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碎片的动态添加

Dream城堡

发布于 2018-12-14 07:15:32

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代码可运行

文章被收录于专栏：Spring相关Spring相关

运行总次数：0

代码可运行

碎片的动态添加

1.添加another_right_fragment.xml:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#ffff00"
    >

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:textSize="20sp"
        android:text="this is another right fragment"
        />

</LinearLayout>

2.新建AnotherRightFragment类

package com.example.fragmenttest;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class AnotherRightFragment extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater,
                             ViewGroup container, Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.another_right_fragment,
                container, false
        );
        return view;
    }
}

3.修改activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal">

    <fragment
        android:id="@+id/left_fragment"
        android:name="com.example.fragmenttest.LeftFragment"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1"></fragment>
  
    <FrameLayout
        android:id="@+id/right_layout"
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1">
    </FrameLayout>

</LinearLayout>

4.修改MainActivity

package com.example.fragmenttest;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button button = (Button) findViewById(R.id.button);
        button.setOnClickListener(this);
        //动态添加RightFragment这个碎片到当前界面
        replaceFragment(new RightFragment());

    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.button:
                //点击按钮替换为另一个碎片
                replaceFragment(new AnotherRightFragment());
                break;
            default:
                break;
        }
    }

    private void replaceFragment(Fragment fragment) {
        FragmentManager fragmentManager = getSupportFragmentManager();
        FragmentTransaction transaction = fragmentManager.beginTransaction();
        transaction.replace(R.id.right_layout, fragment);
        //添加返回栈,点击back会返回上一个界面而不是退出
        transaction.addToBackStack(null);
        transaction.commit();


    }
}

效果如下:

dfff.gif

碎片和活动之间进行通信

获取碎片实例的方法:

        LeftFragment leftFragment = (LeftFragment) getFragmentManager().findFragmentById(R.id.left_fragment);

获取活动的方法:

   MainActivity activity = (MainActivity)getActivity();

碎片的生命周期

onAttach()

当碎片和活动建立关联的时候调用。

onCreateView()

为碎片创建视图（加载布局）时调用。

onActivityCreated()

确保与碎片相关联的活动一定已经创建完毕的时候调用。

onDestroyView()

当与碎片关联的视图被移除的时候调用。

onDetach()

当碎片和活动解除关联的时候调用。

package com.example.fragmenttest;

import android.content.Context;
import android.nfc.NfcAdapter;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class RightFragment extends Fragment {

    private static final String TAG = "RightFragment";

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        Log.d(TAG, "onAttach: 当碎片和活动建立关联");
    }

    @Override
    public void onCreate( Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        Log.d(TAG, "onCreate: ");
    }

    @Override
    public View onCreateView(LayoutInflater inflater,  ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.right_fragment,
                container, false
        );

        return view;
    }


    @Override
    public void onActivityCreated(@Nullable Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
        Log.d(TAG, "onActivityCreated: 活动建立");
    }


    @Override
    public void onStart() {
        super.onStart();
        Log.d(TAG, "onStart: 开始");
    }


    @Override
    public void onResume() {
        super.onResume();
        Log.d(TAG, "onResume: 继续");
    }

    @Override
    public void onPause() {
        super.onPause();
        Log.d(TAG, "onPause: 暂停");
    }

    @Override
    public void onStop() {
        super.onStop();
        Log.d(TAG, "onStop: 停止");
    }

    @Override
    public void onDestroyView() {
        super.onDestroyView();
        Log.d(TAG, "onDestroyView: ");
    }


    @Override
    public void onDestroy() {
        super.onDestroy();
        Log.d(TAG, "onDestroy: 销毁");
    }

    @Override
    public void onDetach() {
        super.onDetach();
        Log.d(TAG, "onDetach: ");
    }
}