Kotlin定义静态变量、静态方法

kotlin定义静态变量、方法可以采用伴生对象companion object的方式。

经典例子，实例化Fragment。

java写法：

public class TestFragment extends Fragment {

private static final String ARG_PARAM1 = "param1";

private static final String ARG_PARAM2 = "param2";

private String mParam1;

private String mParam2;

public TestFragment() {

}

public static TestFragment newInstance(String param1, String param2) {

TestFragment fragment = new TestFragment();

Bundle args = new Bundle();

args.putString(ARG_PARAM1, param1);

args.putString(ARG_PARAM2, param2);

fragment.setArguments(args);

return fragment;

}

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

if (getArguments() != null) {

mParam1 = getArguments().getString(ARG_PARAM1);

mParam2 = getArguments().getString(ARG_PARAM2);

}

}

@Override

public View onCreateView(LayoutInflater inflater, ViewGroup container,

Bundle savedInstanceState) {

return inflater.inflate(R.layout.fragment_test, container, false);

}

}

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kotlin写法：

class TestFragment : Fragment() {

companion object {

private val ARG_PARAM1 = "param1"

private val ARG_PARAM2 = "param2"

fun newInstance(param1: String, param2: String): TestFragment {

val fragment = TestFragment()

val args = Bundle()

args.putString(ARG_PARAM1, param1)

args.putString(ARG_PARAM2, param2)

fragment.arguments = args

return fragment

}

}

private var mParam1: String? = null

private var mParam2: String? = null

override fun onCreate(savedInstanceState: Bundle?) {

super.onCreate(savedInstanceState)

if (arguments != null) {

mParam1 = arguments!!.getString(ARG_PARAM1)

mParam2 = arguments!!.getString(ARG_PARAM2)

}

}

override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,

savedInstanceState: Bundle?): View? {

return inflater.inflate(R.layout.fragment_test, container, false)

}

}

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作者：清风徐来qfxl

来源：CSDN

原文：https://blog.csdn.net/xuyonghong1122/article/details/80268981

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