帮助Onclick Vb.Net-创建要单击的代码. [英] Help Onclick Vb.Net - Create code to click.

问题描述

帮我创建要单击的代码.

<输入类型=按钮" id ="ppp0"值=断开连接" name ="wanAct" onclick ="wanConnectAct(" ppp0，``disconnect")">

VB.NET

Help me create code to click.

<input type = "button" id = "ppp0" value = "Disconnect" name = "wanAct" onclick = "wanConnectAct (''ppp0'', ''disconnect'')">

VB.NET

推荐答案

问题是您无法通过尝试传递这两个参数的原因很简单:第一个参数(如果使用)始终为event，它传递事件对象，在这种情况下为鼠标事件:
https://developer.mozilla.org/en-US/docs/Web/API/MouseEvent [ ^ ].

如果将元素更改为此，则可以利用您的技术:

The problem is that you cannot pass these two arguments as you are trying it, by one simple reason: the first argument, if used, is always event, which passes the event object, in this case, the mouse event:
https://developer.mozilla.org/en-US/docs/Web/API/MouseEvent[^].

You can utilize your technique if you change your element to this:

<input type = "button" id = "ppp0" value = "Disconnect" name = "wanAct" onclick = "wanConnectAct (event, 'ppp0', 'disconnect')">

如果以这种方式进行操作，并且在JavaScript中正确定义了点击处理程序，它将可以正常工作:

If you do it this way, it will work, if you define your click handler in JavaScript properly:

function wanConnectAct(
   eventObject, // event information will be passed (mouse coordinates, etc.)
   id, // "ppp0" will be passed
   value) // { "" will be passed
      // ...
}

在此函数内部，您可以使用id标识按钮对象(请参见下文)，但这并不是必需的，因为您已经传递了value.同时，您似乎尝试使用该值来标识操作的类型.如果是这样，这是错误的方法，不利于维护.这是魔术字" 反模式.显然，您必须在多个地方写这个词，这将破坏代码的可维护性.如果只在一个地方拼错了怎么办?很难检测到.请参阅: http://en.wikipedia.org/wiki/Don%27t_repeat_yourself [

Inside this function, you can identify the button object using the id (see below), but it is hardly needed, because you already passed the value. At the same time, it looks like you try to use the value to identify the type of action. If so, this is wrong approach, bad for maintenance. This is the "magic word" anti-pattern. Apparently, you have to write this word in more than one place, which will break the maintainability of your code. What if you misspell it in just one place? It will be hard to detect. Please see: http://en.wikipedia.org/wiki/Don%27t_repeat_yourself[^].

A different (simpler?) approach is to add the event handler in JavaScript. In this way, you won''t need anything to identify your button object or any other target:

myButton = document.getElementById("ppp0");
// already identified, now use the object reference:
myButton.onclick = function() {
    // do whatever you want;
    // can call here any other (named) function
    // and pass any arguments
}

仅记住，您必须在body加载事件(onload事件属性)的处理程序中调用此代码，以及所有其他获得DOM对象引用并添加事件处理程序(以及更多)的代码. />
在这种方法中，您无需使用按钮的value来标识操作；和纯JavaScript.然后，您可以在功能上简单到枚举类型的对象中定义所有动作，并在所有位置使用它，而不是魔术词，而是引用该对象成员.该对象可能类似于

Only remember that you have to call this code in the handler of the body load event (onload event attribute), as well as all other code getting DOM object references and adding event handlers (and a lot more).

In this approach, you don''t need to use the value of button to identify the action; and pure JavaScript. Then you can define all action in an object functionally simple to enumeration type and use it everywhere, referring to this object members, instead of magic words. This object could be something like

var actions = {connect: 1, disconnect: 2, somethingElse: 3}

即使出现一些错误，代码也将更易于支持.

—SA

Even in case of some bugs, the code will be much easier to support.

—SA

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