Android片段类型不匹配

Question

我是android新手，正在关注Dartmouth的教程。 http://www.cs.dartmouth.edu/~campbell/cs65/lecture08/lecture08.html

我正在遵循所有代码，并在MainActivity.java中，

// create the fragments
Fragment mFindFragment = new FindFragment();
Fragment mChatFragment = new ChatFragment();

// bind the fragments to the tabs - set up tabListeners for each tab 
mFindTab.setTabListener(new MyTabsListener(mFindFragment,
                           getApplicationContext()));
mChatTab.setTabListener(new MyTabsListener(mChatFragment,
                           getApplicationContext()));

我遇到此错误：类型不匹配：无法从FindFragment转换为Fragment。 所以我遵循修复错误建议，并将代码更改为

// create the fragments
FindFragment mFindFragment = new FindFragment();

// bind the fragments to the tabs - set up tabListeners for each tab 
mFindTab.setTabListener(new MyTabsListener(mFindFragment,
                           getApplicationContext()));

现在，出现一个新错误：构造函数MyTabsListener（FindFragment，Context）未定义。

以防万一进口很关键，这里是：

import android.app.ActionBar;
import android.app.ActionBar.Tab;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.content.Context;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.Toast;

对于myTabsListener：

  class MyTabsListener implements ActionBar.TabListener {
    public Fragment fragment;
    public Context context;

    public MyTabsListener(Fragment fragment, Context context) {
        this.fragment = fragment;
        this.context = context;

    }

    @Override
    public void onTabReselected(Tab tab, FragmentTransaction ft) {
        Toast.makeText(context, "Reselected!", Toast.LENGTH_SHORT).show();

    }

    @Override
    public void onTabSelected(Tab tab, FragmentTransaction ft) {
        Toast.makeText(context, "Selected!", Toast.LENGTH_SHORT).show();
        ft.replace(R.id.container, fragment);
    }

    @Override
    public void onTabUnselected(Tab tab, FragmentTransaction ft) {
        Toast.makeText(context, "Unselected!", Toast.LENGTH_SHORT).show();
        ft.remove(fragment);
    }

}

对于我的FindFragment类：

import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class FindFragment extends Fragment {
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.findfragment, container, false);
    }


}

我在这里很困惑。 我不确定这是否与我的导入，库设置或其他问题有关。 提前致谢！

Answer 1

你需要改变这个

import android.support.v4.app.Fragment;
// you will use this import when you want fragment from support library 
// in that case you will extend FragmentActivity which is the base class for support based fragments

至

import android.app.Fragment;

在FindFragment.java 。

同样在ChatFragment.java也做同样的ChatFragment.java