android编程4.2.2

alltolove

我们既要碎片化学习也要碎片化编程，碎片化编程手机软件是今年来非常流行的，比如制作页签换页效果等。今天的动态添加碎片是以后比较常用的方法。我们继续昨天的项目，先在layout目录下新建another_right_fragment.xml文件：

<?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">
<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/another"
    android:textSize="20sp"
    android:layout_gravity="center_horizontal"
    android:text="This is another fragment"/>
</LinearLayout>

然后把这个布局文件制作成碎片，在mainactivity.java旁边新建一个AnotherRightFragment.java类

package com.example.xinwei.fragmentactivity;

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;

/**
 * Created by xinwei on 2017/10/3.
 */

public class AnotherRightFragment extends Fragment {
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.another_right_fragment,container,false);
        return view;
    }
}

然后，换一个可以被替换的控件，修改activity_main.xml文件：

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

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

    <FrameLayout
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:id="@+id/right_layout"
        android:layout_weight="1" />
</LinearLayout>

修改mainactivity.java

package com.example.xinwei.fragmentactivity;

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);
        replaceFragment(new RightFragment());
    }

    private void replaceFragment(Fragment fragment) {
        FragmentManager fragmentManager=getSupportFragmentManager();
        FragmentTransaction transition=fragmentManager.beginTransaction();
        transition.replace(R.id.right_layout,fragment);
        transition.commit();
    }

    @Override
    public void onClick(View view) {
        replaceFragment(new AnotherRightFragment());
    }



}

效果图：