我有一个类InjectedClass，它有一个方法someMethod。这门课需要三个参数。我需要另一个类Myclass中方法的输出。基本上，我需要通过Myclass中的构造函数将相同的三个参数传递给注入的类，因为它确实返回了一些数据。
问题是我收到一个错误，指出Myclass构造函数中的第四个参数（注入的类）应该是injectedClass的实例，但它是空的！请参见示例。
我认为问题是Injected类在没有params的情况下初始化，因此没有初始化，因此为空。此外，如果我尝试将类直接注入myfunction方法，我会得到或多或少相同的结果。我该如何解决这个烂摊子？
class Myclass {
private $var1;
private $var2;
private $var3;
private $injectedclass;
public function __construct($var1, $var2, $var3, InjectedClass $injectedclass)
{
$this->var1 = $var1;
$this->var2 = $var2;
$this->var3 = $var3;
$this->injectedclass = $injectedclass;
}
public function myfunction()
{
return $this->injectedclass($this->var1, $this->var2, $this->var3)->someMethod();
}
}
class InjectedClass {
private $var1;
private $var2;
private $var3;
public function __construct($var1, $var2, $var3)
{
$this->var1 = $var1;
$this->var2 = $var2;
$this->var3 = $var3;
}
public function someMethod()
{
// do stuff
}
}
MyClass在构造中只需要一个参数-InjectedClass instansce，它就可以工作了。即
$injected = new Injected($var1, $var2, $var);
$my = new MyClass($injected);
$my->myfunction(); // will work correctly now
我会重新思考如何尝试使用依赖项注入。我脑海中最简单的方法是在InjectedClass中创建setter，并在设置构造中的类变量时设置它们。类似于：
class Myclass {
private $var1;
private $var2;
private $var3;
private $injectedclass;
public function __construct($var1, $var2, $var3, InjectedClass $injectedclass)
{
$this->var1 = $var1;
$this->var2 = $var2;
$this->var3 = $var3;
$this->injectedclass = $injectedclass;
$this->injectedclass->setParams($this->var1, $this->var2, $this->var3);
}
public function myfunction()
{
return $this->injectedclass($this->var1, $this->var2, $this->var3)->someMethod();
}
}
class InjectedClass {
private $var1;
private $var2;
private $var3;
public function setParams($var1, $var2, $var3) {
$this->var1 = $var1;
$this->var2 = $var2;
$this->var3 = $var3;
}
public function someMethod()
{
// do stuff
}
}
当然，你可以稍微清理一下，但通过这种方式注射，你应该能够避免你面临的问题。
一切都取决于你想要实现什么，但基本上在中
public function myfunction()
{
return $this->injectedclass($this->var1, $this->var2, $this->var3)->someMethod();
}
您不需要传递这些参数，因为$this->injectedclass已经是已经初始化其属性的对象。所以代码应该是这样的：
class Myclass {
private $var1;
private $var2;
private $var3;
private $injectedclass;
public function __construct($var1, $var2, $var3, InjectedClass $injectedclass)
{
$this->var1 = $var1;
$this->var2 = $var2;
$this->var3 = $var3;
$this->injectedclass = $injectedclass;
}
public function myfunction()
{
return $this->injectedclass->someMethod();
}
}
class InjectedClass {
private $var1;
private $var2;
private $var3;
public function __construct($var1, $var2, $var3)
{
$this->var1 = $var1;
$this->var2 = $var2;
$this->var3 = $var3;
}
public function someMethod()
{
// do stuff
echo $this->var1.' '.$this->var2.' '.$this->var3."<br />";
}
}
$m = new Myclass(1,2,3, new InjectedClass(1,2,3));
$m->myFunction();
但是，正如您所看到的，当您创建Myclass实例时，您需要将参数1,2,3传递给Myclass和InjectedClass，如果这些值相同，这可能不是很方便。
因此，您可以将代码更改为：
class Myclass {
private $var1;
private $var2;
private $var3;
private $injectedclass;
public function __construct($var1, $var2, $var3, InjectedClass $injectedclass)
{
$this->var1 = $var1;
$this->var2 = $var2;
$this->var3 = $var3;
$this->injectedclass = $injectedclass;
$this->injectedclass->setParams($var1, $var2, $var3);
}
public function myfunction()
{
return $this->injectedclass->someMethod();
}
}
class InjectedClass {
private $var1;
private $var2;
private $var3;
public function setParams($var1, $var2, $var3)
{
$this->var1 = $var1;
$this->var2 = $var2;
$this->var3 = $var3;
}
public function someMethod()
{
// do stuff
echo $this->var1.' '.$this->var2.' '.$this->var3."<br />";
}
}
$m = new Myclass(1,2,3, new InjectedClass());
$m->myFunction();
所以您只将参数传递给Myclass，它将参数设置为InjectedClass。但这种方法导致即使创建InjectedClass类的对象，也需要运行setParams方法来设置参数，所以这不是最好的解决方案。
最好是：
class Myclass {
private $var1;
private $var2;
private $var3;
private $injectedclass;
public function __construct(InjectedClass $injectedclass)
{
$this->injectedclass = $injectedclass;
list ($this->var1, $this->var2, $this->var3) = $this->injectedclass->getParams();
}
public function myfunction()
{
return $this->injectedclass->someMethod();
}
}
class InjectedClass {
private $var1;
private $var2;
private $var3;
public function __construct($var1, $var2, $var3)
{
$this->var1 = $var1;
$this->var2 = $var2;
$this->var3 = $var3;
}
public function getParams() {
return array ($this->var1, $this->var2, $this->var3);
}
public function someMethod()
{
// do stuff
echo $this->var1.' '.$this->var2.' '.$this->var3."<br />";
}
}
$m = new Myclass(new InjectedClass(1,2,3));
$m->myFunction();
其中CCD_ 10的对象可以将这些参数返回给CCD_。