Android 向 Activity 添加片段

管理片段

FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();


Java
public class MainActivity extends AppCompatActivity {
    private Integer con = 0;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        FragmentManager fragmentManager = getFragmentManager();
        FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
        // 方法1
        // Frag1 f1 = (Frag1) fragmentManager.findFragmentById(R.id.fragment);
        // 方法2
        Frag1 f1 = (Frag1) fragmentManager.findFragmentByTag("tag");
        Button bt = (Button) f1.getView().findViewById(R.id.button);
        bt.setText("Fragmentbut");
        bt.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                con = con + 1;
                Toast.makeText(MainActivity.this, "Count" + con, Toast.LENGTH_SHORT).show();
            }
        });
    }
}


<?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:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.e560.m1014c.MainActivity">


    <fragment
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:name="com.example.e560.m1014c.Frag1"
        android:tag="tag"
        android:layout_weight="1" />
</LinearLayout>