ComboBox添加项目 [英] ComboBox add item

问题描述

嗨！

我正在尝试在运行时从数据库中向组合框添加项目，因为我正在编写以下代码:

Dim cn As OleDbConnection
昏暗的cmd作为System.Data.OleDb.OleDbCommand
Dim da As OleDbDataAdapter
Dim dr As Data.OleDb.OleDbDataReader
Dim str As String
昏暗的icount为整数
Dim ds As DataSet


在form_laod事件中


cn =新的OleDbConnection("Provider = Microsoft.Jet.OLEDB.4.0; Data Source = C:\ Users \ panchani \ Documents \ Visual Studio 2005 \ Transport.mdb")
cmbName.Items.Clear()
cmd.Connection = cn
cmd.CommandText =从item_master中选择nature_of_good"
cn.Open()
dr = cmd.ExecuteReader()
cmbName.Items.Clear()
While(博士阅读)
cmbName.Items.Add(dr(名称"))
结束时

dr.Close()



但是当我运行此表单时，它将在行
上显示错误
dr = cmd.Excutereader()

错误:没有为一个或多个参数给出值

请帮助我！..................谢谢您

解决方案

在您的SQL查询中

cmd.CommandText = "select nature_of_good from item_master"

参数name不存在

cmbName.Items.Add(dr("name"))

Hie!

I am trying to add item in combobox at runtime from database for that i am writing the following code :

Dim cn As OleDbConnection
Dim cmd As System.Data.OleDb.OleDbCommand
Dim da As OleDbDataAdapter
Dim dr As Data.OleDb.OleDbDataReader
Dim str As String
Dim icount As Integer
Dim ds As DataSet


in form_laod event


cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Users\panchani\Documents\Visual Studio 2005\Transport.mdb")
cmbName.Items.Clear()
cmd.Connection = cn
cmd.CommandText = "select nature_of_good from item_master"
cn.Open()
dr = cmd.ExecuteReader()
cmbName.Items.Clear()
While (dr.Read)
cmbName.Items.Add(dr("name"))
End While

dr.Close()



but when i run this form it will dispaly error on line

dr=cmd.Excutereader()

Error : NO Value is given for one or more parameters

Please Help Me !..................Thank you

解决方案

in your sql query

cmd.CommandText = "select nature_of_good from item_master"

parameter name doesn''t exists

cmbName.Items.Add(dr("name"))

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