<Fragment>的生命周期

来源：互联网发布：中国联通无线上网 mac 编辑：程序博客网时间：2024/06/07 05:33

坚持住你的坚持，成功就在拐弯处。

/** * 生命周期的代码 */public class LifecycleFragment extends Fragment {    public static final String TAG = "LifecycleFragment";    @Override    public void onAttach(Context context) {        super.onAttach(context);        Log.d(TAG, "--onAttach--");    }    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        Log.d(TAG, "--onCreate--");    }    @Override    public View onCreateView(LayoutInflater inflater, ViewGroup container,                             Bundle savedInstanceState) {        Log.d(TAG, "--onCreateView--");        TextView tv = new TextView(getActivity());        tv.setText("测试 fragment");        tv.setGravity(Gravity.CENTER);        tv.setTextSize(36);        return tv;    }    @Override    public void onActivityCreated(Bundle savedInstanceState) {        super.onActivityCreated(savedInstanceState);        Log.d(TAG, "--onActivityCreated--");    }    @Override    public void onStart() {        super.onStart();        Log.d(TAG, "--onStart--");    }    @Override    public void onResume() {        super.onResume();        Log.d(TAG, "--onResume--");    }    @Override    public void onPause() {        super.onPause();        Log.d(TAG, "--onPause--");    }    @Override    public void onStop() {        super.onStop();        Log.d(TAG, "--onStop--");    }    @Override    public void onDestroyView() {        super.onDestroyView();        Log.d(TAG, "--onDestroyView--");    }    @Override    public void onDestroy() {        super.onDestroy();        Log.d(TAG, "--onDestroy--");    }    @Override    public void onDetach() {        super.onDetach();        Log.d(TAG, "--onDetach--");    }    public LifecycleFragment() {    }}

package com.test.lifecyclefragment.activity;import android.content.Intent;import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.Button;import com.test.lifecyclefragment.R;import com.test.lifecyclefragment.fragment.LifecycleFragment;import com.test.lifecyclefragment.fragment.SeconFragment;/** * Fragment的生命周期 * */public class MainActivity extends AppCompatActivity {    Button startActivity,addFragment,backFragment,replaceFragment,finish;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initView(); //初始化控件        initListener(); //初始化监听事件    }    private void initListener() {        startActivity.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                //启动对话框风格Activity                startActivity(new Intent(MainActivity.this,SecondActivity.class));            }        });        //添加 Fragment        addFragment.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                LifecycleFragment fragment = new LifecycleFragment();                getFragmentManager().beginTransaction().replace(R.id.container,fragment).commit();            }        });        //将替换前的Fragment 添加到 Back栈中        backFragment.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                SeconFragment secFragment = new SeconFragment();                getFragmentManager().beginTransaction()                        .replace(R.id.container, secFragment)                        .addToBackStack("aa")// 将替换前的Fragment添加到Back栈                        .commit();            }        });        //替换 Fragment        replaceFragment.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                SeconFragment secFragment = new SeconFragment();                getFragmentManager().beginTransaction().replace(R.id.container, secFragment).commit();            }        });        // 为finish按钮绑定事件监听器        finish.setOnClickListener(new View.OnClickListener()        {            @Override            public void onClick(View source)            {                // 结束该Activity                MainActivity.this.finish();            }        });    }    private void initView() {        startActivity = (Button) findViewById(R.id.start_dialog_activity);        addFragment = (Button) findViewById(R.id.addFragment);        backFragment = (Button) findViewById(R.id.backFragment);        replaceFragment = (Button) findViewById(R.id.replaceFragment);        finish = (Button) findViewById(R.id.finish);    }}

/** * 对话框风格 Activity */public class SecondActivity extends Activity {    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        TextView tv = new TextView(getApplication());        tv.setText("对话框风格Activity");        setContentView(tv);    }}

public class SeconFragment extends Fragment{    @Nullable    @Override    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {        TextView tv = new TextView(getActivity());        tv.setText("第二个 Fragment");        tv.setGravity(Gravity.CENTER_HORIZONTAL);        tv.setTextSize(36);        tv.setTextColor(Color.BLUE);        return  tv;    }}

点击加载目标Fragment 按钮时会执行 –onAttach–,–onCreate–, –onCreateView–,–onActivityCreated–,–onStart–,-onResume–方法.
接着点击启动对话框Activity的按钮当前的Activity会进入暂停状态,该 Fragment也会进入暂停状态,会执行 –onPause–方法. 点击返回键,关闭对话框Activity. Fragment会执行onResume()方法.

继续点击替换目标Fragment,并加入Back栈中的按钮
–onPause– –onStop– –onDestroyView–方法.

点击替换目标Fragment 按钮之后执行 –onPause–, –onStop–,–onDestroyView–, –onDestroy–,–onDetach– 该Fragment 将会被完全结束,Fragment将进入”销毁”状态.

Fragment 的生命周期中,如下方法被系统回调.

onAttach(Activity) 当Fragment被添加到 Activity时,被回调.该方法只会被调用一次.
onCreate(Bundle) 创建Fragment 时被回调,该方法只会被调用一次.
onCreateView(LayoutInflater, ViewGroup, Bundle) ;每次创建,绘制Fragment的View组件时回调该方法,Fragment将会显示该方法返回的view组件.
onActivityCreated(Bundle) 当Fragment所在的Activity 被启动完成后回调该方法.
onStart() 启动Fragment 时被回调.
onResume() 恢复Fragment时被回调, onStart()方法后一定会回调 onResume()方法.
onPause() 暂停时Fragment时被回调.
onStop(); 停止Fragment 时被回调.
onDestroyView() 销毁该Fragment 所包含的View 组件时调用.
onDestroy() 销毁 Fragment时被回调. 该方法只会调用一次.
onDetach() 将该 fragment 从Activity中被删除,被替换完成时,回调该方法. onDestroy方法后一定会回调 onDetach()方法.该方法只会调用一次.

0 0