Android学习——Fragment动态加载
动态加载原理
利用FragmentManager来添加一套Fragment事务,最后通过commit提交该事务来执行对Fragment的相关操作。
FragmentManager fragmentmanager = getFragmentManager();
FragmentTransaction beginTransaction = fragmentmanager.beginTranaction();
具体步骤
1.创建Fragment类
public class Fragment2 extends Fragment { private TextView tv; @Nullable @Override public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { View view=inflater.inflate(R.layout.fragment_1,container,false); tv= (TextView) view.findViewById(R.id.textview); tv.setText("动态加载"); return view; } }
2.在Activity中启用事务
mbutton2.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { Fragment2 fragment2=new Fragment2(); android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager(); android.support.v4.app.FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction(); fragmentTransaction.add(R.id.frame,fragment2); fragmentTransaction.commit(); } });
需要注意的是,由于Android Studio中Activity默认继承AppCompatActivity,所以在申请FragmentManager时,需要用getSupportFragmentManager()方法来获取。
3.利用addToBackStack实现回退功能
addToBackStack方法可以实现点击返回键时,回到上一个Fragment状态的效果。