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  • Android动态添加碎片

    我们编写一个能够用过按钮动态更替碎片的APP,首先在主页上显示第一个碎片,点击按钮后可以替换到第二个碎片,或者删除已经替换掉的第二个碎片。

    一.MainActivity.java

    import androidx.fragment.app.FragmentActivity;
    import androidx.fragment.app.FragmentManager;
    import androidx.fragment.app.FragmentTransaction;
    
    import android.os.Bundle;
    import android.util.Log;
    import android.view.View;
    import android.widget.Button;
    
    public class MainActivity extends FragmentActivity {
    
        public MainActivity() {
            Log.e("TAG", "MainActivity()..");
        }
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            Log.e("TAG", "MainActivity onCreate()..");
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);//重写onCreate()方法
    
    
            // 创建Fragment对象
            final MyFragment1 fragment1 = new MyFragment1();
            // 得到FragmentManager
            FragmentManager manager = getSupportFragmentManager();
            // 得到FragmentTransacation
            FragmentTransaction transaction = manager.beginTransaction();
            // 添加Fragment对象并提交
            transaction.add(R.id.ll_main, fragment1).commit();
    
            Button button1=(Button)findViewById(R.id.fragment_1);
            button1.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    showFragment2();
                }
            });
            Button button2=(Button)findViewById(R.id.fragment_2);
            button2.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    deleteFragment2();
                }
            });
    
        }
        private MyFragment2 fragment2;
        public void showFragment2() {
            // 创建Fragment对象
            fragment2 = new MyFragment2();
            // 得到FragmentManager
            FragmentManager manager = getSupportFragmentManager();
            // 得到FragmentTransacation
            FragmentTransaction transaction = manager.beginTransaction();
    
            //将当前操作添加到回退栈, 这样点击back回到上一个状态
            transaction.addToBackStack(null);
    
            // 替换Fragment对象并提交
            transaction.replace(R.id.ll_main, fragment2).commit();
        }
        public void deleteFragment2() {
    
            // 得到FragmentManager
            FragmentManager manager = getSupportFragmentManager();
            // 得到FragmentTransacation
            FragmentTransaction transaction = manager.beginTransaction();
            // 移除Fragment对象并提交
            transaction.remove(fragment2).commit();
        }
    }

    二.activity_main.xml

    <?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=".MainActivity">
        <LinearLayout
            android:orientation="horizontal"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">
    <Button
    
        android:id="@+id/fragment_1"
        android:text="切换至第二个碎片"
        android:layout_width="0dp"
        android:layout_weight="1"
        android:layout_height="wrap_content" />
        <Button
            android:id="@+id/fragment_2"
            android:text="删除第二个碎片"
            android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_height="wrap_content" />
        </LinearLayout>
    <LinearLayout
        android:id="@+id/ll_main"
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    
    
    </LinearLayout>
    </LinearLayout>

    编写好的界面如下图所示:

    三.MyFragment1.java

    import android.os.Bundle;
    
    import androidx.fragment.app.Fragment;
    
    import android.util.Log;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.TextView;
    
    
    public class MyFragment1 extends Fragment {
    
    
    
        public MyFragment1() {
            // Required empty public constructor
        }
    
    
    
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
    
        }
    
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            // Inflate the layout for this fragment
            return inflater.inflate(R.layout.fragment_my_fragment1, container,false);
        }
    
    
    }

    四.MyFragment2.java

    import android.os.Bundle;
    
    import androidx.fragment.app.Fragment;
    
    import android.util.Log;
    import android.view.LayoutInflater;
    import android.view.View;
    import android.view.ViewGroup;
    import android.widget.TextView;
    
    
    
    public class MyFragment2 extends Fragment {
        public MyFragment2() {
            // Required empty public constructor
        }
    
    
    
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
    
        }
    
        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            // Inflate the layout for this fragment
            return inflater.inflate(R.layout.fragment_my_fragment2, container,false);
        }
    
    }

    五.fragment1.xml

    <?xml version="1.0" encoding="utf-8"?>
    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MyFragment1">
    
        <!-- TODO: Update blank fragment layout -->
        <TextView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:text="这是第一个碎片" />
    
    </FrameLayout>

    六.fragment2.xml

    <?xml version="1.0" encoding="utf-8"?>
    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MyFragment2">
    
        <!-- TODO: Update blank fragment layout -->
        <TextView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:text="这是第二个碎片" />
    
    </FrameLayout>

    完毕

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  • 原文地址:https://www.cnblogs.com/geeksongs/p/11979054.html
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