问题是“总价”不起作用。当我选择“提货日期”和“放货日期”时,它将在输入表单中显示值。我必须在“天数”中输入数字,然后才能计算总价格。我需要“总价”是自动计算的。我尝试了各种JavaScript事件。在这里,我将附上我的代码。希望有人能帮助我。预先感谢。
function sum() {
var txtFirstNumberValue = document.getElementById('num1').value;
var txtSecondNumberValue = document.getElementById('numdays2').value;
var result = parseInt(txtFirstNumberValue) * parseInt(txtSecondNumberValue);
if (!isNaN(result)) {
document.getElementById('num3').value = result;
}
}
function GetDays() {
var dropdt = new Date(document.getElementById("drop_date").value);
var pickdt = new Date(document.getElementById("pick_date").value);
return parseInt((dropdt - pickdt) / (24 * 3600 * 1000));
}
function cal() {
if (document.getElementById("drop_date")) {
document.getElementById("numdays2").value = GetDays();
}
}
<label for="total">Price per day:</label>
<input type="text" name="price" id="num1" onkeyup="sum();" value="3" readonly>
<div id="pickup_date">
<p><label class="form">Pickup Date:</label>
<input type="date" class="textbox" id="pick_date" name="pickup_date" onchange="cal()" /></p>
</div>
<div id="dropoff_date">
<p><label class="form">Dropoff Date:</label>
<input type="date" class="textbox" id="drop_date" name="dropoff_date" onchange="cal()" /></p>
</div>
<div id="reserve_form">
<div id="numdays"><label class="form">Number of days:</label>
<input type="text" id="numdays2" name="numdays" oninput="sum();" />
<label for="total">Total Price (RM)</label>
<input type="text" name="test" placeholder="Total Price" value="" id="num3">
我希望总价能够自动计算。
答案 0 :(得分:2)
您只需要确保在输入完整且有效时就可以调用sum
函数(或者在示例中仅为cal
)。由于您可能希望限制用户手动设置天数,因此我已经演示了如何以编程方式触发更改事件来实现此目的。当前的惯例是以编程方式将事件附加到元素上,而不是使用内联HTML5事件符号(例如“ onchange=foo
”),请参见Why are inline event handler attributes a bad idea in modern semantic HTML?
function setDate(event) {
var days = getDays();
// if the number of days is valid
if (!isNaN(days)) {
var nod = document.getElementById("numdays2");
nod.value = days;
// programmatically setting a value will not fire a change event
nod.dispatchEvent(new Event("change"));
}
}
function getDays() {
// returns NaN if either date does not hold a valid date
var dropdt = new Date(document.getElementById("drop_date").value);
var pickdt = new Date(document.getElementById("pick_date").value);
return parseInt((dropdt - pickdt) / (24 * 3600 * 1000));
}
function cal() {
var pricePerDay = document.getElementById("pricePerDay").value;
if (0 == (pricePerDay = parseInt(pricePerDay))) { return } // TODO needs to handle decimal values
document.getElementById("total").value = parseInt(document.getElementById("numdays2").value) * pricePerDay;
}
function init() {
document.getElementById("drop_date").addEventListener("change", setDate);
document.getElementById("pick_date").addEventListener("change", setDate);
document.getElementById("numdays2").addEventListener("change", cal);
}
document.addEventListener("DOMContentLoaded", init);
<label for="total">Price per day:</label>
<input type="text" name="price" id="pricePerDay" value="" placeholder="Manually enter a value">
<div id="pickup_date">
<p><label class="form">Pickup Date:</label>
<input type="date" class="textbox" id="pick_date" name="pickup_date" /></p>
</div>
<div id="dropoff_date">
<p><label class="form">Dropoff Date:</label>
<input type="date" class="textbox" id="drop_date" name="dropoff_date" /></p>
</div>
<div id="reserve_form">
<div id="numdays"><label class="form">Number of days:</label>
<!-- numdays2 is readonly to ensure the date pickers are used -->
<input type="text" id="numdays2" name="numdays" readonly placeholder="Select dates above" />
<label for="total">Total Price (RM)</label>
<input id="total" type="text" readonly name="test" placeholder="Total Price" value="" id="num3">
</div>
</div>