Java android版facebook登录应用程序中的错误

我写了一个faacebook登录android应用程序。
这是我的代码：

MainActivity.java

package edu.cheerz.login;

import java.util.Arrays;

import android.R;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.Menu;
import android.view.MenuItem;

import com.facebook.AppEventsLogger;
import com.facebook.widget.LoginButton;
//import android.support.v7.*;


public class MainActivity extends FragmentActivity {

    private MainFragment mainFragment;
    private static final String TAG = "MainFragment";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (savedInstanceState == null) {
            // Add the fragment on initial activity setup
            mainFragment = new MainFragment();
            getSupportFragmentManager()
            .beginTransaction()
            .add(android.R.id.content, mainFragment)
            .commit();
        } else {
            // Or set the fragment from restored state info
            mainFragment = (MainFragment) getSupportFragmentManager()
            .findFragmentById(android.R.id.content);
        }

        LoginButton authButton = (LoginButton) view.findViewById(R.id.authButton);
        authButton.setFragment(this);
        authButton.setReadPermissions(Arrays.asList("user_likes", "user_status"));
    }

    @Override
    protected void onResume() {
      super.onResume();

      // Logs 'install' and 'app activate' App Events.
      AppEventsLogger.activateApp(this);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_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();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    @Override
    protected void onPause() {
      super.onPause();

      // Logs 'app deactivate' App Event.
      AppEventsLogger.deactivateApp(this);
    }
}

package edu.cheerz.login;

//import android.app.Fragment;
import android.R;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.facebook.Session;
import com.facebook.SessionState;
import com.facebook.UiLifecycleHelper;
import com.facebook.widget.LoginButton;

public class MainFragment extends Fragment {

    private static final String TAG = "MainFragment";
    private UiLifecycleHelper uiHelper;

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

        uiHelper = new UiLifecycleHelper(getActivity(), callback);
        uiHelper.onCreate(savedInstanceState);

        LoginButton authButton = (LoginButton) view.findViewById(R.id.authButton);
        authButton.setFragment(this);
    }

    private void onSessionStateChange(Session session, SessionState state, Exception exception) {
        if (state.isOpened()) {
            Log.i(TAG, "Logged in...");
        } else if (state.isClosed()) {
            Log.i(TAG, "Logged out...");
        }
    }

    private Session.StatusCallback callback = new Session.StatusCallback() {
        @Override
        public void call(Session session, SessionState state, Exception exception) {
            onSessionStateChange(session, state, exception);
        }
    };

    @Override
    public void onResume() {
        super.onResume();
        uiHelper.onResume();
        Session session = Session.getActiveSession();
        if (session != null &&
               (session.isOpened() || session.isClosed()) ) {
            onSessionStateChange(session, session.getState(), null);
        }

        uiHelper.onResume();    
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        uiHelper.onActivityResult(requestCode, resultCode, data);
    }

    @Override
    public void onPause() {
        super.onPause();
        uiHelper.onPause();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        uiHelper.onDestroy();
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        uiHelper.onSaveInstanceState(outState);
    }

}

MainFragment.java

package edu.cheerz.login;

import java.util.Arrays;

import android.R;
import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.view.Menu;
import android.view.MenuItem;

import com.facebook.AppEventsLogger;
import com.facebook.widget.LoginButton;
//import android.support.v7.*;


public class MainActivity extends FragmentActivity {

    private MainFragment mainFragment;
    private static final String TAG = "MainFragment";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        if (savedInstanceState == null) {
            // Add the fragment on initial activity setup
            mainFragment = new MainFragment();
            getSupportFragmentManager()
            .beginTransaction()
            .add(android.R.id.content, mainFragment)
            .commit();
        } else {
            // Or set the fragment from restored state info
            mainFragment = (MainFragment) getSupportFragmentManager()
            .findFragmentById(android.R.id.content);
        }

        LoginButton authButton = (LoginButton) view.findViewById(R.id.authButton);
        authButton.setFragment(this);
        authButton.setReadPermissions(Arrays.asList("user_likes", "user_status"));
    }

    @Override
    protected void onResume() {
      super.onResume();

      // Logs 'install' and 'app activate' App Events.
      AppEventsLogger.activateApp(this);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_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();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    @Override
    protected void onPause() {
      super.onPause();

      // Logs 'app deactivate' App Event.
      AppEventsLogger.deactivateApp(this);
    }
}

package edu.cheerz.login;

//import android.app.Fragment;
import android.R;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.facebook.Session;
import com.facebook.SessionState;
import com.facebook.UiLifecycleHelper;
import com.facebook.widget.LoginButton;

public class MainFragment extends Fragment {

    private static final String TAG = "MainFragment";
    private UiLifecycleHelper uiHelper;

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

        uiHelper = new UiLifecycleHelper(getActivity(), callback);
        uiHelper.onCreate(savedInstanceState);

        LoginButton authButton = (LoginButton) view.findViewById(R.id.authButton);
        authButton.setFragment(this);
    }

    private void onSessionStateChange(Session session, SessionState state, Exception exception) {
        if (state.isOpened()) {
            Log.i(TAG, "Logged in...");
        } else if (state.isClosed()) {
            Log.i(TAG, "Logged out...");
        }
    }

    private Session.StatusCallback callback = new Session.StatusCallback() {
        @Override
        public void call(Session session, SessionState state, Exception exception) {
            onSessionStateChange(session, state, exception);
        }
    };

    @Override
    public void onResume() {
        super.onResume();
        uiHelper.onResume();
        Session session = Session.getActiveSession();
        if (session != null &&
               (session.isOpened() || session.isClosed()) ) {
            onSessionStateChange(session, session.getState(), null);
        }

        uiHelper.onResume();    
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        uiHelper.onActivityResult(requestCode, resultCode, data);
    }

    @Override
    public void onPause() {
        super.onPause();
        uiHelper.onPause();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        uiHelper.onDestroy();
    }

    @Override
    public void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        uiHelper.onSaveInstanceState(outState);
    }

}

但是我遇到了以下错误，我正在尝试修复它。5小时后在这里罢工：）

---

这个错误只是说没有

activity_main.xml

在布局文件夹中

您正在错误行中引用它

错误呢

setFragment（Fragment）不适用于参数（MainActivity）

因为你给了它一个活动作为参数。你可能是说

---

setFragment（mainFragment）

您在活动和片段中使用了相同的布局？这可能不是你想要的。嗯。。。布局文件夹下有

activity\u main.xml

文件。但这里没有提到它。我不知道为什么它会显示相同的错误，除了类型LoginButton中的方法setFragment（Fragment）不适用于参数（MainActivity）MainActivity.java/Login/src/edu/cheerz/Login line 40 java问题