ASP.NET 下载文件并继续执行JS解决方法

需求说明:当用户点击按钮时使当前按钮为不可用,并打开新页面,关闭新页面时,按钮变为可用。并且如果不关闭新页面,当前按钮过10秒钟自动变为可用。

包含3个页面:

一、按钮页

前台代码:当刷新后采用js进行disable后,点击的时候也可以用JS使其为disable,让整个过程都disable。(如果采用的是后台button.Enable=false,则不行,因为服务器端状态始终为false,导致按钮只能用一次。)

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default2.aspx.vb" Inherits="Default2" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>
<script  type="text/javascript" language="javascript">

    function disableButton(button) {
        var btn = document.getElementById(button);
        setTimeout(function () {disable_in(btn); },10000);
    }
    function disable_in(button)
    {
    button.disabled=false;
}
function Enablebutton(buttonID) {
    var button = document.getElementById(buttonID);
    button.disabled = false;
}
    function NotEnablebutton(buttonID) {
        var button = document.getElementById(buttonID);
        button.disabled = true;
    }

    function disable_out(button) {
        button.disabled = true;
    }

//    function disableButton_Out(button) {
//        setTimeout(function () { disable_out(button); }, 50);
//    }

</script>
    <form  runat="server">
    <div>
        <asp:Button  runat="server" Text="Button" UseSubmitBehavior="false" OnClientClick="disable_out(this);"/>
        <asp:Button  runat="server" Text="Button2" UseSubmitBehavior="false" OnClientClick="disable_out(this);"/>
    </div>
    </form>
</body>
</html>

后台代码:

这里用服务器端 Button1.Enabled = False代码, 当用JS还原为可用时,服务器端状态不会改变,因此多个按钮点击时会出现bug(点击第二个按钮时,第一个按钮会一起变为不可用)。所以这里将用js设置为不可用状态。

 Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
        Session("ImagePath") = "\\129.223.229.102\Dis_project\Temp\test.pdf"
        'Session("ImagePath") = "\\129.223.229.102\Dis_project\Temp\test1.zip"
        Session("CurrentButtonID") = Button1.ClientID
        Session("IsPDF") = True
        System.Threading.Thread.Sleep(100)
        ClientScript.RegisterStartupScript(ClientScript.GetType(), "myscript1", String.Format("<script>disableButton('" & Button1.ClientID & "')</script>"))
ClientScript.RegisterStartupScript(ClientScript.GetType(), "myscript2", String.Format("<script>NotEnablebutton('" & Button1.ClientID & "');</script>")) ClientScript.RegisterStartupScript(ClientScript.GetType(), "myscript", String.Format("<script>window.open('ShowPDF.aspx')</script>")) 'Button1.Attributes.Add("OnClientClick", String.Format("javascript:disableButton_Out(this);")) 'Button1.Enabled = False End Sub

二、下载(显示)页面

前台代码:

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="ShowPDF.aspx.vb" Inherits="ShowPDF" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>ShowPDF</title>
</head>
<body>
    <form  runat="server">
    
   <%--<script  type="text/javascript" language="javascript">
            window.onbeforeunload = closingCode;
            function closingCode() {
                opener.Enablebutton();
            }

</script>--%>
        <%--<% GetPDF1()%>--%>
        <iframe  src="Default3.aspx" width="100%" height="100%">
        </iframe>
    </form>
</body>
</html>

后台代码:

Imports System.Net
Partial Class ShowPDF
    Inherits System.Web.UI.Page
    
    Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim js As String = ""
        Dim buttonid As String = ""
        If Not Session("ImagePath") Is Nothing AndAlso Not Session("CurrentButtonID") Is Nothing Then
            buttonid = Session("CurrentButtonID").ToString()
            js = "<script>window.onbeforeunload = closingCode;function closingCode() {opener.Enablebutton('" + buttonid + "');}</script>"
            'js = String.Format("<script>window.onbeforeunload = closingCode;function closingCode() {opener.Enablebutton('{0}');}</script>", "Button1")
            Response.Write(js) 'write the enable parent button'js
        End If

    End Sub
    Public Sub ShowPDFfile()
        Dim str As String = ""
        If Not Session("ImagePath") Is Nothing Then
            str = String.Format("<object data=""\\129.223.229.102\Dis_project\Temp\test.pdf"" type=""application/pdf"" width=""100%"" height=""100%""><p>It appears you don't have a PDF plugin for this browser.No biggie... you can <a href=""em.pdf"">click here todownload the PDF file.</a></p></object>")
        End If
        Response.Write(str)
    End Sub

    Public Sub GetPDF(ByVal path As String)
        'Dim path As String = Server.MapPath(Spath)
        Dim client As New WebClient()
        Dim buffer As [Byte]() = client.DownloadData(path)

        If buffer IsNot Nothing Then
            Response.ContentType = "application/pdf"
            Response.AddHeader("content-length", buffer.Length.ToString())
            Response.BinaryWrite(buffer)
            Response.Flush()
            Response.End()
        End If
    End Sub
    Protected Sub DownloadFile(ByVal fileName As String)
        '20110905 Test Export with SSL using IE 7
        Dim s_path As String = fileName 'HttpContext.Current.Server.MapPath("~/") +
        Dim file As System.IO.FileInfo = New System.IO.FileInfo(s_path)

        Response.ClearHeaders()

        HttpContext.Current.Response.ContentType = "application/ms-download"
        HttpContext.Current.Response.Charset = "utf-8"
        Response.AddHeader("Content-Disposition", "inline; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8)) 'inline
        HttpContext.Current.Response.AddHeader("Content-Length", file.Length.ToString())
        Response.AddHeader("Pragma", "public")
        Response.AddHeader("Cache-Control", "max-age=0")
        Response.Flush()
        HttpContext.Current.Response.WriteFile(file.FullName)
        HttpContext.Current.Response.Flush()
        'HttpContext.Current.Response.Clear()
        HttpContext.Current.Response.End()

    End Sub
    Public Sub GetPDF1()
        Dim fileName As String = "\\129.223.229.102\Dis_project\Temp\test1.pdf"
        Response.ContentType = "application/pdf"
        Response.Clear()
        Response.TransmitFile(fileName)
        Response.End()
    End Sub
End Class

三、框架中的真正的下载(显示页面),显示在框架中

前台代码:

后台代码:

 Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

        Dim fileName As String = ""
        If Not IsPostBack Then
            If Not Session("ImagePath") Is Nothing AndAlso Not Session("CurrentButtonID") Is Nothing Then
                fileName = Session("ImagePath").ToString()
                GetPDF1(fileName)
            End If

        End If

    End Sub
    Public Sub GetPDF1(ByVal fileName As String)
        'Dim fileName As String = "\\129.223.229.102\Dis_project\Temp\test1.pdf"

        If Session("IsPDF") = False Then
            Response.ContentType = "application/zip"
            Response.AddHeader("Content-Disposition", "attachment; filename=" + HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8))
        Else
            Response.ContentType = "application/pdf"
        End If
        Response.Clear()
        Response.TransmitFile(fileName)
        Response.End()
    End Sub