Question

我正在尝试使用相同类型/父级的多个精灵节点，但是当我尝试生成另一个节点时，我收到错误。 'NSInvalidArgumentException'，原因：'尝试添加已有父级的SKNode'

这是我的代码：

<form action="" method="post" enctype="multipart/form-data"> 
            <table align="center" width="700" >
                <tr align="center">
                    <td  colspan="5"><h2>SHOPPING CART</h2></td>
                </tr>
                <tr align="center">
                    <th>Remove</th>
                    <th>Product (s)</th>
                    <th>Quantity</th>
                    <th> Price</th>
                    <th> Total Price</th>
                </tr>

                <?php 

                global $con;
        $total = 0;
        $ip = getIp();


        $sel_price = "select * from cart where  ip_add='$ip'";

        $run_price = mysqli_query($con,$sel_price);

        while($p_price = mysqli_fetch_array($run_price)){

            $pro_id = $p_price['p_id'];

            $pro_price = "select * from products where product_id = '$pro_id'";

            $run_pro_price = mysqli_query($con, $pro_price);

            while($pp_price = mysqli_fetch_array($run_pro_price)){
                $product_price = array($pp_price['product_price']);

                $product_id = $pp_price['product_id'];
                $product_title = $pp_price['product_title'];
                $product_image = $pp_price['product_image'];

                $single_price = $pp_price['product_price'];

                $values = array_sum($product_price);

                $total += $values;

                ?>
            <tr align = "center">
                <td><input type="checkbox" name="remove[]" value=" <?php  global $con; echo $pro_id; ?>"/></td>
                <td><span style="color: white;"><?php echo $product_title; ?></span>
                <br>
                <img src="admin_area/product_images/<?php  echo $product_image; ?>" width="100px" height="100px"></td>
                <td><input type="number" size="4" name="qty" /></td>
                <?php
                global $con;
                global $Stotal;
                $Stotal = $single_price;

                if(isset($_POST['update_quantity'])){

                    $qty = $_POST['qty'];
                    $update_qty = "update cart set qty='$qty' ";
                    $run_qty = mysqli_query($con, $update_qty);


                    $Stotal = $single_price * $qty;

                    }




                ?>
                <td><?php echo "KSh. " . $single_price; ?></td> 
                    <td><?php echo "KSh. " . $Stotal; ?></td>
            </tr>

        <?php }} ?>
        <tr align="right">
                <td colspan="5"><b>Total:</b> <?php echo "KSh. " . $total; ?></td>      
        </tr>


        <tr align="center">
            <td><input type="submit" name="update_cart" value="Update Cart" /></td>
            <td><input type="submit" name="continue" value="Continue Shopping" /></td>
            <td><input type="submit" name="update_quantity" value="Update Quantity" /></td>
            <td><button><a href="checkout.php" style="text-decoration: none; color: black;"> Checkout </a></button></td>
        </tr>
            </table>
        </form>
    <?php

        global $con;
        $ip = getIp();

        if(isset($_POST['update_cart'])){

            foreach($_POST['remove'] as $remove_id){

            $delete_pro = "delete from cart where p_id = '$remove_id' and ip_add='$ip'";

            $run_delete = mysqli_query($con, $delete_pro);

            if($run_delete){
                echo "<script>window.open('cart.php','_self')</script>";

            }
            }

        }

        if(isset($_POST['continue'])){

        echo "<script>window.open('index.php','_self')</script>";

        }


    ?>

Answer 1

您需要实例化另一个SKSpriteNode。在现有代码中，您创建一个火球并将其添加到场景中;当你尝试再次添加相同的火球时，你的程序会崩溃。

首先，删除您的let fireball = SKSpriteNode...行。将其移至spawnFireball()方法内部，如下所示：

func spawnFireball(point: CGPoint) {
    let fireball = SKSpriteNode(imageNamed: "fireball")
    //Insert all customization here (your existing code should mostly work)
    self.addChild(fireball)
}

因为fireball变量是局部变量，所以每次调用函数时都可以实例化一个新变量。现在，只需将update()方法更改为正确使用enumerateChildrenWithName()，方法是将每self.fireball更改为node。

这样，代码将遍历当前在场的每个现有火球，而不是当前的代码，只允许您创建一个火球。

SKSpriteNode无法拥有多个子节点

1 个答案: