为$安装一个支持库p $ pferenceFragmentCompat [英] Installing a support library for PreferenceFragmentCompat
问题描述
我是新来的Android Studio和在一般的Android编程初学者总额。我看着看着，我无法找到正确的事情。
I'm new to Android Studio and a total beginner at Android programming in general. I looked and looked and I couldn't find the right thing to do.
我要的是安装库使用 preferenceFragmentCompat 或任何替代类的 android.app。preferenceFragment 所以我的应用程序可以在工作11 API和较低的。
All I want is to install a library to use PreferenceFragmentCompat or any class that replaces android.app.PreferenceFragment so my app can work in API 11 and lower.
任何人都可以请给我一些细节，比如哪个库我应该使用以及如何将其安装在我的AS项目。
Can anyone please give me some details such as which library should I use and how to install it in my AS project.
编辑：于是我开始用发展着的这个应用程序 android.support.v4 和 android.support.v7 库来处理的片段，所以我可以在11 API和更低的运行它。
So I started developing this app using android.support.v4 and android.support.v7 libraries to handle the Fragments so I can run it on API 11 and lower.
这是我的 MainActivity.java。
package com.example.myapplication;
import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.app.ActionBar;
import android.content.Context;
import android.os.Build;
import android.os.Bundle;
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;
public class MainActivity extends AppCompatActivity
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_main);
mNavigationDrawerFragment = (NavigationDrawerFragment)
getSupportFragmentManager().findFragmentById(R.id.navigation_drawer);
mTitle = getTitle();
// Set up the drawer.
mNavigationDrawerFragment.setUp(
R.id.navigation_drawer,
(DrawerLayout) findViewById(R.id.drawer_layout));
}
@Override
public void onNavigationDrawerItemSelected(int position) {
Fragment mainFragment = null;
switch(position) {
case 0: // home fragment
mainFragment = new HomeFragment();
break;
case 1: // favorites list
mainFragment = new FaveFragment();
break;
case 2: // rate app
/* visit app TODO put application package id in the link */
Intent visitStore = new Intent(Intent.ACTION_VIEW);
visitStore.setData(Uri.parse("market://details?id=com.google.android.apps.maps"));
startActivity(visitStore);
break;
case 3: // settings
mainFragment = new SettingsFragment();
break;
case 4: // about
mainFragment = new AboutFragment();
break;
}
if(position != 2) {
// update the main content by replacing fragments
FragmentManager fragmentManager = getSupportFragmentManager();
fragmentManager.beginTransaction()
.replace(R.id.container, mainFragment)
.commit();
}
}
public void onSectionAttached(int number) {
String[] stringArray = getResources().getStringArray(R.array.section_titles);
if (number >= 1) {
mTitle = stringArray[number - 1];
}
}
public void restoreActionBar() {
ActionBar actionBar = getSupportActionBar();
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));
}
}
}
现在这是我的 SettingsFragment.java：
package com.example.myapplication;
import android.os.Bundle;
import android.preference.PreferenceFragment;
public class SettingsFragment extends PreferenceFragment {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.settings);
}
}
我在这里遇到的真正问题是这一行： mainFragment =新SettingsFragment（）; 在 onNavigationDrawerItemSelected（INT位置）方法的 MainActivity.java 。
它返回一个错误的说法：
It returns an error saying:
错误：（70 32）错误：不兼容的类型：SettingsFragment不能
转换成片段
Error:(70, 32) error: incompatible types: SettingsFragment cannot be converted to Fragment
我怎样才能解决这个问题，仍然可以使用我的应用程序的API 11和下？
How can I fix this and still be able to use my app on API 11 and lower?
推荐答案
只需更改行
public class SettingsFragment extends PreferenceFragment {
到
public class SettingsFragment extends PreferenceFragmentCompat {
该错误是由 preferenceFragment 引起的，它扩展了 android.app.Fragment ，而不是 android.support.v4.app.Fragment 您需要，只要您使用支持库类。
The error is caused by PreferenceFragment, which extends android.app.Fragment, not android.support.v4.app.Fragment which you need, as you are using support library class.
这篇关于为$安装一个支持库p $ pferenceFragmentCompat的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
