如果下拉列表等于1，则禁用耦合输入区域

Question

我在php页面上遇到了这个问题。选择下拉后，我无法禁用3个输入区域

我只想禁用不相关的输入区域，如果滑块的类型选择像1，否则什么都不做

将用于条件的HTML代码：

<div class="form-group">
<label for="slider_type">Slider Type</label>
<select name="slider_type" class="form-select" id="slider_type" required>
<option value="" disabled selected>Please Select</option>
<option value="1">Image</option>
<option value="2">Video</option>
</select>
</div>

如果slider_type等于1 ，我想禁用的HTML代码

<label for="slider_title">Slider Title</label>
<input type="text" name="slider_title" id="slider_title" class="form-control round" placeholder="Slider Title" onchange="DisableSliderInputArea()" required>
</div>
</div>
<div class="col-md-6 mb-4">
<div class="form-group">
<label for="slider_description">Slider Body</label>
<input type="text" name="slider_description" id="slider_description" class="form-control round" placeholder="Slider Body" required>
</div>
</div>
<div class="col-md-6 mb-4">
<div class="form-group">
<label for="slider_button_link">Slider Button Link</label>
<input type="text" name="slider_button_link" id="slider_button_link" class="form-control round" placeholder="Slider Button Link" required>
</div>
</div>

我尝试了1个输入区域的JavaScript代码行，但它不起作用

<script type="text/javascript">
function DisableSliderInputArea(){

if(document.getElementById("slider_type").value=="1"){
document.getElementById("slider_title").disabled = true;
} else {
document.getElementById("slider_title").disabled = false;
} 

} 
</script>

到底出了什么问题？

Answer 1

您几乎完成了所有的工作，缺少的一件事是，一旦您的选择框更改了其值，就会实际调用函数DisableSliderInputArea。您需要添加一个事件侦听器，因此一旦用户更改所选选项，您的功能就会被触发，并且文本区域将被禁用或启用

请随意运行下面的代码片段，看看它是如何工作的。我在JS部分添加了您需要添加的行的注释。

function DisableSliderInputArea() {
if (document.getElementById("slider_type").value == "1") {
document.getElementById("slider_title").disabled = true;
} else {
document.getElementById("slider_title").disabled = false;
}
}
// Get the select out of the DOM and store in a local variable
const dropdown = document.getElementById("slider_type");
// Attach an event listener, so once the select changes
// its' value, this function will be called
dropdown.addEventListener("change", DisableSliderInputArea);

<div class="form-group">
<label for="slider_type">Slider Type</label>
<select name="slider_type" class="form-select" id="slider_type" required>
<option value="" disabled selected>Please Select</option>
<option value="1">Image</option>
<option value="2">Video</option>
</select>
</div>
<label for="slider_title">Slider Title</label>
<input type="text" name="slider_title" id="slider_title" class="form-control round" placeholder="Slider Title" onchange="DisableSliderInputArea()" required>
</div>
</div>
<div class="col-md-6 mb-4">
<div class="form-group">
<label for="slider_description">Slider Body</label>
<input type="text" name="slider_description" id="slider_description" class="form-control round" placeholder="Slider Body" required>
</div>
</div>
<div class="col-md-6 mb-4">
<div class="form-group">
<label for="slider_button_link">Slider Button Link</label>
<input type="text" name="slider_button_link" id="slider_button_link" class="form-control round" placeholder="Slider Button Link" required>
</div>
</div>

Answer 2

您几乎完成了，只是错误地将onchange设置为"DisableSliderInputArea((">

function DisableSliderInputArea(){
if(document.getElementById("slider_type").value=="1"){
document.getElementById("slider_title").disabled = true;
} else {
document.getElementById("slider_title").disabled = false;
} 

}

<div class="form-group">
<label for="slider_type">Slider Type</label>
<select name="slider_type" class="form-select" id="slider_type" onchange="DisableSliderInputArea()" required>
<option value="" disabled selected>Please Select</option>
<option value="1">Image</option>
<option value="2">Video</option>
</select>
</div>
<label for="slider_title">Slider Title</label>
<input type="text" name="slider_title" id="slider_title" class="form-control round" placeholder="Slider Title" required>
<div class="col-md-6 mb-4">
<div class="form-group">
<label for="slider_description">Slider Body</label>
<input type="text" name="slider_description" id="slider_description" class="form-control round" placeholder="Slider Body" required>
</div>
</div>
<div class="col-md-6 mb-4">
<div class="form-group">
<label for="slider_button_link">Slider Button Link</label>
<input type="text" name="slider_button_link" id="slider_button_link" class="form-control round" placeholder="Slider Button Link" required>
</div>
</div>