我想在ComboBox
中添加项目。我有两个array()
。
Dim purpose_list() As String = {"ADMISSION", "1ST", "2ND", "3RD", "4TH", "5TH", "6TH", "7TH", "8TH", "9TH", "10TH", "11TH", "12TH"}
和
Dim find_purpose = GetListOfPurpose()
函数GetListOfPurpose()
如下所示..
Private Function GetListOfPurpose() As List(Of String)
Dim Output As New List(Of String)()
Try
OpenConnection()
Dim st_roll As String = TbRoll.Text
Dim c_id As String = CmbCourse.SelectedValue
Dim cmd As New MySqlCommand
Dim qry As String = "SELECT purpose FROM fee_payment WHERE roll_no='" + st_roll + "' AND course='" + c_id + "'"
cmd.Connection = conn
cmd.CommandText = qry
Dim dr As MySqlDataReader = cmd.ExecuteReader
While dr.Read
Output.Add(dr("purpose").ToString())
End While
dr.Close()
Catch ex As Exception
MsgBox(ex.Message)
Finally
CloseConnection()
End Try
Return Output
End Function
现在,我想在strings
中找到find_purpose
,如果存在,请删除strings
,然后将其余内容添加到ComboBox
。
如果find_purpose
包含"1ST"
和"3RD"
,则ComboBox
会添加其他项目
"ADMISSION", "2ND", "4TH", "5TH", "6TH", "7TH", "8TH", "9TH", "10TH", "11TH", "12TH"
我找到This thread,但它位于php
。
我应该在VB.NET
中做什么?
答案 0 :(得分:1)
您发布的代码:
Dim purpose_list() As String = {"ADMISSION", "1ST", "2ND", "3RD", "4TH", "5TH", "6TH", "7TH", "8TH", "9TH", "10TH", "11TH", "12TH"}
Dim find_purpose = GetListOfPurpose()
Private Function GetListOfPurpose() As List(Of String)
Dim Output As New List(Of String)()
Try
OpenConnection()
Dim st_roll As String = TbRoll.Text
Dim c_id As String = CmbCourse.SelectedValue
Dim cmd As New MySqlCommand
Dim qry As String = "SELECT purpose FROM fee_payment WHERE roll_no='" + st_roll + "' AND course='" + c_id + "'"
cmd.Connection = conn
cmd.CommandText = qry
Dim dr As MySqlDataReader = cmd.ExecuteReader
While dr.Read
Output.Add(dr("purpose").ToString())
End While
dr.Close()
Catch ex As Exception
MsgBox(ex.Message)
Finally
CloseConnection()
End Try
Return Output
End Function
现在,在事件处理子程序中(或者您想要进行检查的任何地方)输入以下代码:
Dim final_list As New List(Of String)
For Each item In purpose_list
If Not(find_purpose.Contains(item)) Then
final_list.Add(item)
End If
Next
ComboBox1.Items.AddRange(final_list.ToArray())