在vb.net中执行阅读器问题 [英] Execute Reader Problem in vb.net

问题描述

我是vb.net的新手，正在从事一个项目，该项目显示了从ms sql db到listview的数据.但是，我遇到了问题，陷入了如下问题:

Hi,

I am new to vb.net and i am working on a project which shows data from the ms sql db to the listview. However, i am having a problem and got stucked as below:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

       lvwTest.View = View.Details
       lvwTest.Columns.Add("Customer Name", 100, HorizontalAlignment.Left)


       Dim command As SqlCommand = _
           New SqlCommand("SELECT CustName FROM Report", Connection)

       Connection.Open()
       Dim reader As SqlDataReader = command.ExecuteReader()
       Do While (reader.Read())
           lvwTest.Items.Add(reader.GetInt32(0))       
Loop
       reader.Close()
       Connection.Close()
   End Sub

有人可以帮我解决这个问题.

非常感谢.

Can someone help me out with this problem.

Thank you very much.

推荐答案

直接来自文档的示例；

Example straight from the docs;

Dim reader As SqlClient.SqlDataReader
Dim recordData As String = ""
Dim recordCount As Integer = 0
Dim i As Integer = 0
sqlConnection1.Open()
reader = sqlDataAdapter1.SelectCommand.ExecuteReader()
While reader.Read()
    For i = 0 To reader.FieldCount - 1
        recordData &= reader(i).ToString()
        recordData &= "-"
    Next
    recordData &= ControlChars.CrLf
    recordCount += 1
End While
sqlConnection1.Close()
MessageBox.Show("Records processed: " & recordCount)
MessageBox.Show("Data:" & ControlChars.CrLf & recordData)

但是，我将使用一个绑定源，然后将控件绑定到该源.

在MSDN上有一个很好的视频，关于基于数据的表单"，并且该系列中还有其他一些值得一看.
http://msdn.microsoft.com/en-gb/vbasic/bb725824.aspx [ ^ ]

However, i would use a bindingsource, and then bind the controls to that.

There is a good video on MSDN on Forms over Data, and there are a few others in the series that are worth watching.
http://msdn.microsoft.com/en-gb/vbasic/bb725824.aspx[^]

您没有确切说明问题所在，因此很难说.

但是，我确实注意到您正在尝试读取一个整数值，并且列表视图列的名称(客户名称")表明CustName字段是varchar/string.

在这种情况下，您应该使用reader.GetString(0)而不是reader.GetInt32(0)

祝你好运，
约翰尼·J.

You don''t specify exactly what the problem is, so it''s hard to say.

I do however notice that you''re trying to read an integer value, and the name of your listview column ("Customer Name") suggests that the CustName field is a varchar/string.

In that case you should use reader.GetString(0) instead of reader.GetInt32(0)

Good luck,
Johnny J.

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