Question

我得到以下错误，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，您的问题只是您尝试将字符串（"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，您应该超越此错误。类似于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

通过从其他组合框中选择值来填充组合框

1 个答案: