我创建了两个片段:'schedule fragment'和'clock 设置后
public class ClockFragment extends AppCompatActivity implements View.OnClickListener {
private int notificationId = 1;
在Mainactivity.java中，pageAdapter
scheduleFragment = new ScheduleFragment();
clockFragment = new ClockFragment();
tabLayout.setupWithViewPager(viewPager);
ViewPagerAdapter viewPagerAdapter = new ViewPagerAdapter(getSupportFragmentManager(), 0);
viewPagerAdapter.addFragment(clockFragment, "Clock");
viewPagerAdapter.addFragment(scheduleFragment, "Schedule");
viewPager.setAdapter(viewPagerAdapter);
创建一个错误，声明我必须将clockFragment转换为scheduleFragment，以便创建一个片段。
我需要这两个片段，因为在ClockFragment（tab）中，时钟必须显示给用户，而在ScheduleFragment（tab）中，则显示用户的日程安排。 我不确定如何才能在不导致错误的情况下将两个选项卡分开。
如果您能解释一下为什么会出现这个错误，并给出解决方案，我们将非常感激。
首先，ClockFragment扩展了activity，这意味着它不是一个片段。
我给你举一个例子，说明你应该如何做事:
public class ChildFragment1 extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View rootView = inflater.inflate(R.layout.child_fragment_1_layout, container, false);
Button buttonInFragment1 = rootView.findViewById(R.id.button_1);
buttonInFragment1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Toast.makeText(getContext(), "button in fragment 1", Toast.LENGTH_SHORT).show();
}
});
return rootView;
}
}
现在执行片段2:
public class ChildFragment2 extends Fragment {
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View rootView = inflater.inflate(R.layout.child_fragment_1_layout, container, false);
Button buttonInFragment1 = rootView.findViewById(R.id.button_1);
buttonInFragment1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Toast.makeText(getContext(), "button in fragment 2", Toast.LENGTH_SHORT).show();
}
});
return rootView;
}
}
现在为适配器添加一个新类:
public class ViewPagerAdapter extends FragmentPagerAdapter {
public ViewPagerAdapter(FragmentManager fm) {
super(fm);
}
@Override
public Fragment getItem(int position) {
switch (position)
{
case 0:
return new ChildFragment1(); //ChildFragment1 at position 0
case 1:
return new ChildFragment2(); //ChildFragment2 at position 1
}
return null; //does not happen
}
@Override
public int getCount() {
return 2; //three fragments
}
}
你的主要活动应该是这样的:
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewPager viewPager = findViewById(R.id.view_pager);
viewPager.setAdapter(new ViewPagerAdapter(getSupportFragmentManager()));
}
}
