Fragement基础

简介: 静态创建Fragment(要先添加依赖),静态创建的意思是不用在Java代码中加载Fragment,都在Activity的主XML文件中操作绑定Fragment。

Fragement生命周期

onAttach->oncreate->onCreateView->onViewCreated->onActivityCreated->onStart->onResume


->onpause->onStop->onDestroyView->onDestroy->onDetach

package com.yyt.trackcar.ui.fragment;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.yyt.trackcar.R;
/**
 * A simple {@link Fragment} subclass.
 * Use the {@link AnalysisAMapFragment#newInstance} factory method to
 * create an instance of this fragment.
 */
public class AnalysisAMapFragment extends Fragment {
    // TODO: Rename parameter arguments, choose names that match
    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";
    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;
    public AnalysisAMapFragment() {
        // Required empty public constructor
    }
    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @param param1 Parameter 1.
     * @param param2 Parameter 2.
     * @return A new instance of fragment AnalysisAMapFragment.
     */
    // TODO: Rename and change types and number of parameters
    public static AnalysisAMapFragment newInstance(String param1, String param2) {
        AnalysisAMapFragment fragment = new AnalysisAMapFragment();
        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) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_analysis_a_map, container, false);
    }
}


静态创建Fragment(要先添加依赖)


静态创建的意思是不用在Java代码中加载Fragment


              都在Activity的主XML文件中操作绑定Fragment


1.先创建一个Fragment(和Activity一样)然后得用一个Activity承载它。在承载Fragment的Activity的XML主布局中通过name属性绑定(也可以用class="包名+类名"),然后设置id

2.然后在Fragment的XML主布局中设置布局,然后在Fragment的Java代码中找到控件并设置对应的监听事件,一般是在onViewCreated中找控件

3.设置完时候去Activity的XML主布局中设置一个tool:layout绑定fragment就好了

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".blankStatic">
    <fragment
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:name="com.example.fragment_test.BlankFragment"
        tools:layout="@layout/fragment_blank"
        android:id="@+id/static01"/>
</LinearLayout>


动态创建Fragment(先添加依赖)


动态创建的意思就是在Java代码中加载Fragment


在Activity的主XML文件中创建一个存放Fragment的容器—FragmentContainerView


再在Activity的Java代码中操作绑定Fragment到容器中


1.创建一个Fragment

2.承载Fragment的Activity的XML主布局用容器承接,但不绑定

3.代码中用FragmentManager,FragmentTransaction添加Fragment到容器中(getSupportFragmentManager()方法)

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".blankDsc">
    <androidx.fragment.app.FragmentContainerView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/fra"/>
</LinearLayout>


//只有在AppCompatActivity下或者子类才有此方法getSupportFragmentManager()
FragmentManager supportFragmentManager = getSupportFragmentManager();
//获取一个fragmentTransaction对象
FragmentTransaction fragmentTransaction = supportFragmentManager.beginTransaction();
//把BlankFragment2加载到Activity里面的FragmentContainerView容器中
fragmentTransaction.add(R.id.fra,BlankFragment2.class,null).commit();


静态创建Fragment的时候生命周期函数(Fragment和Avtivity的关系)


Fragment先创建,Activity再创建


Fragment


构造


onInflater——onCreate——onCreateView——onViewCreated——


Activity


onCreate——


Fragment


onActivityCreated——onStart——


Activity


onStart——onResume——


Fragment


onResume。


静态销毁Fragment的时候生命周期函数(Fragment和Avtivity的关系)


Fragment


onPause——


Activity


onPause——


Fragment


onDestroyView——onDestroy——


Activity


onDestroy。


动态创建Fragment的时候生命周期函数(Fragment和Avtivity的关系)


Activity


onCreate


Fragment


构造


onCreate——onCreateView——onViewCreate——onActivityCreate——onStart——


Activity


onStart——onResume——


Fragment


onResume。


动态销毁Fragment的时候生命周期函数(Fragment和Avtivity的关系)

同上静态。


Fragment增删改查


1)增add

//只有在AppCompatActivity下或者子类才有此方法getSupportFragmentManager()
FragmentManager supportFragmentManager = getSupportFragmentManager();
//获取一个fragmentTransaction对象
FragmentTransaction fragmentTransaction = supportFragmentManager.beginTransaction();
//把BlankFragment2加载到Activity里面的FragmentContainerView容器中
fragmentTransaction.add(R.id.fra,BlankFragment2.class,null).commit();

也能addToBackStack到后台栈


2)查find和删remove

//只有在AppCompatActivity下或者子类才有此方法getSupportFragmentManager()
FragmentManager supportFragmentManager = getSupportFragmentManager();
//获取一个fragmentTransaction对象
FragmentTransaction fragmentTransaction = supportFragmentManager.beginTransaction();
//找到容器最上面的Fragment
Fragment frag=supportFragmentManager.findFragmentById(R.id.fra);
if(frag!=null){
    fragmentTransaction.remove(frag).commit();
}


3)换replace

//只有在AppCompatActivity下或者子类才有此方法getSupportFragmentManager()
FragmentManager supportFragmentManager = getSupportFragmentManager();
//获取一个fragmentTransaction对象
FragmentTransaction fragmentTransaction = supportFragmentManager.beginTransaction();
//把BlankFragment2替换到Activity里面的FragmentContainerView容器中
fragmentTransaction.replace(R.id.fra,BlankFragment2.class,null).commit();


4)隐藏hide(相当于View的显示隐藏)

//只有在AppCompatActivity下或者子类才有此方法getSupportFragmentManager()
FragmentManager supportFragmentManager = getSupportFragmentManager();
//获取一个fragmentTransaction对象
FragmentTransaction fragmentTransaction = supportFragmentManager.beginTransaction();
//找到容器最上面的Fragment
Fragment frag=supportFragmentManager.findFragmentById(R.id.fra);
//隐藏
fragmentTransaction.hide(frag).commit();


5)显示show(相当于View的显示隐藏)

//只有在AppCompatActivity下或者子类才有此方法getSupportFragmentManager()
FragmentManager supportFragmentManager = getSupportFragmentManager();
//获取一个fragmentTransaction对象
FragmentTransaction fragmentTransaction = supportFragmentManager.beginTransaction();
//找到容器最上面的Fragment
Fragment frag=supportFragmentManager.findFragmentById(R.id.fra);
//显示
fragmentTransaction.show(frag).commit();


6)隐藏detach


(把Fragment从容器中移除,生命周期执行到onDestroyView,执行onPause和onDestroyView)


(销毁View,不销毁Fragment)(remove都销毁)


同上hide,换个方法名。


7)显示attach


(同上detach),会重新创建View,重新执行好几个创建的生命周期。


同上show,换个方法名。

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