在Android Studio中无法解决getSupportFragmentManager（）方法问题

Question

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我在Android Studio中创建了一个简单的应用程序。我正在使用NavigationDrawerFragment。我插入了日期选择器代码，但在getSupportFragmentManager（）方法中出现错误。

这是我的完整MainActivity代码：

package com.example.clive.mydatepickerapp;

import android.app.Activity;

import android.app.ActionBar;
import android.app.Fragment;
import android.app.FragmentManager;
import android.content.Context;
import android.os.Build;
import android.os.Bundle;
import android.support.v4.app.DialogFragment;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.support.v4.widget.DrawerLayout;
import android.widget.ArrayAdapter;
import android.widget.TextView;
import android.support.v4.app.FragmentActivity;


public class MainActivity extends Activity
        implements NavigationDrawerFragment.NavigationDrawerCallbacks {

    /**
     * Fragment managing the behaviors, interactions and presentation of the navigation drawer.
     */
    private NavigationDrawerFragment mNavigationDrawerFragment;

    /**
     * Used to store the last screen title. For use in {@link #restoreActionBar()}.
     */
    private CharSequence mTitle;

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



        mNavigationDrawerFragment = (NavigationDrawerFragment)
                getFragmentManager().findFragmentById(R.id.navigation_drawer);
        mTitle = getTitle();

        // Set up the drawer.
        mNavigationDrawerFragment.setUp(
                R.id.navigation_drawer,
                (DrawerLayout) findViewById(R.id.drawer_layout));
    }

    public void doDatePicker(View view) {
        DialogFragment myDatePickerFragment = new MyDatePickerFragment();
        myDatePickerFragment.show(getSupportFragmentManager(), "datePicker");
    }

    @Override
    public void onNavigationDrawerItemSelected(int position) {
        // update the main content by replacing fragments
        FragmentManager fragmentManager = getFragmentManager();
        fragmentManager.beginTransaction()
                .replace(R.id.container, PlaceholderFragment.newInstance(position + 1))
                .commit();
    }

    public void onSectionAttached(int number) {
        switch (number) {
            case 1:
                mTitle = getString(R.string.title_section1);
                break;
            case 2:
                mTitle = getString(R.string.title_section2);
                break;
            case 3:
                mTitle = getString(R.string.title_section3);
                break;
        }
    }

    public void restoreActionBar() {
        ActionBar actionBar = getActionBar();
        actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
        actionBar.setDisplayShowTitleEnabled(true);
        actionBar.setTitle(mTitle);
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        if (!mNavigationDrawerFragment.isDrawerOpen()) {
            // Only show items in the action bar relevant to this screen
            // if the drawer is not showing. Otherwise, let the drawer
            // decide what to show in the action bar.
            getMenuInflater().inflate(R.menu.main, menu);
            restoreActionBar();
            return true;
        }
        return super.onCreateOptionsMenu(menu);
    }

    @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);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {
        /**
         * The fragment argument representing the section number for this
         * fragment.
         */
        private static final String ARG_SECTION_NUMBER = "section_number";

        /**
         * Returns a new instance of this fragment for the given section
         * number.
         */
        public static PlaceholderFragment newInstance(int sectionNumber) {
            PlaceholderFragment fragment = new PlaceholderFragment();
            Bundle args = new Bundle();
            args.putInt(ARG_SECTION_NUMBER, sectionNumber);
            fragment.setArguments(args);
            return fragment;
        }

        public PlaceholderFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                                 Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container, false);
            return rootView;
        }

        @Override
        public void onAttach(Activity activity) {
            super.onAttach(activity);
            ((MainActivity) activity).onSectionAttached(
                    getArguments().getInt(ARG_SECTION_NUMBER));
        }
    }

}

请帮忙！！

- appu

---

这个活动是从片段活动扩展的吗？ - Durga Mohan

你是在Fragment还是Activity中使用这段代码？ - Hasmukh Barochiya

让你的MainActivity扩展FragmentActivity并导入android.support.v4.app.Fragment。 - Bidhan

Answer 1

替换 Activity：

public class MainActivity extends Activity

扩展 FragmentActivity：

public class MainActivity extends FragmentActivity

确保您正在导入 SupportLibrary：

import android.support.v4.app.Fragment;

为了使用getSupportFragmentManager()，您需要：

- hrskrs

Answer 2

我曾经遇到同样的问题。后来我用getFragmentManager()代替了getSupportFragmentManager()，问题得到了解决！

我使用了以下两个导入:

import android.support.v4.app.Fragment;
import android.app.FragmentTransaction;

我的MainActivity扩展了Activity类。

- Anshul Gupta

---

太棒了兄弟！在大多数情况下，这是正确的解决方案。 - dharam

Answer 3

我遇到了这些问题很多次。对我有用的是：

简单地将主类扩展为AppCompatActivity而不是通常的ACTIVITY。

简而言之：

用AppCompatActivity替换Acivity。

- 1ambharath

Answer 4

与其使用public class MainActivity extends Activity，

不如使用public class MainActivity extends AppCompatActivity，它支持片段管理器。

- nimi0112

Answer 5

只有在使用支持片段类的情况下，这才有效，即你必须

import android.support.v4.app.Fragment;

- Paritosh

---

你能添加你的导入和类声明吗？ - Paritosh