

Answer 3

Redim status(0) ' < -- declare like this

然后在循环

Redim preserve status(index)
status(Index) = myReader("Column_name")
index = index + 1