从后面的代码（C#）中设置 javascript 变量的值
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Setting value for javascript variable from code behind (C#)
提问by Christian Mark
I understand the difference between Client-side and Server-side scripting. I have a javascript function and variable in my MasterPage:
我了解客户端和服务器端脚本之间的区别。我有一个 javascript 函数和变量MasterPage：
<script language="JavaScript" type="text/javascript">
var needToConfirm = false;
window.onbeforeunload = confirmExit;
function confirmExit()
{
if (needToConfirm)
{
needToConfirm = false;
return "Currently in edit mode. If you leave the page now then you will lose unsaved changes."
}
}
</script>
Given the fact that on my ASP.NET (Client-side) I can change the value of my needToConfirmvariable to trueonClientClickbut by default it is false. Here's an example.
鉴于在我的 ASP.NET（客户端）上，我可以将needToConfirm变量的值更改为，trueonClientClick但默认情况下它是 false。这是一个例子。
<asp:Button ID="btnEdit" runat="server" Text=" Edit " onclick="btnEdit_Click" OnClientClick="needToConfirm = true;" />
Now the question here is when on the C# (Server-side) I have to set the needToConfirmto true under an if-statementbut not necessarily on Page_Load:
现在这里的问题是在 C#（服务器端）上我必须needToConfirm在 an 下设置为 trueif-statement但不一定在Page_Load：
private void SetDefault()
if (Session[def.ID_CUST] != null)
{
//I want to change the variable value here
}
}
Thanks.
谢谢。
UPDATE
更新
I'm using .NET 2.0 Classic and WebForms
我正在使用 .NET 2.0 Classic 和 WebForms
采纳答案by Vond Ritz
in code behind:
在后面的代码中：
ScriptManager.RegisterStartupScript(this, this.GetType(), "", "urFunction('urValHere');", true);
on client-side:
在客户端：
function urFunction(urParam) {
//do what u want here
//use urParam
}
回答by Semih Yagcioglu
You can use a hidden input and then set this input to trueor falsefrom the server side.
您可以使用隐藏输入，然后将此输入设置为服务器端true或false从服务器端设置此输入。
On the client side:
在客户端：
<input type="hidden" id="hdnConfirm" runat="server" value="false"/>
Then on the server side:
然后在服务器端：
if (Session[def.ID_CUST] != null)
{
//I want to change the variable value here
hdnConfirm.Value = "true";
}
Then on the client side:
然后在客户端：
var needToConfirm = $('#hdnConfirm').val();
回答by Steven V
If I understand this correctly, you could register a client script like in the example at http://msdn.microsoft.com/en-us/library/z9h4dk8y.aspx.
如果我理解正确，您可以像http://msdn.microsoft.com/en-us/library/z9h4dk8y.aspx 上的示例一样注册一个客户端脚本。
ClientScriptManager cs = Page.ClientScript;
if (!cs.IsStartupScriptRegistered(this.GetType(), "EditMode")) {
cs.RegisterStartupScript(this.GetType(), "EditMode", "needToConfirm = true;", true);
}
That would write a script to the page setting the value of needToConfirmin Javascript.
这会将脚本写入页面，needToConfirm在 Javascript 中设置 的值。
回答by LouD
Based on your update saying it's .NET 2.0, this is how you can set a javascript variable:
根据您的更新说它是 .NET 2.0，您可以通过以下方式设置 javascript 变量：
Page.RegisterStartupScript("SetVar", "var needToConfirm = true;");
http://msdn.microsoft.com/en-us/library/system.web.ui.page.registerstartupscript(v=vs.80).aspx
http://msdn.microsoft.com/en-us/library/system.web.ui.page.registerstartupscript(v=vs.80).aspx
回答by Todd Vance
Just for reference. Here is the 4.5 way to do something like this:
仅供参考。这是执行此类操作的 4.5 方法：
// Define the name and type of the client scripts on the page.
const String csname1 = "MyScriptName";
Type cstype = this.GetType();
// Get a ClientScriptManager reference from the Page class.
ClientScriptManager cs = Page.ClientScript;
// Check to see if the startup script is already registered.
if (!cs.IsStartupScriptRegistered(cstype, csname1))
{
StringBuilder cstext1 = new StringBuilder();
cstext1.Append("<script> var myVariable = true; </");
cstext1.Append("script>");
cs.RegisterStartupScript(cstype, csname1, cstext1.ToString());
}
回答by hunteroooox
Maby this helps?
玛比这有帮助吗？
<script type="text/javascript">
function test(confirm){
var needToConfirm = confirm;
window.onbeforeunload = confirmExit;
function confirmExit() {
if (needToConfirm) {
needToConfirm = false;
return "Currently in edit mode. If you leave the page now then you will lose unsaved changes."
}
}
}
</script>
<asp:Button ID="btnEdit" runat="server" Text="Edit" onclick="btnEdit_Click" OnClientClick="javascript:test(true);" />
