如何实现web页面的提示保存功能
每每听到客户抱怨自己修改和很久的数据由于自己的一个误操作而丢失时，总想让web页面也有像window窗体一样具有提示保存的功能。
所以，经过一段时间的研究以后终于实现了这个功能！
＝＝＝＝＝＝＝＝＝＝＝＝ checksave.js ＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
<!-- The JavaScript is used in show a message to prompt user to save data.-->
<script language="JScript">
function window::onbeforeunload(){
if (typeof(document.all['txtCheckFlag']) != "undefined") // to detect whether this page need prompt the save message!
{ if (event.clientY<0 && event.clientX>document.body.clientWidth-20
|| event.clientY<0 && event.clientX<20
|| event.altKey
|| event.clientY>document.body.clientHeight)
event.returnValue="If you have modified some data, you need push the save button to save them.\nDo you want to save?";
}
}
</script>
<script language=javascript>
<!--
function checksave(arg){
if (typeof(document.all['txtCheckFlag']) != "undefined") // to detect whether this page need prompt the save message!
{ // If need
document.all["txtCheckFlag"].value=arg;
document.forms(0).submit();
return false;
}
else // If does not need
{
window.location=arg;
return true;
}
}
function showsavemessage(arg)
{
if (window.confirm("Save Change?"))
{
document.all["txtSave"].value="1";
document.forms(0).submit();
return false;
}
else
{
if (arg == ".")
{
return true;
}
else
{
window.location=arg;
return false;
}
}
}
//-->
</script>
＝＝＝＝＝＝＝＝ test.aspx ＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
<%@ Page Language="vb" AutoEventWireup="false" Codebehind="test.aspx.vb" Inherits="Test.test" smartNavigation="True" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<title>test</title>
<meta content="Microsoft Visual Studio.NET 7.0" name="GENERATOR">
<meta content="Visual Basic 7.0" name="CODE_LANGUAGE">
<meta content="JavaScript" name="vs_defaultClientScript">
<meta content="http://schemas.microsoft.com/intellisense/ie5" name="vs_targetSchema">
<!--#include file="checksave.js"-->
</HEAD>
<body MS_POSITIONING="GridLayout" onload="pageload()">
<form id="Form1" method="post" runat="server">
<a onclick="javascript:return checksave(this.href)" href="TestNoNeedCheck.aspx">sohu</a><BR>
<a onclick="javascript:return checksave(this.href)" href="TestNoNeedCheck.aspx">yahoo</a><BR>
<a onclick="javascript:return checksave(this.href)" href="TestNoNeedCheck.aspx">MTR</a>
<asp:textbox id="txtCheckFlag" style="Z-INDEX: 101; LEFT: 213px; POSITION: absolute; TOP: 91px" runat="server"></asp:textbox><asp:textbox id="txtSave" style="Z-INDEX: 102; LEFT: 211px; POSITION: absolute; TOP: 139px" runat="server"></asp:textbox><asp:linkbutton id="LinkButton1" style="Z-INDEX: 103; LEFT: 150px; POSITION: absolute; TOP: 204px" runat="server">LinkButton</asp:linkbutton>
<asp:Button id="Button1" style="Z-INDEX: 104; LEFT: 238px; POSITION: absolute; TOP: 271px" runat="server" Text="Button"></asp:Button></form>
</body>
</HTML>
＝＝＝＝＝＝＝＝ test.aspx.vb ＝＝＝＝＝＝＝＝＝＝＝＝＝＝＝
Public Class test
Inherits System.Web.UI.Page
Protected WithEvents txtSave As System.Web.UI.WebControls.TextBox
Protected WithEvents LinkButton1 As System.Web.UI.WebControls.LinkButton
Protected WithEvents Button1 As System.Web.UI.WebControls.Button
Protected WithEvents txtCheckFlag As System.Web.UI.WebControls.TextBox
#Region " Web Form Designer Generated Code "
'This call is required by the Web Form Designer.
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
End Sub
Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init
'CODEGEN: This method call is required by the Web Form Designer
'Do not modify it using the code editor.
InitializeComponent()
End Sub
#End Region
Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'Put user code to initialize the page here
txtSave.Style.Item("display") = "none"
txtCheckFlag.Style.Item("display") = "none"
LinkButton1.Attributes("onclick") = "javascript:return checksave(this.href)"
'
Page.RegisterStartupScript("Prompt", "<script language=""javascript"">function pageload() { }</script>")
End Sub
Private Sub txtCheckFlag_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtCheckFlag.TextChanged
Session("URL") = txtCheckFlag.Text
If checkdata() Then
'Session("Data") = Me.Data
If InStr(txtCheckFlag.Text, "__doPostBack") > 0 Then
Page.RegisterStartupScript("warning", "<script language=""javascript"">function pageload() {if (showsavemessage('.')) " + Session("URL") + ";}</script>")
Else
Page.RegisterStartupScript("warning", "<script language=""javascript"">function pageload() {showsavemessage('" + Session("URL") + "');}</script>")
End If
Else
If InStr(txtCheckFlag.Text, "__doPostBack") > 0 Then
Session("URL") = Replace(txtCheckFlag.Text, "javascript:", "")
Page.RegisterStartupScript("warning", "<script language=""javascript"">function pageload() {" + Session("URL") + ";}</script>")
Else
If InStr(txtCheckFlag.Text, "javascript:") > 0 Then
Session("URL") = Replace(txtCheckFlag.Text, "javascript:", "")
Page.RegisterStartupScript("Redirect", "<script language=""javascript"">function pageload() {" + Session("URL") + ";}</script>")
Else
Page.RegisterStartupScript("Redirect", "<script language=""javascript"">function pageload() {window.location='" + Session("URL") + "';}</script>")
Response.End()
End If
End If
End If
End Sub
Private Sub txtSave_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtSave.TextChanged
If savedata() = False Then
txtSave.Text = ""
txtCheckFlag.Text = ""
Exit Sub
End If
Me.ViewState("flag") = True
If InStr(txtCheckFlag.Text, "__doPostBack") > 0 Then
Page.RegisterStartupScript("TxtSave", "<script language=""javascript"">" + Session("URL") + "</script>")
Else
If InStr(txtCheckFlag.Text, "javascript:") > 0 Then
Session("URL") = Replace(txtCheckFlag.Text, "javascript:", "")
Page.RegisterStartupScript("TxtSave", "<script language=""javascript"">function pageload() {" + Session("URL") + ";}</script>")
Else
Page.RegisterStartupScript("Redirect", "<script language=""javascript"">function pageload() {window.location='" + Session("URL") + "';}</script>")
'Response.Redirect(Session("URL"))
'Response.End()
End If
End If
txtSave.Text = ""
txtCheckFlag.Text = ""
End Sub
Private Function checkdata() As Boolean
'check whether user really had modified the data
Return True
End Function
Private Function savedata() As Boolean
'do save data here!
Return True
End Function
Private Sub LinkButton1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles LinkButton1.Click
If Me.ViewState("flag") = True Then
Page.RegisterStartupScript("Redict", "<script language=""javascript"">function pageload() {window.location='TestNoNeedCheck.aspx';}</script>")
Else
Page.RegisterStartupScript("Redict", "<script language=""javascript"">function pageload() {window.location='TestNoNeedCheck.aspx';}</script>")
End If
End Sub
End Class
