我如何在JavaScript中检查的IsPostBack？ [英] How can I check for IsPostBack in JavaScript?

问题描述

我需要运行JavaScript函数的onLoad（），但只有这样做，如果网页加载在第一时间（即不是回发的结果）。

I need to run a JavaScript function onLoad(), but only do it if the page loaded the first time (i.e. is not the result of a postback).

基本上，我需要在JavaScript中检查的IsPostBack。

Basically, I need to check for IsPostBack in JavaScript.

感谢您。

推荐答案

服务器端，写：

if(IsPostBack)
{
   // NOTE: the following uses an overload of RegisterClientScriptBlock() 
   // that will surround our string with the needed script tags 
   ClientScript.RegisterClientScriptBlock(GetType(), "IsPostBack", "var isPostBack = true;", true);
}

然后，在你的脚本为运行在onLoad，检查该变量是否存在：

Then, in your script which runs for the onLoad, check for the existence of that variable:

if(isPostBack) {
   // do your thing
}

---

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您并不真正需要，否则设置变量，像乔纳森的解决方案。客户端if语句将正常工作，因为的IsPostBack变量将是不确定的，这在计算结果为假的if语句。

You don't really need to set the variable otherwise, like Jonathan's solution. The client-side if statement will work fine because the "isPostBack" variable will be undefined, which evaluates as false in that if statement.

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