如何在全局变量中存储值，这个全局变量来自OnChange到我的AJAX脚本?

I am trying to store this.value user wrote in eMailTxt box in a Global Variable and then let AJAX do the checking of User exists or not.

我想把它存起来。value user在全局变量的eMailTxt框中写入，然后让AJAX检查用户是否存在。

HTML

Passing value onChange to ValidUser

将值onChange传递给ValidUser

<input type="text" name="eMailTxt" id="eMailTxt" onChange="ValidUser(this.value)" />

AJAX##

Checks if value exists in database through php

通过php检查数据库中是否存在值

function ValidUser(str)
{
   //Want to declare a global variable here
    if (window.XMLHttpRequest)
    {
        xmlhttp=new XMLHttpRequest();
    }
    else
    {
        xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
    }
    xmlhttp.onreadystatechange=function()
    {
        if (xmlhttp.readyState==4 && xmlhttp.status==200)
        {
            if (xmlhttp.responseText=="false")
            {
                $("#eMailTxt").css({'background-color':'#fed3da','color':'red'});
                $("#eMailTxt").val("[User Does Not Exist]"); //Changes text if user does not exist
  //Want to store str in global variable so that in $("#eMailTxt").focus function I can store back what was written earlier
            }
            else
            {
                $("#eMailTxt").css({'background-color':'#d3fef3'});
            }
        }
    }
    xmlhttp.open("GET","loginVerify.php?q="+str,true);
    xmlhttp.send();
}

4 个解决方案

#1

Add this before your function like,

在你的函数之前加上这个，

var myStr=''
function ValidUser(str)
{
   myStr=str; //Add this for assigning previous value in myStr variable
   ....

Also , if you are using ajax then use $.ajax function for this,

此外，如果您正在使用ajax，那么请使用$。ajax函数,

var myStr='';
function ValidUser(str)
{
    myStr=str;
    $.ajax({
      url:'loginVerify.php',
      type:'GET',
      data:{q:str},
      success:function(response){
          $("#eMailTxt").css({'background-color':'#fed3da','color':'red'});
          $("#eMailTxt").val("[User Does Not Exist]");
      }
    });
}

#2

Try this:

试试这个:

var eMailTxtVal = '';

function ValidUser(str)
{
    eMailTxtVal = str;

    $.get("loginVerify.php?q=" + str, function(data) {
        if (data == "false") {
            $("#eMailTxt").css({'background-color': '#fed3da', 'color': 'red'});
            $("#eMailTxt").val("[User Does Not Exist]"); //Changes text if user does not exist
        }
        else {
            $("#eMailTxt").css({'background-color': '#d3fef3'});
        }
    });
}

$("#eMailTxt").focus(function() {
    $(this).val(eMailTxtVal);
});

#3

you might need this thing. not mentioning var will make it global

你可能需要这个东西。不提及var将使它成为全球性的

myStr='';
ValidUser = function(str)
{
myStr= str;
}

#4

Just declare the variable "above" the scope of any of your functions. Set it before you change it and then recall it when you need it.

只要将变量“上面”声明为函数的范围即可。在更改它之前设置它，然后在需要时回忆它。

#1