如何防止两次Page_Load Running - Page.IsPostBack总是false
本文关键字：Page Running Load IsPostBack false 总是 两次 何防止 | 更新日期: 2023-09-27 18:14:23
在一个奇怪的情况下，我的page_Load运行了两次，我所有的代码都在page_Load。
我不能使用Page.IsPostBac，因为在两个Page_Loads中，它都是假的。
但什么是奇怪的情况?
在我的项目中有一个下载文件的页面，
当你点击一个下载链接(我使用锚，所以IsPostBack是假的)page_Load运行，在页面加载我检查下载路径Querystring。
如果DownloadPath不为空，它跳转到一个处理程序。通过传递DownloadPath来显示下载窗口给我的用户。
在此过程中，我的数据库中有一些日志，由于两次运行，它们将是重复的。
但是当两次运行帐目时呢?当你尝试通过互联网下载管理器下载链接时，page_Load运行两次!
我怎么能防止page_Load的第二次运行或有一种方法来识别它?
编辑:
my page_Load:
namespace NiceFileExplorer.en
{
public partial class Download : System.Web.UI.Page
{
public string Folders = "";
public string Files = "";
protected void Page_Load(object sender, EventArgs e)
{
Statistics_body_inside.DataBind();
if (Request.QueryString["Path"] != null)
{
if (Request.QueryString["Path"] == "..")
{
ScriptManager.RegisterStartupScript(this.Page, typeof(Page), "YouCanNotDoThatAnyMore", "YouCanNotDoThatAnyMore();", true);
}
else
{
MainCodes();
}
}
else
{
MainCodes();
}
}
private void MainCodes()
{
if (Request.QueryString["DownloadPath"] != null)
{
string DownloadPath = Request.QueryString["DownloadPath"].ToString();
string FilePath = "C:" + DownloadPath.Replace(@"/", @"''");
if (Session["User_ID"] != null)
{
string FileName = Request.QueryString["FileName"].ToString();
string FileSize = Request.QueryString["FileSize"].ToString();
string FileCreationDate = Request.QueryString["FileCreationDate"].ToString();
int Downloaded_Count_4Today = DataLayer.Download.Count_By_UserID_Today(int.Parse(HttpContext.Current.Session["User_ID"].ToString()), DateTime.Now);
if (Downloaded_Count_4Today <= 10)
{
DataSet dsDownload = DataLayer.Download.Size_By_UserID_Today(int.Parse(HttpContext.Current.Session["User_ID"].ToString()), DateTime.Now);
if (dsDownload.Tables["Download"].Rows.Count > 0)
{
DataRow drDownload = dsDownload.Tables["Download"].Rows[0];
int SumOfFileSize4Today = int.Parse(drDownload["FileSizSum"].ToString());
if (SumOfFileSize4Today + int.Parse(FileSize) <= 1073741824)//1 GB = 1024*1024*1024 bytes = 1073741824 bytes
//if (SumOfFileSize4Today + int.Parse(FileSize) <= 100000)
{
//DataLayer.Download.InsertRow(
// int.Parse(Session["User_ID"].ToString()),
// DateTime.Now,
// FilePath.Replace(@"''", @"'"),
// FileName,
// FileSize,
// DateTime.Parse(FileCreationDate)
// );
Response.Redirect("~/HandlerForMyFE.ashx?Downloadpath=" + HttpUtility.UrlEncode(DownloadPath));
}
else
{
ScriptManager.RegisterStartupScript(this.Page, typeof(Page), "YouCanNotDownloadAnyMore_SizeOverload", "YouCanNotDownloadAnyMore_SizeOverload();", true);
}
}
else
{
if (int.Parse(FileSize) <= 1073741824)
//if (int.Parse(FileSize) <= 100000)
{
//DataLayer.Download.InsertRow(
// int.Parse(Session["User_ID"].ToString()),
// DateTime.Now,
// FilePath.Replace(@"''", @"'"),
// FileName,
// FileSize,
// DateTime.Parse(FileCreationDate)
// );
Response.Redirect("~/HandlerForMyFE.ashx?Downloadpath=" + HttpUtility.UrlEncode(DownloadPath));
}
else
{
ScriptManager.RegisterStartupScript(this.Page, typeof(Page), "YouCanNotDownloadAnyMore_SizeOverload", "YouCanNotDownloadAnyMore_SizeOverload();", true);
}
}
}
else
{
ScriptManager.RegisterStartupScript(this.Page, typeof(Page), "YouCanNotDownloadAnyMore_CountOverload", "YouCanNotDownloadAnyMore_CountOverload();", true);
}
}
else
{
ScriptManager.RegisterStartupScript(this.Page, typeof(Page), "plzLoginFirst_ForDownload", "plzLoginFirst_ForDownload();", true);
}
}
DirectoryInfo dir;
string lastpath = "";
try
{
lastpath = Request["path"].ToString();
}
catch { }
lblTitleInHeader.Text = "Files";
lblTitleInHeader.Text += lastpath;
//set back
string[] splited = lblTitleInHeader.Text.Split('/');
lblTitleInHeader.Text = "";
ArrayList arName = new ArrayList();
for (int i = 0; i < splited.Length; i++)
{
if (splited[i] != "")
{
arName.Add(splited[i]);
}
}
for (int i = 0; i < arName.Count - 1; i++)
{
if (i != arName.Count - 1)
{
lblTitleInHeader.Text += "<a href='Download.aspx?path=%2f";//%2f = /
for (int j = 1; j < i + 1; j++)
{
lblTitleInHeader.Text += HttpUtility.UrlEncode(arName[j].ToString() + "/");
}
lblTitleInHeader.Text += "'>" + arName[i] + "</a>" + " " + "<img class='icoSubFolder' src='../Images/Download/icoSubFolder.png' />";
}
}
lblTitleInHeader.Text += arName[arName.Count - 1].ToString();
lblTitleInHeader.Text = lblTitleInHeader.Text.Replace("/'>", "'>");
if (lastpath != "")
{
//dir = new DirectoryInfo(Server.MapPath("~/Files/" + lastpath));
dir = new DirectoryInfo(@"C:''Files''" + lastpath.Replace(@"/", @"''"));
}
else
{
//dir = new DirectoryInfo(Server.MapPath("~/Files/"));
dir = new DirectoryInfo(@"C:''Files''");
}
int count4Folders = 0;
foreach (DirectoryInfo d in dir.GetDirectories())
{
count4Folders++;
DirectoryInfo dirSub = new DirectoryInfo(d.FullName);
int iDir = 0;
int iFile = 0;
foreach (DirectoryInfo subd in dirSub.GetDirectories())
{
iDir++;
}
foreach (FileInfo f in dirSub.GetFiles("*.*"))
{
iFile++;
}
Folders += "<div class='divFoldersBody_Row'>";
Folders += "<div class='divFoldersBody_Left'>";
Folders += " ";
Folders += "</div>";
Folders += "<div class='divFoldersBody_Name'>";
Folders += "<span class='imgFolderContainer'><img class='imgFolder' src='../Images/Download/folder.png' /></span>";
Folders += "<span class='FolderName'><a class='FolderLink' href='Download.aspx?path=" + HttpUtility.UrlEncode(lastpath + "/" + d.Name) + "'>";
Folders += d.Name;
Folders += "</a></span>";
Folders += "</div>";
Folders += "<div class='divFoldersBody_Count'>";
Folders += iDir.ToString() + " Folders & " + iFile.ToString() + " Files";
Folders += "</div>";
Folders += "<div class='divFoldersBody_Right'>";
Folders += " ";
Folders += "</div>";
Folders += "</div>";
}
if (count4Folders == 0)
{
divFoldersHeader.Style.Add("display", "none");
}
int count4Files = 0;
foreach (FileInfo f in dir.GetFiles("*.*"))
{
count4Files++;
Files += "<div class='divFilesBody_Row'>";
Files += "<div class='divFilesBody_Left'>";
Files += " ";
Files += "</div>";
Files += "<div class='divFilesBody_Name'>";
char[] Extension_ChAr = f.Extension.ToCharArray();
string Extension_str = string.Empty;
int lenghth = Extension_ChAr.Length;
for (int i = 1; i < Extension_ChAr.Length; i++)
{
Extension_str += Extension_ChAr[i];
}
if (Extension_str.ToLower() == "rar" || Extension_str.ToLower() == "zip" || Extension_str.ToLower() == "zipx" || Extension_str.ToLower() == "7z" || Extension_str.ToLower() == "cat")
{
Files += "<span class='imgFileContainer'><img class='imgFile-rar' src='../Images/Download/file-rar.png' /></span>";
}
else if (Extension_str.ToLower() == "txt" || Extension_str.ToLower() == "doc" || Extension_str.ToLower() == "docx")
{
Files += "<span class='imgFileContainer'><img class='imgFile-txt' src='../Images/Download/file-txt.png' /></span>";
}
else if (Extension_str.ToLower() == "pdf")
{
Files += "<span class='imgFileContainer'><img class='imgFile-pdf' src='../Images/Download/file-pdf.png' /></span>";
}
else if (Extension_str.ToLower() == "jpg" || (Extension_str.ToLower() == "png") || (Extension_str.ToLower() == "gif") || (Extension_str.ToLower() == "bmp") || (Extension_str.ToLower() == "psd"))
{
Files += "<span class='imgFileContainer'><img class='imgFile-image' src='../Images/Download/file-image.png' /></span>";
}
else if (Extension_str.ToLower() == "exe")
{
Files += "<span class='imgFileContainer'><img class='imgFile-exe' src='../Images/Download/file-exe.png' /></span>";
}
else
{
Files += "<span class='imgFileContainer'><img class='imgFile-unknown' src='../Images/Download/file-unknown.png' /></span>";
}
Files += "<span title='" + f.Name + "' class='FileName'>";
Files += f.Name;
Files += "</span>";
Files += "</div>";
Files += "<div class='divFilesBody_FileType'>";
Files += "<span style='color:red;'>" + Extension_str.ToUpper() + "</span>" + " File";
//Files += Path.GetExtension(f.Name) + " File";
Files += "</div>";
Files += "<div class='divFilesBody_FileSize'>";
Files += ConvertBytes.ToFileSize(long.Parse(f.Length.ToString()));
Files += "</div>";
Files += "<div class='divFilesBody_FileCreationDate'>";
Files += f.CreationTime;
Files += "</div>";
Files += "<div class='divFilesBody_FileDownload'>";
string Downloadpath = "/Files" + lastpath + "/" + f.Name;
string EncodedDownloadpath = HttpUtility.UrlEncode(Downloadpath);
Files += "<a class='FileLink' href='Download.aspx?path=" + HttpUtility.UrlEncode(lastpath) + "&Downloadpath=" + EncodedDownloadpath + "&FileName=" + HttpUtility.UrlEncode(f.Name) + "&FileSize=" + HttpUtility.UrlEncode(f.Length.ToString()) + "&FileCreationDate=" + HttpUtility.UrlEncode(f.CreationTime.ToString()) + "'>";
Files += "<img class='imgDownload' src='../Images/Download/Download.png' />";
Files += "</a>";
Files += "</div>";
Files += "<div class='divFilesBody_Right'>";
Files += " ";
Files += "</div>";
Files += "</div>";
}
if (count4Files == 0)
{
divFilesHeader.Style.Add("display", "none");
}
if ((count4Folders == 0) && (count4Files == 0))
{
divFoldersHeader.Style.Add("display", "block");
divFilesHeader.Style.Add("display", "block");
}
ScriptManager.RegisterStartupScript(this, this.GetType(), "hash", "location.hash = '#BreadCrumbInDownload';", true);
}
....
my aspx:
<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="server">
<link href="css/Download.css" rel="stylesheet" type="text/css" />
<script type="text/javascript">
$(function () {
$('#Download-body *').css({ 'zIndex': 2 });
$('#Download-body').css({ 'overflow': 'hidden', 'position': 'relative' });
var containerWidth = $('#Download-body').innerWidth();
var containerHeight = $('#Download-body').innerHeight();
var bgimgurl = $('#Download-body').css('backgroundImage').replace(/url'(|')|"|'/g, "");
var img = $('<img src="' + bgimgurl + '" width="' + containerWidth + 'px"' + ' height="' + containerHeight + 'px" />').css({ 'position': 'absolute', 'left': 0, 'top': 0, 'zIndex': 1 });
$('#Download-body').css({ 'background': 'transparent' }).append(img);
});
</script>
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
<div id="Download">
<div id="Download-header">
<div id="DownloadTitle">
Download
</div>
<asp:Image ID="imgDownload_header_left" runat="server" ImageUrl="~/Images/Download-header-left.png" />
<asp:Image ID="imgDownload_header_right" runat="server" ImageUrl="~/Images/Download-header-right.png" />
</div>
<div id="Download-body">
<div id="Download-body-inside">
<div id="Statistics">
<div id="Statistics-header">
<div id="StatisticsTitle">
Statistics
</div>
<asp:Image ID="imgStatistics_header_left" runat="server" ImageUrl="~/Images/Statistics-header-left.png" />
<asp:Image ID="imgStatistics_header_right" runat="server" ImageUrl="~/Images/Statistics-header-right.png" />
</div>
<div id="Statistics-body">
<div runat="server" id="Statistics_body_inside">
<asp:Label ID="lblDownload_Count_By_UserID_Title" runat="server" Text="Ur Download Count :"
ToolTip="Your Download Count From The Begining Of Registration UpTo Now" CssClass="lblTitleInStatistics"></asp:Label>
<asp:Label ID="lblDownload_Count_By_UserID" runat="server" Text="<%# Download_Count_By_UserID() %>"
CssClass="lblCountInStatistics"></asp:Label>
<br />
<asp:Label ID="lblDownload_Count_By_UserID_Today_Title" runat="server" Text="Ur Download Count-Today :"
ToolTip="Your Download Count-Today" CssClass="lblTitleInStatistics"></asp:Label>
<asp:Label ID="lblDownload_Count_By_UserID_Today" runat="server" Text="<%# Download_Count_By_UserID_Today() %>"
CssClass="lblCountInStatistics"></asp:Label>
<br />
<asp:Label ID="lblDownload_Size_By_UserID_Title" runat="server" Text="Ur Download Size :"
ToolTip="Your Download Size From The Begining Of Registration UpTo Now" CssClass="lblTitleInStatistics"></asp:Label>
<asp:Label ID="lblDownload_Size_By_UserID" runat="server" Text="<%# Download_Size_By_UserID() %>"
CssClass="lblCountInStatistics"></asp:Label>
<br />
<asp:Label ID="lblDownload_Size_By_UserID_Today_Title" runat="server" Text="Ur Download Size-Today :"
ToolTip="Your Download Size-Today" CssClass="lblTitleInStatistics"></asp:Label>
<asp:Label ID="lblDownload_Size_By_UserID_Today" runat="server" Text="<%# Download_Size_By_UserID_Today() %>"
CssClass="lblCountInStatistics"></asp:Label>
<br />
<asp:Label ID="lblDownload_Size_By_UserID_Today_Remain_Title" runat="server" Text="Ur Remain Download Size-Today :"
ToolTip="Your Remain Download Size-Today" CssClass="lblTitleInStatistics"></asp:Label>
<asp:Label ID="lblDownload_Size_By_UserID_Today_Remain" runat="server" Text="<%# Download_Size_By_UserID_Today_Remain() %>"
CssClass="lblCountInStatistics"></asp:Label>
</div>
</div>
</div>
<div id="MainDivInDownload">
<div id="BreadCrumbInDownload">
<div id="imgicoHomeContainer">
<asp:Image ID="imgicoHome" runat="server" ImageUrl="~/Images/Download/icoHome.png" />
</div>
<div id="lblTitleInHeaderContainer">
<asp:Label ID="lblTitleInHeader" runat="server" Text=""></asp:Label>
</div>
<div style="clear: both;">
</div>
</div>
<div runat="server" id="divFolders">
<div runat="server" id="divFoldersHeader">
<div id="divFoldersHeader_Left">
<asp:Image ID="divFoldersHeader_imgLeft" runat="server" ImageUrl="~/Images/Download/divsHeader_Left.png" />
</div>
<div id="divFoldersHeader_Name">
Folders In This Folder
</div>
<div id="divFoldersHeader_Count">
Total Files In This Folder
</div>
<div id="divFoldersHeader_Right">
<asp:Image ID="divFoldersHeader_imgRight" runat="server" ImageUrl="~/Images/Download/divsHeader_Right.png" />
</div>
</div>
<div id="divFoldersBody">
<%-- <div class="divFoldersBody_Row">
<div class="divFoldersBody_Left">
</div>
<div class="divFoldersBody_Name">
<span class="imgFolderContainer">
<asp:Image CssClass="imgFolder" runat="server" ImageUrl="~/Images/Download/folder.png" />
</span><span class="FolderName"><a class="FolderLink" href="#">Folders In This Folder</a></span>
</div>
<div class="divFoldersBody_Count">
Total Files In This Folder
</div>
<div class="divFoldersBody_Right">
</div>
</div>--%>
<%= Folders %>
</div>
</div>
<div runat="server" id="divFiles">
<div runat="server" id="divFilesHeader">
<div id="divFilesHeader_Left">
<asp:Image ID="divFilesHeader_imgLeft" runat="server" ImageUrl="~/Images/Download/divsHeader_Left.png" />
</div>
<div id="divFilesHeader_Name">
Files In This Folder
</div>
<div id="divFilesHeader_FileType">
File Type
</div>
<div id="divFilesHeader_FileSize">
File Size
</div>
<div id="divFilesHeader_FileCreationDate">
File Creation Date
</div>
<div id="divFilesHeader_FileDownload">
</div>
<div id="divFilesHeader_Right">
<asp:Image ID="divFilesHeader_imgRight" runat="server" ImageUrl="~/Images/Download/divsHeader_Right.png" />
</div>
</div>
<div id="divFilesBody">
<%-- <div class="divFilesBody_Row">
<div class="divFilesBody_Left">
</div>
<div class="divFilesBody_Name">
<span class="imgFileContainer">
<asp:Image runat="server" ImageUrl="~/Images/Download/file.png" CssClass="imgFile" />
</span><span class="FileName">Files In This Folder</span>
</div>
<div class="divFilesBody_FileType">
File Type
</div>
<div class="divFilesBody_FileSize">
File Size
</div>
<div class="divFilesBody_FileCreationDate">
File Creation Date
</div>
<div class="divFilesBody_FileDownload">
<a class="FileLink" href="#">
<asp:Image CssClass="imgDownload" runat="server" ImageUrl="~/Images/Download.png" />
</a>
</div>
<div class="divFilesBody_Right">
</div>
</div>--%>
<%= Files %>
</div>
</div>
</div>
</div>
</div>
</div>
</asp:Content>
thanks in advance
请查看在页面上呈现的html:
每当它出现
<img src=""/>
双回发可以发生，对于某些浏览器…
如果这就是问题所在，你可以为每个按钮设置一个默认的空白图像
<asp:ImageButton ImageUrl="~/Images/blank.gif"...