Android - Fragment 碎片

Android - Fragment 碎片

Fragment需要嵌套在Activity中使用,也可以嵌套在另个Fragment中

第一步	设计主界面，留出用到碎片的部分
第二步	设计碎片布局，编写Java代码继承Fragment，重写onCreateView
第三步	编写点击事件，呈现相应的碎片

主布局

<?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="vertical">


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">


        <LinearLayout
            android:id="@+id/linearlayout1"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="9"
            android:orientation="vertical">
        </LinearLayout>
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:orientation="horizontal">

            <Button
                android:id="@+id/button1"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:text="消息"
                android:textSize="20sp"
                android:background="@android:color/transparent"/>

            <Button
                android:id="@+id/button2"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:text="联系人"
                android:textSize="20sp"
                android:background="@android:color/transparent"/>

            <Button
                android:id="@+id/button3"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:text="空间"
                android:textSize="20sp"
                android:background="@android:color/transparent"/>

            <Button
                android:id="@+id/button4"
                android:layout_width="wrap_content"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:text="我"
                android:textSize="20sp"
                android:background="@android:color/transparent"/>
        </LinearLayout>
    </LinearLayout>

</LinearLayout>

碎片布局

<?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:gravity="center">

    <TextView
        android:id="@+id/textView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="消息 碎片"
        android:textSize="50dp"
        android:gravity="center"/>
</LinearLayout>

编写碎片Java代码

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

主代码

public class MainActivity extends AppCompatActivity {
    
    

    Button button1;
    LinearLayout linearLayout1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    
    
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
		button1 = findViewById(R.id.button1);
        linearLayout1 = findViewById(R.id.linearlayout1);
        
        button1.setOnClickListener(new View.OnClickListener() {
    
    
            @Override
            public void onClick(View view) {
    
    
                getSupportFragmentManager().beginTransaction().replace(R.id.linearlayout1,new fragment()).commit();
            }
        });
    }
}

运行后为空，点击消息显示
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