ASP.NET 下载文件并继续执行JS解决方法

时间：2021-10-27 07:02:55

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); },);

    }

    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 id="form1" runat="server">

    <div>

        <asp:Button ID="Button1" runat="server" Text="Button" UseSubmitBehavior="false" OnClientClick="disable_out(this);"/>

        <asp:Button ID="Button2" 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()

        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 id="form1" 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

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