在javascript中创建元素以设置“onchange”属性 [英] createElement in javascript to set "onchange" attribute

问题描述

  var f = document.getElementById 
我试图动态地添加一个新的输入字段（dN [+ fieldsd +]）; //创建/插入新
 el = document.createElement（input）; 
 el = f.appendChild（el）; 
 el.name =dName [+ fieldsd +]; 
 el.id =dName [+ fieldsd +]; 
 el.onchange =validation（）; 
  

我也试过setAttribute都不适合我。有没有办法使这项工作或解决方法？

解决方案

在JavaScript中，设置 onchange 属性是指向函数的指针，而不是实际的字符串：

  var f = document。 getElementById（dN [+ fieldsd +]）; //创建/插入新
 el = document.createElement（input）; 
 el = f.appendChild（el）; 
 el.name =dName [+ fieldsd +]; 
 el.id =dName [+ fieldsd +]; 
 el.onchange =验证; 
  

（你有一个名为 validation ）

如果您需要传递参数，请将 onchange 设置为调用验证函数的函数：

  el.onchange = function（）{
验证（param1，param2，...）; 
}; 
  

或者，如果您需要来自输入本身的信息，则可以使用 验证函数中的关键字：

  el.onchange =验证; 
 
 .... 
 
函数验证（）{
 //这是函数的上下文。在这种情况下
 //改变的元素。 
 var value = this.value; 
 
} 
  

I am trying to dynamically add a new input feild with the "onchange" attribute:

    var f = document.getElementById("dN[" + fieldsd + "]"); // create/insert new
    el = document.createElement("input");
    el = f.appendChild(el);
    el.name = "dName[" + fieldsd + "]";
    el.id = "dName[" + fieldsd + "]";
    el.onchange =  "validation()";

I have also tried setAttribute both don't work for me. Is there a way to make this work or a work around?

解决方案

In JavaScript, set the onchange property to be a pointer to a function, not an actual string:

var f = document.getElementById("dN[" + fieldsd + "]"); // create/insert new
el = document.createElement("input");
el = f.appendChild(el);
el.name = "dName[" + fieldsd + "]";
el.id = "dName[" + fieldsd + "]";
el.onchange =  validation;

(Where you have a function named validation)

If you need to pass parameters, set onchange to a function that calls the validation function:

el.onchange = function () {  
    validation(param1, param2, ...);
};

Or, if you want information from the input itself, you can use the this keyword within your validation function:

el.onchange = validation;

....

function validation() {
    // this is the "context" for the function.  In this case
    // the element that changed.
    var value = this.value;

}

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