用全局变量控制件输入的合法性

在程序中需要控制控件输入的合法性，只有在当几个控件都有输入的情况下才开放按键的使用权。

在这里我是使用了2个全局变量，当指定控件数值发生改变时改变变量值并判断另一变量的值，当条件满足时开放按键的使用权。

 

Public Class f_sale
    Dim check_quantity, check_price As Integer

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim mdi_sale_customer As New f_sale_customer
        mdi_sale_customer.MdiParent = f_start
        mdi_sale_customer.Show()
        Button1.Enabled = False

    End Sub

 

    。。。。。。。。。。。。。。。。

 

  Private Sub f_sale_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        'unenable the buttons which can bring errors
        bu_sale_addnew.Enabled = False
        bu_sale_finish.Enabled = False
        bu_sale_save.Enabled = False
        inptex_sale_buyer.Visible = False
        check_price = 0
        check_quantity = 0  ‘ 注意要在load中给变量赋初始值

。。。。。。

    Private Sub bu_sale_addnew_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles             bu_sale_addnew.Click
        tex_sale_salebak_comid.Text = combo_sale_commodity_comid.Text
        tex_sale_salebak_cost.Text = tex_sale_cost.Text
        'table.salebak addnew
        bu_sale_cancle.Enabled = True
        Binding_sale_salebak.EndEdit()
        OleDb_sale_salebak.Update(DataSet_sale_salebak1)
        Binding_sale_salebak.AddNew()
        bu_sale_addnew.Enabled = False
        bu_sale_save.Enabled = False
        bu_sale_finish.Enabled = False
        combo_sale_commodity_comid.Enabled = True
        check_price = 0
        check_quantity = 0   ’’ 在合适的位置还要对初始值进行重置

 

 

    End Sub

 

。。。。。。。。。

 

    Private Sub tex_sale_quan_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tex_sale_quan.TextChanged

        tex_sale_salebak_quan.Text = tex_sale_quan.Text
        check_quantity = 1
        If check_price = 1 Then
            bu_sale_addnew.Enabled = True
            bu_sale_save.Enabled = True
        End If

    End Sub

。。。。。。

    Private Sub tex_sale_salebak_price_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tex_sale_salebak_price.TextChanged
        check_price = 1
        If check_quantity = 1 Then
            bu_sale_addnew.Enabled = True
            bu_sale_save.Enabled = True
        End If      ‘‘ 这2段是对全局变量进行赋值，以记录控件输入情况，当1是为已输入，0是未输入。当1个变量为1时判断另一变量是否为1，如也为1则条件满足，开放按键的使用权。
    End Sub