Question

我想用mysql数据库中的数据填充一个数组

这是我的代码

Dim DataBlob As String()
        Dim Count As Integer

        While READER.Read
            Count += 1
            Dim eName As String = READER(1)
            Dim eSname As String = READER(2)
            Dim eID As String = READER(0)

            DataBlob(Count) = eSname + eName

        End While

        Return DataBlob

但我没有看到任何回复。可能是什么问题

注意：有一条警告说明：DataBlob is used before a value is assigned

Answer 1

如果你想使用数组，只需获得第一个计数

Dim Count as integer=reader_count(0)  
Dim DataBlob(count-1) As String
'subtract 1 b/c array starts at zero
Dim i as integer=0
While READER.Read
        Dim eName As String = READER(1)
        Dim eSname As String = READER(2)
        Dim eID As String = READER(0)
        DataBlob(i) = eSname + eName
        i+=1
End While

另一个选择，如果你知道你的数量是有限的（让我们说你的读者总是拉动世界各国，你可能只是高估），然后当你完成后，你重新调整数组，但你必须使用保存。除非你正在处理小数组，否则我不会这样做。

'there is no way the reader will return more than 500
Dim DataBlob(500) As String
While READER.Read
        Count += 1
        Dim eName As String = READER(1)
        Dim eSname As String = READER(2)
        Dim eID As String = READER(0)
        DataBlob(Count) = eSname + eName
End While
ReDim Preserve DataBlob(Count)

VB.Net不使用db数据填充数组

1 个答案: