我无法理解为什么我的一个组合框显示过滤搜索但另一个没有,我对两个组合框使用相同的代码,但修改了一些链接到我的数据库的 SQL 查询。我还注意到,当我删除或注释掉任何一个组合框的代码时,过滤的搜索会发生在没有被注释或删除的组合框中。我还使用了“If, Else”语句,但仍然不起作用。我还希望两个组合框都用于过滤数据网格视图。请记住,一旦从组合框中选择了项目,就会按下搜索按钮以将数据过滤/显示到 datagridview 中。
亲切的问候
这是我的代码和表格:
[显示的冗余数据] https://i.stack.imgur.com/JEQI4.png
[ComboBox 品牌按预期工作] https://i.stack.imgur.com/6YyBf.png
[ComboBox 类别显示所有内容,而不是显示选择的类别] https://i.stack.imgur.com/oEfII.png
Private Sub BtnSearch_Click(sender As Object, e As EventArgs) Handles BtnSearch.Click
If Not CmbBrand.SelectedIndex & CmbCategory.SelectedIndex = Nothing Then
BrandDisplay()
ElseIf CmbBrand.SelectedIndex & Not CmbCategory.SelectedIndex = Nothing Then
CategoryDisplay()
ElseIf Not CmbBrand.SelectedIndex & Not CmbCategory.SelectedIndex = Nothing Then
If DbConnect() Then
DgvRecord.Rows.Clear()
Dim SQLCmd As New OleDbCommand
With SQLCmd
.Connection = cn
.CommandText = "Select * " &
"From TblStock " &
"Where STCategory Like @CategorySearch"
.Parameters.AddWithValue("@CategorySearch", "%" & CmbCategory.Text & "%")
Dim rs As OleDbDataReader = .ExecuteReader()
SQLCmd.ExecuteReader()
While rs.Read
Dim NewStockRow As New DataGridViewRow()
NewStockRow.CreateCells(DgvRecord)
NewStockRow.SetValues({rs("StockID"), rs("STDateTime"), rs("STCategory"), rs("STBrand"), rs("STItemDescription"), rs("STSerialNumber"), rs("StockIn"), rs("StockOut"), rs("Stock")})
NewStockRow.Tag = rs("StockID")
DgvRecord.Rows.Add(NewStockRow)
End While
rs.Close()
If DgvRecord.Rows(0).Selected = True Then
MessageBox.Show("Please select a Category from the drop down list", "Category", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
End If
End With
End If
End If
cn.Close()
End Sub
Private Sub BrandDisplay()
If DbConnect() Then
DgvRecord.Rows.Clear()
Dim SQLCmd As New OleDbCommand
With SQLCmd
.Connection = cn
.CommandText = "Select * " &
"From TblStock " &
"Where STBrand Like @BrandSearch"
.Parameters.AddWithValue("@BrandSearch", "%" & CmbBrand.Text & "%")
Dim rs As OleDbDataReader = .ExecuteReader()
SQLCmd.ExecuteReader()
While rs.Read
Dim NewStockRow As New DataGridViewRow()
NewStockRow.CreateCells(DgvRecord)
NewStockRow.SetValues({rs("StockID"), rs("STDateTime"), rs("STCategory"), rs("STBrand"), rs("STItemDescription"), rs("STSerialNumber"), rs("StockIn"), rs("StockOut"), rs("Stock")})
NewStockRow.Tag = rs("StockID")
DgvRecord.Rows.Add(NewStockRow)
End While
rs.Close()
If DgvRecord.Rows(0).Selected = True Then
MessageBox.Show("Please select a Brand from the drop down list", "Brand", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
End If
End With
End If
cn.Close()
End Sub
Private Sub CategoryDisplay()
If DbConnect() Then
DgvRecord.Rows.Clear()
Dim SQLCmd As New OleDbCommand
With SQLCmd
.Connection = cn
.CommandText = "Select * " &
"From TblStock " &
"Where STCategory Like @CategorySearch"
.Parameters.AddWithValue("@CategorySearch", "%" & CmbCategory.Text & "%")
Dim rs As OleDbDataReader = .ExecuteReader()
SQLCmd.ExecuteReader()
While rs.Read
Dim NewStockRow As New DataGridViewRow()
NewStockRow.CreateCells(DgvRecord)
NewStockRow.SetValues({rs("StockID"), rs("STDateTime"), rs("STCategory"), rs("STBrand"), rs("STItemDescription"), rs("STSerialNumber"), rs("StockIn"), rs("StockOut"), rs("Stock")})
NewStockRow.Tag = rs("StockID")
DgvRecord.Rows.Add(NewStockRow)
End While
rs.Close()
If DgvRecord.Rows(0).Selected = True Then
MessageBox.Show("Please select a Category from the drop down list", "Category", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
End If
End With
End If
cn.Close()
End Sub
```