java - 从 .class 或类似的东西实例化 Fragment 对象？

Question

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Answer 1

要创建类的实例，可以使用反射。 获取类就像使用所有 List 实现附带的 get 方法一样简单，当然要确保您正在访问的 index 确实存在。获取类对象后，您可以使用反射来实例化它:

示例 #1，无参数构造函数:

Class<?> myClass = String.class;
        try {
            Object objectOfClass = myClass.newInstance();
        } catch (InstantiationException | IllegalAccessException e1) {
            e1.printStackTrace();
        }

示例 #2 带参数的构造函数:

    Class<?> myClass = String.class;//Get the class from the list. For this example i used String.class
    try {
        Constructor<?> classConstructor = myClass.getConstructor(byte[].class); //Here we get the constructor we aim for. String has a constructor which accepts a byte array as parameter, so all i do is getConstructor with patameter byte[].class. 
//if your class accepts two parameters such as long and int, you will have to do .getConstructor(long.class, int.class); in the correct order ofcourse. 
        Object objectOfClass = classConstructor.newInstance(new byte[]{33,25,111,34});//here we call the constructor and we provide the parameter values it takes to it. So thats why i provide a byte array. In the case of the long and int constructor mentioned above, you will have to invoke it like this: .newInstance(214324324234,34242); 
    } catch (ReflectiveOperationException e) { //Reflective operation exception wraps up all reflection related exceptions, so we catch it instead of having to manually catch each of them. 
        e.printStackTrace();
    }

编辑 #1 在评论中与 OP 交谈后，必须提供一段更具体的代码:

        // NOTE: THIS PIECE OF CODE ASUMES THAT Fragment IS THE SUPERCLASS OF ALL IMPLEMENTATIONS IN THE LIST!
    List<Class<? extends Fragment>> l = new ArrayList<>();//This is your list of fragments
    Fragment fragmentObject = (Fragment) l.get(3).newInstance();//use default constructor with no arguments. I am randomly getting index 3
    Bundle arguments = new Bundle();
    arguments.putInt("someValue",123);
    fragmentObject.setArguments(arguments);