我正在尝试创建一个php脚本，该脚本从表单中获取输入值，然后在提交表单时输出建议的行程路线。我将表单方法设置为POST。问题是我得到空白输出。
我不确定问题是我的代码还是POST方法。
class Truck {
// constructor
public function __construct($truck_name, $max_weight) {
$this->truck_name = $truck_name;
$this->max_weight = $max_weight;
}
public function print_truck() {
if (isset($_POST['submit']))
{
$truck_1 = new Truck($truck_name, $max_weight);
$this->truck_name = $_POST['truck_name'];
$this->max_weight = $_POST['max_weight'];
}
echo $this->truck_name;
}
}
class Location {
// constructor
public function __construct($location_name, $location_weight) {
$this->location_name = $location_name;
$this->location_weight = $location_weight;
}
public function trip_1() {
if (isset($_POST['submit'])) {
$location_2 = new Location($location_name, $location_weight);
$this->location_name = $_POST['location_2'];
$this->location_weight = $_POST['package_2'];
$location_3 = new Location($location_name, $location_weight);
$this->location_name = $_POST['location_3'];
$this->location_weight = $_POST['package_3'];
}
echo "Trip #1 \n" . $this->location_2 . ", " . $this->location_3 . "\n";
}
public function trip_2() {
if (isset($_POST['submit'])) {
$location_1 = new Location($location_name, $location_weight);
$this->location_name = $_POST['location_1'];
$this->location_weight = $_POST['package_1'];
}
echo "Trip #2 \n" . $this->location_1;
}
}
# Here's the output HTML:
?>
<!DOCTYPE HTML>
<html lang="en">
<head>
<title>Deliveries</title>
</head>
<body class="container">
<form method="post" action="">
<input type="text" name="truck_name" Placeholder="Truck Name" value="" required>
<input type="number" name="max_weight" Placeholder="Max weight in lbs" value="" required>
<h4>Delivery Locations</h4>
<input type="text" name="location_1" Placeholder="Location 1" value="" required>
<input type="number" name="package_1" Placeholder="Package weight in lbs" value="" required>
<input type="text" name="location_1" Placeholder="Location 2" value="">
<input type="number" name="package_2" Placeholder="Package weight in lbs" value="" required>
<input type="text" name="location_1" Placeholder="Location 3" value="" required>
<input type="number" name="package_3" Placeholder="Package weight in lbs" value="" required>
<input type="submit" name="submit" value="Get Trips">
<input type="reset" name="reset" value="Reset">
</form>
<?php
if (isset($_POST['submit']))
{ ?>
<h2><?php echo "Trip Routes"; ?></h2>
<?php
$truck_1->print_truck();
trip_1();
trip_2();
}
?>
</body>
</html>
这是预期的结果：
旅行1： 位置2，位置3
旅行2： 位置1
答案 0 :(得分：0)
在尝试调用方法之前，不要实例化任何类。您需要实例化该类，例如$ truck = new truck（）;。然后从那里调用您的方法。
答案 1 :(得分：0)
正如我在评论中提到（然后删除）并指出的那样-上面的代码实际上没有多大意义。感谢您正在学习PHP，但是实例化类对象和分配值的方式不正确。在类class constructor中调用method是很重要的事情。 class应该使用任何需要的参数实例化，然后调用methods。可以将一个类作为另一个类的参数，这与我在下面创建一个名为Trip的新类并分配truck和location的实例的过程类似。 ...我可能已经错过了重点，但希望能有所帮助。
<?php
class Truck {
private $truck_name;
private $truck_weight;
public function __construct($name=false, $weight=false) {
$this->truck_name = $name;
$this->max_weight = $weight;
}
public function get_name(){
return $this->truck_name;
}
public function get_max_weight(){
return $this->max_weight;
}
}
class Location {
private $location_name;
private $location_weight;
public function __construct($name=false, $weight=false) {
$this->location_name = $name;
$this->location_weight = $weight;
}
public function get_location(){
return $this->location_name;
}
public function get_location_weight(){
return $this->location_weight;
}
}
class Trip{
private $truck;
private $locations;
public function __construct( Truck $truck, $locations=array() ){
$this->truck=$truck;
$this->locations=$locations;
}
public function display(){
if( !empty( $this->locations ) ){
$dots=str_repeat('-',25);
printf(
"<h2>Trip Routes</h2>
<pre>%s\nTruck: %s\nMax-Weight: %s\n%s\n",
$dots,
$this->truck->get_name(),
$this->truck->get_max_weight(),
$dots
);
$total_locations_weight = 0;
foreach( $this->locations as $index => $location ){
$total_locations_weight += floatval( $location->get_location_weight() );
printf(
"[Drop: %d]\nLocation: %s\nLocation-Weight: %s\n\n",
$index+1,
$location->get_location(),
$location->get_location_weight()
);
}
printf("%s</pre>",$dots);
/* Is there too much weight for the truck? */
if( $total_locations_weight > $this->truck->get_max_weight() ){
printf(
"<pre><h1 style='color:red;margin:0;'>Maximum Weight Exceded</h1><div>Total weight is: %s</div><div>Limit exceded by: %s:</div>\n%s</pre>",
$total_locations_weight,
$total_locations_weight - $this->truck->get_max_weight(),
$dots
);
}
}
}
}
?>
<!DOCTYPE HTML>
<html lang="en">
<head>
<title>Deliveries</title>
</head>
<body class="container">
<form method="post" action="">
<input type="text" name="truck_name" placeholder="Truck Name" value="" required>
<input type="number" name="max_weight" placeholder="Max weight in lbs" value="" required>
<h4>Delivery Locations</h4>
<input type="text" name="location_1" placeholder="Location 1" value="" required>
<input type="number" name="package_1" placeholder="Package weight in lbs" value="" required>
<input type="text" name="location_2" placeholder="Location 2" value="">
<input type="number" name="package_2" placeholder="Package weight in lbs" value="" required>
<input type="text" name="location_3" placeholder="Location 3" value="" required>
<input type="number" name="package_3" placeholder="Package weight in lbs" value="" required>
<input type="submit" name="submit" value="Get Trips">
<input type="reset" name="reset" value="Reset">
</form>
<?php
if( $_SERVER['REQUEST_METHOD']=='POST' && isset( $_POST['submit'] ) ){
$truck_name = filter_input( INPUT_POST, 'truck_name', FILTER_SANITIZE_STRING );
$max_weight = filter_input( INPUT_POST, 'max_weight', FILTER_SANITIZE_STRING );
$location_1 = filter_input( INPUT_POST, 'location_1', FILTER_SANITIZE_STRING );
$location_2 = filter_input( INPUT_POST, 'location_2', FILTER_SANITIZE_STRING );
$location_3 = filter_input( INPUT_POST, 'location_3', FILTER_SANITIZE_STRING );
$package_1 = filter_input( INPUT_POST, 'package_1', FILTER_SANITIZE_STRING );
$package_2 = filter_input( INPUT_POST, 'package_2', FILTER_SANITIZE_STRING );
$package_3 = filter_input( INPUT_POST, 'package_3', FILTER_SANITIZE_STRING );
$truck=new Truck( $truck_name, $max_weight );
$loc_1=new Location( $location_1, $package_1 );
$loc_2=new Location( $location_2, $package_2 );
$loc_3=new Location( $location_3, $package_3 );
$trip=new Trip( $truck, array( $loc_1, $loc_2, $loc_3 ) );
$trip->display();
}
?>
</body>
</html>
典型的输出可能是：
Trip Routes
-------------------------
Truck: The Crushinator
Max-Weight: 2500
-------------------------
[Drop: 1]
Location: London
Location-Weight: 1500
[Drop: 2]
Location: Glasgow
Location-Weight: 1500
[Drop: 3]
Location: Edinburgh
Location-Weight: 550
-------------------------
Maximum Weight Exceded
Total weight is: 3550
Limit exceded by: 1050:
-------------------------