0

这是当前的源代码：

var xhttp = new XMLHttpRequest();
  
function passVars(var1, var2, var3) {
  if (var1.readyState == 4) {
    if (var1.status == 200) {
      var data = var1.responseText;

      if (data) {
        playSuccess();
        classSwitch(data, var2, var3);
      } else {
        playFailure();
        alert("Error: returned status code " + var1.status + " " + var1.statusText);
      }
    }
  }
}
  
xhttp.onreadystatechange = function() { 
  passVars(xhttp, "tab", "p1234");
};

xhttp.open("POST", "index.php", true);
xhttp.send(formData); //formdata is a POST send to PHP's backend which returns responseText = 0 or 1 for var data

function classSwitch(state, sOrigin, stateButtonID) {
  if (sOrigin === "tab") {
    Monitored = state;
    if (state === "1") {
      if (document.getElementById("setmonitoring").classList.contains("productmonitoringdisabled")) {
        document.getElementById("setmonitoring").classList.remove("productmonitoringdisabled");
      }
      document.getElementById("setmonitoring").classList.add("productmonitoringenabled");
    }
    
    if (state === "0")  {
      if (document.getElementById("setmonitoring").classList.contains("productmonitoringenabled")) {
        document.getElementById("setmonitoring").classList.remove("productmonitoringenabled");
      }
      document.getElementById("setmonitoring").classList.add("productmonitoringdisabled");
    }
  }
  
  if (sOrigin === "issues") {
    if (state === "1") {
      if (document.getElementById(stateButtonID).classList.contains("productmonitoringdisabled")) {
        document.getElementById(stateButtonID).classList.remove("productmonitoringdisabled");
      } else document.getElementById(stateButtonID).classList.add("productmonitoringenabled");
    }
    
    if (state === "0")  {
      if (document.getElementById(stateButtonID).classList.contains("productmonitoringenabled")) {
        document.getElementById(stateButtonID).classList.remove("productmonitoringenabled");
      } else document.getElementById(stateButtonID).classList.add("productmonitoringdisabled");
    }
  }
}

var2尝试了很多方法来通过它们，主要使用 SO anwsers并且每次var2都使用undefined. 这用于库存控制系统，早期的 alpha 版本。这个想法是在后端返回产品的当前监控状态时传递元素的 id 来更改按钮类

任何想法如何传递这些变量？提前致谢

4

2 回答 2

0

下面是一个如何将参数传递给onreadystatechange回调函数的最小示例。你有点过于复杂了 - 也没有必要将你的xhttp变量传递给回调，因为它已经在范围内可用。

const xhr = new XMLHttpRequest();
xhr.open("GET", "https://developer.mozilla.org/");
xhr.send();
xhr.onreadystatechange = function() {
  callback("tab", "1234");
};


function callback(var1, var2) {
  console.log(`var1 = ${var1}`);
  console.log(`var2 = ${var2}`);

  //Do your xhr.readyState and xhr.status checks in this function
  console.log(`xhr.readyState = ${xhr.readyState}`);
  console.log(`xhr.status = ${xhr.status}`);
}

于 2021-03-04T00:36:24.383 回答
-1

你的结构不好。你不能像这样在异步调用中传递 xhttp 。直接改成这样...

xhttp.onreadystatechange = function() { 

  if (xhttp.readyState == 4) {

    if (xhttp.status == 200) {

      var data = xhttp.responseText;

      if (data) {

        playSuccess();

        classSwitch(data, 'tab', '1234');

      } else {

        playFailure();

        alert("Error: returned status code " + xhttp.status + " " + xhttp.statusText);
      }
    }
  }

};
于 2021-03-04T00:06:03.633 回答