009 Android Fragment动态用法（实现动态菜单栏）设置控件为满屏状态

·1.MainActivity采用线性布局

2.在app--->res--->layout,右击new--->xml---->layout xml FILE

<1>新建XML文件

采用线性布局

<?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:background="#fffff0"
    android:layout_height="match_parent">

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:text="隐藏" />
</LinearLayout>

3.在app-->java--->com.lucky.test07目录下新建MyFragment类

View.inflate()是加载一个布局文件

View view=inflater.inflate(R.layout.layout1,container,false);

package com.lucky.test07;

import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.LinearLayout;

public class MyFragment extends Fragment {
    LinearLayout linearLayout;
    Button button2;
    FragmentManager fragmentManager;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view=inflater.inflate(R.layout.layout1,container,false);
        linearLayout=getActivity().findViewById(R.id.line1); //通过getActivity()获取activity_main.xml文件中id号为line1的LinearLayout布局
        button2=view.findViewById(R.id.button2);
        button2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                fragmentManager=getFragmentManager(); //实例化fragmentManager
                FragmentTransaction transaction=fragmentManager.beginTransaction(); //用来提交数据
                transaction.remove(MyFragment.this); //移除MyFragment
                transaction.commit(); //提交数据
                maxScreen();  //调用满屏函数

            }
        });

        return view;
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        maxScreen();
    }

    //设置线性布局为满屏
    public void maxScreen(){
        linearLayout.setLayoutParams(new LinearLayout.LayoutParams(getActivity().getWindowManager().getDefaultDisplay().getWidth(),
                getActivity().getWindowManager().getDefaultDisplay().getHeight()));
    }
}

4.在MainActivity.java中应用Fragment

public class MainActivity extends AppCompatActivity {
    Button button;  //定义一个按钮，将其引入后台
    FragmentManager fragmentManager;//定义一个fragmentManager
    LinearLayout linearLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        button=findViewById(R.id.button);
        linearLayout=findViewById(R.id.line1);  //实例化linearLayout
        fragmentManager=getSupportFragmentManager(); //初始化fragmentManager

        //绑定点击事件
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //设置线性布局的宽度
                linearLayout.setLayoutParams(new LinearLayout.LayoutParams(getWindowManager().getDefaultDisplay().getWidth()/3,
                        getWindowManager().getDefaultDisplay().getHeight()));
                FragmentTransaction transaction=fragmentManager.beginTransaction();  //用来提交数据
                transaction.replace(R.id.layout_main,new MyFragment()); //添加数据，参数1为activity_main.xml文件中的id
                transaction.addToBackStack(null); //监听退出键，若按退出键会返回上一级应用
                transaction.commit(); //提交数据
            }
        });
    }
}

效果图：