利用GridView实现购物车功能

版权声明： https://blog.csdn.net/eds124/article/details/85262427

Partial Class Shopping
    Inherits System.Web.UI.Page
    Private sds As SqlDataSource = New SqlDataSource(Dao.ConnectionString, "select shoppingguid, goodsname, goodscode, goodsunit, goodscate, goodsprice, shoppingshuliang, goodsinserttime, goodsupdatetime from t_shopping")

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If Session("username") = Nothing Then '没有登陆就不可以访问
            Response.Redirect("~/Default.aspx") '跳转
            Return '后面的都不执行
        End If
    End Sub

    Protected Sub gv_PreRender(ByVal sender As Object, ByVal e As System.EventArgs) Handles gv.PreRender '马上呈现gv的时候触发
        Me.gv.DataKeyNames = New String() {"shoppingguid", "goodsname", "goodscode", "goodsunit", "goodscate", "goodsprice", "goodsinserttime", "goodsupdatetime"} '数据键，gridview的数据键不允许编辑
        Me.gv.AllowPaging = True '启用分页
        Me.gv.AutoGenerateDeleteButton = True '显示删除按钮
        Me.gv.AutoGenerateEditButton = True '显示编辑按钮
        Me.gv.AutoGenerateSelectButton = True '显示选择按钮
        Me.gv.AlternatingRowStyle.BackColor = Drawing.Color.AliceBlue '迭代行颜色
        Me.gv.RowStyle.BackColor = Drawing.Color.AntiqueWhite '行颜色
        Me.gv.SelectedRowStyle.BackColor = Drawing.Color.Aqua '选择行颜色
        Me.gv.EmptyDataText = "数据库表内没有数据" '数据源为空时显示的数据 
        Me.gv.DataSource = sds '选择gv的数据源
        Me.gv.DataBind() '绑定gv
    End Sub

    Protected Sub gv_RowEditing(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewEditEventArgs) Handles gv.RowEditing
        Me.gv.EditIndex = e.NewEditIndex '编辑行可用
    End Sub

    Protected Sub gv_RowCancelingEdit(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewCancelEditEventArgs) Handles gv.RowCancelingEdit
        Me.gv.EditIndex = -1 '取消编辑
    End Sub

    Protected Sub gv_RowDeleting(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewDeleteEventArgs) Handles gv.RowDeleting
        Dim shoppingguid As String = Me.gv.DataKeys(e.RowIndex).Values("shoppingguid").ToString().Trim() '如果只有一个数据键可以用这一句Me.gv.DataKeys(e.RowIndex).Value.ToString().Trim()
        sds.DeleteCommand = "delete from t_shopping where shoppingguid = @shoppingguid" '删除命令
        sds.DeleteParameters.Add("shoppingguid", shoppingguid) '参数注入（预处理）
        sds.Delete() '执行删除动作
        Me.gv.EditIndex = -1 '取消编辑
    End Sub

    Protected Sub gv_RowUpdating(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewUpdateEventArgs) Handles gv.RowUpdating
        Dim shoppingshuliang As String = CType(Me.gv.Rows(e.RowIndex).Cells(7).Controls(0), TextBox).Text.Trim().ToLower()
        Dim shoppingguid As String = Me.gv.DataKeys(e.RowIndex).Values("shoppingguid").ToString().Trim() '如果只有一个数据键可以用这一句Me.gv.DataKeys(e.RowIndex).Value.ToString().Trim()
        sds.UpdateCommand = "update t_shopping set shoppingshuliang = @shoppingshuliang where shoppingguid = @shoppingguid"
        sds.UpdateParameters.Add("shoppingshuliang", shoppingshuliang) '参数注入（预处理）
        sds.UpdateParameters.Add("shoppingguid", shoppingguid) '参数注入（预处理）
        sds.Update() '执行更新动作
        Me.gv.EditIndex = -1 '取消编辑
    End Sub

    Protected Sub gv_PageIndexChanging(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewPageEventArgs) Handles gv.PageIndexChanging
        Me.gv.PageIndex = e.NewPageIndex '分页
        Me.gv.EditIndex = -1 '取消编辑
    End Sub
End Class