JavaScript 中的消息框

Question

Protected Sub ListView1_ItemCommand(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.ListViewCommandEventArgs) Handles ListView1.ItemCommand
        '...vwmr for view more; atcr for add to cart
        Dim var As String = e.CommandArgument.ToString
        Dim type As String = Left(var, 4)
        Dim ItemID As String = Replace(var, type, "")
        'Dim ad As LinkButton = CType(ListView1.FindControl("addToCart"), LinkButton)
        Dim myStringVariable As String = "You need to login first before adding anything to the cart!"

        If type = "vwmr" Then     '........go to view more page....
            Dim url As String = "~/dedicatedItemPage_aspx/dedicatedItemPage.aspx?typeOfItem=" & _
                                Request.QueryString("typeOfItem") & "&itemID=" & ItemID
            Response.Redirect(url, True)

        ElseIf type = "atcr" Then     '..........add the item to the cart.....
            If User.Identity.Name = "" Then
                Response.Write("<script type='javascript'>window.alert('" + myStringVariable + "')</script>")


                '            ClientScript.RegisterStartupScript(Me.[GetType](), "myalert", _
                '"alert('" + myStringVariable + "');" + _
                '"document.location = '" + ResolveUrl("~/login.aspx") + "';", True)
                '            'MsgBox("You need to login first before adding anything to the cart!", , "")
                'Response.Write("<script>alert('Hello')</script>")
                'ServerAlert.Show()

                'ClientScript.RegisterStartupScript(Me.[GetType](), "myalert", "alert('" + myStringVariable + "');", True)

                'ad.Attributes.Add("onclick", _
                ' "return confirm('Are you sure you want to delete?');")
                'Alert.Show("You need to login first before adding anything to the cart!")
                'MessageBox1.ShowInfo("You need to login first before adding anything to the cart!", 300, 400)
                'Response.Redirect("~/login.aspx", True)

            Else
                '..........pull details from database..........
                Dim con As New SqlClient.SqlConnection("Data Source=.\SQLEXPRESS;" & _
                                               "AttachDbFilename=|DataDirectory|\database.mdf;" & _
                                               "Integrated Security=True;User Instance=True")
                Dim sql As New SqlClient.SqlCommand("SELECT * FROM " & typeOfItems & " WHERE " & _
                                                    "itemID = '" & ItemID & "'", con)
                Dim reader As SqlClient.SqlDataReader
                con.Open()
                reader = sql.ExecuteReader
                reader.Read()
                Dim itemName As String = reader.Item("itemName")
                Dim itemPrice As String = reader.Item("ourPrice")
                Dim offer As String
                If reader.Item("offer").ToString = "" Then
                    offer = ""
                Else
                    offer = reader.Item("offer")
                End If
                con.Close()
                '.......................................................

                Dim userID As String = User.Identity.Name
                Dim sCart = New cart
                If sCart.CheckIfItemPresent(userID, ItemID, itemPrice, offer) = True Then
                    Exit Sub
                End If

                Dim buyNo As String = sCart.findLatestBuyNo(userID)
                Session("buyNo") = buyNo

                Session("buyNo") = sCart.AddToCart(ItemID, itemName, itemPrice, offer, buyNo, userID)
            End If
        End If   
    End Sub

我想用 javascript alert 替换 asp.net MsgBox...我该怎么做？注释掉的行是我已经尝试过的...请帮助我...紧急。发布网站后，asp.net MsgBox 在客户端不起作用。

Answer 1

您在最后一行调用Response.Redirect("~/login.aspx", True)，这意味着警告javascript 甚至永远不会发送到客户端。要允许显示警报框，您还必须通过在警报后设置 document.location 而不是使用 Response.Redirect 在客户端上进行重定向。

像这样：

ClientScript.RegisterStartupScript(Me.[GetType](), "myalert", _
    "alert('" + myStringVariable + "');" + _
    "document.location = '" + ResolveUrl("~/login.aspx") + "';", True)

（不确定代码是否可行，我通常编写 C#）

Answer 2

不要使用Response.Redirect。它阻止执行当前页面。在 javascript 中使用 window.location.href 代替。以下是你可能会做的事情：

ClientScript.RegisterStartupScript(Me.[GetType](), "myalert",   
"alert('" + myStringVariable + "'); document.location = 'login.aspx';", True)

Answer 3

试试这个方法：

private void alert(string Msg)
{
    Response.Write("<script type='text/javascript'>window.alert('" + Msg + "')</script>");
}

如果您想要很酷的消息，请尝试link。