Question

我想在Fragment中使用ImageButton播放mp3。这是我的代码：公共类FirstFragment扩展Fragment {

View myView;
MediaPlayer mp;

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    myView = inflater.inflate(R.layout.first_layout, container, false);
    return myView;

    ImageButton btn  = (ImageButton)getView().findViewById(R.id.paratha);

    //on click button for paratha
    btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            MediaPlayer paratha = MediaPlayer.create(this, R.raw.paratha);

            paratha.start();
        }
    });
}

}

Answer 1

您将click侦听器设置在return语句下方。这是错误的，getActivity()中的上下文应该是this而不是MediaPlayer，因为您使用的是fragment而不是activity。像这样改变你的方法：

    View myView;
    MediaPlayer mp;

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        myView = inflater.inflate(R.layout.first_layout, container, false);

        ImageButton btn  = (ImageButton)myView.findViewById(R.id.paratha);

        //on click button for paratha
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                MediaPlayer paratha = MediaPlayer.create(getActivity(), R.raw.paratha);

                paratha.start();
            }
        });

        return myView;
    }

希望有所帮助！

Answer 2

我想在媒体播放器完成音频后移动下一个屏幕。

公共类FirstFragment扩展了Fragment {

View myView;
MediaPlayer mp;
ImageButton btn;

@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    myView = inflater.inflate(R.layout.first_layout, container, false);

    btn = (ImageButton) myView.findViewById(R.id.paratha);

    //on click button for paratha
    btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            MediaPlayer paratha = MediaPlayer.create(getActivity(), R.raw.paratha);
            paratha.start();

            paratha.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
                @Override
                public void onCompletion(MediaPlayer mp) {
                    nextscreen();
                }
            });
        }
    });
    return myView;
}

public void  nextscreen() {
    Intent intent = new Intent(getActivity(), SecondFragment.class);
    getActivity().startActivity(intent);

}

}

MainActivity文件位于：

公共类MainActivity扩展了AppCompatActivity 实现NavigationView.OnNavigationItemSelectedListener {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
                    .setAction("Action", null).show();
        }
    });

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.setDrawerListener(toggle);
    toggle.syncState();

    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);
}

@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    } else {
        super.onBackPressed();
    }
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.
    int id = item.getItemId();
    FragmentManager fragmentManager = getFragmentManager();

    if (id == R.id.nav_first_layout) {
        fragmentManager.beginTransaction()
                .replace(R.id.content_frame
                        , new FirstFragment())
                .commit();
                        // Handle the camera action
    } else if (id == R.id.nav_second_layout) {

    } else if (id == R.id.nav_slideshow) {

    } else if (id == R.id.nav_manage) {

    } else if (id == R.id.nav_share) {

    } else if (id == R.id.nav_send) {

    }

    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.closeDrawer(GravityCompat.START);
    return true;
}

}

second_layout xml文件：公共类SecondFragment扩展Fragment {

View secView;

@Nullable
@Override

public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    secView = inflater.inflate(R.layout.second_layout, container, false);
    return secView;
}

}

Answer 3

您的nextscreen()方法应如下：

public void  nextscreen() {
        SecondFragment fragment = new SecondFragment();
        FragmentManager fragmentManager = getActivity().getFragmentManager();
        FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
        fragmentTransaction.replace(R.id.content_frame, fragment);
        fragmentTransaction.addToBackStack(null);
        fragmentTransaction.commit();
}

您想要制作意图，但需要事务来加载第二个片段。

想要在片段

3 个答案: