通过从其他组合框中选择值来填充组合框

Question

我收到以下错误， 我的代码是：

Private Sub Cmb_name_final_SelectedIndexChanged(sender As Object, e As EventArgs)  
     Handles Cmb_name_final.SelectedIndexChanged

    Cbofill(dsetreg, "select* from Student_info where ID=" & 
          Me.Cmb_name_final.SelectedValue & "", Me.Cmb_reg_final, 
         "Student_registration", "ID")

End Sub

给出错误：

Operator '&' is not defined for string "select* from Student_info where " and type 'DataRowView'.

Answer 1

您应该显示CboFill() 方法的代码以提供更完整的问题。

但是，您的问题只是您试图将字符串 ("select *...") 与 DataRowView (Me.Cmb_name_final.SelectedValue) 连接起来。

更新您的代码以访问包含您要查询的值的 DataRowView 列，并且您应该超越此错误。类似DirectCast(Me.Cmb_name_final.SelectedValue, DataRowView)("ID")。

整个事情可能看起来像这样：

Private Sub Cmb_name_final_SelectedIndexChanged(sender As Object, e As EventArgs) Handles Cmb_name_final.SelectedIndexChanged 
    Cbofill(dsetreg, "select* from Student_info where ID="& DirectCast(Me.Cmb_name_final.SelectedValue, DataRowView)("ID") &"", Me.Cmb_reg_final, "Student_registration", "ID") 
End Sub