Android 安卓新意图与碎片
我正在开发使用fragment的Android应用程序。单击左上角的菜单图标时，将显示菜单列表。单击一个菜单项后，它创建一个新的意图并启动一个新的活动，该活动也使用相同菜单顺序的片段。问题是，当新活动启动时，它将立即调用第一个菜单项的意图。我不想更改每个活动的顺序，但我希望应用程序仅在用户单击菜单项时切换到其他活动。如何制作这样的程序 例如，如果这是Activity1的onSectionAttached方法。当Activity1启动时，它将立即切换到MainActivity。如果用户单击菜单，如何使应用程序仅切换到MainActivity Bakteri.javaAndroid 安卓新意图与碎片,android,android-fragments,android-intent,Android,Android Fragments,Android Intent,我正在开发使用fragment的Android应用程序。单击左上角的菜单图标时，将显示菜单列表。单击一个菜单项后，它创建一个新的意图并启动一个新的活动，该活动也使用相同菜单顺序的片段。问题是，当新活动启动时，它将立即调用第一个菜单项的意图。我不想更改每个活动的顺序，但我希望应用程序仅在用户单击菜单项时切换到其他活动。如何制作这样的程序 例如，如果这是Activity1的onSectionAttached方法。当Activity1启动时，它将立即切换到MainActivity。如果用户单击菜单，如
package com.example.app02;
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.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.text.Editable;
import android.text.TextWatcher;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
import android.content.Intent;
import android.database.Cursor;
import android.database.SQLException;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
public class Bakteri extends Activity implements
NavigationDrawerFragment.NavigationDrawerCallbacks {
static DBHelper dbhelper;
static Cursor c=null;
static ListView list;
/**
* 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) getFragmentManager()
.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) {
// update the main content by replacing fragments
FragmentManager fragmentManager = getFragmentManager();
fragmentManager
.beginTransaction()
.replace(R.id.container,
PlaceholderFragment.newInstance(position + 1)).commit();
Intent intent;
switch(position){
case 0:
//To start a new activity
intent = new Intent(this,MainActivity.class);
startActivity(intent);
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();
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;
}
protected Context context;
public PlaceholderFragment() {
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container,
false);
//access database
dbhelper = new DBHelper(getActivity());
try {
dbhelper.createDataBase();
} catch (IOException ioe) {
throw new Error("Unable to create database");
}
try {
dbhelper.openDataBase();
}catch(SQLException sqle){
throw sqle;
}
final TextView txvMain = (TextView) rootView.findViewById(R.id.result);
txvMain.setText("Bakteri");
list = (ListView) rootView.findViewById(R.id.list);
final EditText search = (EditText) rootView.findViewById(R.id.search);
search.addTextChangedListener(new TextWatcher(){
public void onTextChanged(CharSequence s, int start, int before, int count){
ArrayList<String> list_title = new ArrayList();
ArrayList<String> list_content = new ArrayList();
if(!s.equals("")){
c=dbhelper.query("bakteri", null, "nama_ilmiah LIKE '%" + search.getText() + "%'", null, null,null, null);
String res = "";
if(c.moveToFirst())
{
do {
list_title.add(c.getString(0));
list_content.add(c.getString(1));
res += c.getString(0) + "\n" + c.getString(1) + "\n" + "\n";
} while (c.moveToNext());
}
String[] title = new String[ list_title.size() ];
list_title.toArray(title);
String[] content = new String[ list_content.size() ];
list_content.toArray(content);
CustomList adapter = new CustomList(getActivity(), title, content);
list.setAdapter(adapter);
//txvMain.setText(res);
}
}
public void beforeTextChanged(CharSequence s, int start, int count, int after){
}
public void afterTextChanged(Editable s){
}
});
//set a drawable as the background of the textView
return rootView;
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
}
}
@Override
protected void onDestroy() {
super.onDestroy();
if (dbhelper != null) {
dbhelper.close();
}
}
}
package com.example.app02；
导入android.app.Activity；
导入android.app.ActionBar；
导入android.app.Fragment；
导入android.app.FragmentManager；
导入android.content.Context；
导入android.os.Build；
导入android.os.Bundle；
导入android.view.Gravity；
导入android.view.LayoutInflater；
导入android.view.Menu；
导入android.view.MenuItem；
导入android.view.view；
导入android.view.ViewGroup；
导入android.support.v4.widget.DrawerLayout；
导入android.text.Editable；
导入android.text.TextWatcher；
导入android.widget.ArrayAdapter；
导入android.widget.EditText；
导入android.widget.ListView；
导入android.widget.TextView；
导入android.widget.Toast；
导入android.content.Intent；
导入android.database.Cursor；
导入android.database.SQLException；
导入java.io.IOException；
导入java.util.ArrayList；
导入java.util.List；
公共类Bakteri扩展了活动实现
NavigationDrawerFragment.NavigationDrawerCallbacks{
静态DBHelper-DBHelper；
静态游标c=null；
静态列表视图列表；
/**
*片段管理项目的行为、交互和表示
*导航抽屉。
*/
私人导航抽屉碎片mnavigation抽屉碎片；
/**
*用于存储最后一个屏幕标题。用于
*{@link#restoreActionBar（）}。
*/
私有字符序列mTitle；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_main）；
mNavigationDrawerFragment=（NavigationDrawerFragment）getFragmentManager（）
.findFragmentById（R.id.navigation\U抽屉）；
mTitle=getTitle（）；
//把抽屉摆好。
mNavigationDrawerFragment.setUp（R.id.navigation\u drawer，
（抽屉布局）findViewById（R.id.抽屉布局）；
}
@凌驾
已选择NavigationDrawerItems上的公共无效（整数位置）{
//通过替换片段更新主要内容
FragmentManager FragmentManager=getFragmentManager（）；
碎片管理器
.beginTransaction（）
.更换（R.id.容器，
占位符片段.newInstance（位置+1））.commit（）；
意图；
开关（位置）{
案例0：
//开始一项新的活动
意图=新意图（此，MainActivity.class）；
星触觉（意向）；
打破
}
}
public void restoreActionBar（）{
ActionBar ActionBar=getActionBar（）；
actionBar.setNavigationMode（actionBar.NAVIGATION_模式_标准）；
actionBar.setDisplayShowTitleEnabled（true）；
actionBar.setTitle（mTitle）；
}
@凌驾
公共布尔onCreateOptions菜单（菜单）{
如果（！mNavigationDrawerFragment.isDrawerOpen（））{
//仅在操作栏中显示与此屏幕相关的项目
//如果抽屉没有显示。否则，让抽屉显示
//决定在动作栏中显示什么。
getMenuInflater（）.充气（R.menu.main，menu）；
restoreActionBar（）；
返回true；
}
返回super.onCreateOptions菜单（菜单）；
}
@凌驾
公共布尔值onOptionsItemSelected（菜单项项）{
//处理操作栏项目单击此处。操作栏将
//自动处理Home/Up按钮上的点击，只要
//在AndroidManifest.xml中指定父活动时。
int id=item.getItemId（）；
if（id==R.id.action\u设置）{
返回true；
}
返回super.onOptionsItemSelected（项目）；
}
/**
*包含简单视图的占位符片段。
*/
公共静态类占位符片段扩展了片段{
/**
*表示此文件节号的片段参数
*碎片。
*/
私有静态最终字符串ARG\u SECTION\u NUMBER=“SECTION\u NUMBER”；
/**
*返回给定节号的此片段的新实例。
*/
公共静态占位符片段newInstance（int sectionNumber）{
占位符片段=新占位符片段（）；
Bundle args=新Bundle（）；
参数Putin（参数段号，段号）；
fragment.setArguments（args）；
返回片段；
}
受保护的语境；
公共占位符片段（）{
}
@凌驾
创建视图上的公共视图（布局、充气机、视图组容器、，
Bundle savedInstanceState）{
视图根视图=充气机。充气（R.layout.fragment_main，容器，
假）；
//access数据库
dbhelper=新的dbhelper（getActivity（））；
试一试{
dbhelper.createDataBase（）；
}捕获（ioe异常ioe）{
抛出新错误（“无法创建数据库”）；
}
试一试{
dbhelper.openDataBase（）；
}捕获（SQLException sqle）{
抛出sqle；
}
package com.example.app02;
import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.content.SharedPreferences;
import android.content.res.Configuration;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
/**
* Fragment used for managing interactions for and presentation of a navigation
* drawer. See the <a href=
* "https://developer.android.com/design/patterns/navigation-drawer.html#Interaction"
* > design guidelines</a> for a complete explanation of the behaviors
* implemented here.
*/
public class NavigationDrawerFragment extends Fragment {
/**
* Remember the position of the selected item.
*/
private static final String STATE_SELECTED_POSITION = "selected_navigation_drawer_position";
/**
* Per the design guidelines, you should show the drawer on launch until the
* user manually expands it. This shared preference tracks this.
*/
private static final String PREF_USER_LEARNED_DRAWER = "navigation_drawer_learned";
/**
* A pointer to the current callbacks instance (the Activity).
*/
private NavigationDrawerCallbacks mCallbacks;
/**
* Helper component that ties the action bar to the navigation drawer.
*/
private ActionBarDrawerToggle mDrawerToggle;
private DrawerLayout mDrawerLayout;
private ListView mDrawerListView;
private View mFragmentContainerView;
private int mCurrentSelectedPosition = 0;
private boolean mFromSavedInstanceState;
private boolean mUserLearnedDrawer;
public NavigationDrawerFragment() {
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Read in the flag indicating whether or not the user has demonstrated
// awareness of the
// drawer. See PREF_USER_LEARNED_DRAWER for details.
SharedPreferences sp = PreferenceManager
.getDefaultSharedPreferences(getActivity());
mUserLearnedDrawer = sp.getBoolean(PREF_USER_LEARNED_DRAWER, false);
if (savedInstanceState != null) {
mCurrentSelectedPosition = savedInstanceState
.getInt(STATE_SELECTED_POSITION);
mFromSavedInstanceState = true;
}
// Select either the default item (0) or the last selected item.
selectItem(mCurrentSelectedPosition);
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
// Indicate that this fragment would like to influence the set of
// actions in the action bar.
setHasOptionsMenu(true);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
mDrawerListView = (ListView) inflater.inflate(
R.layout.fragment_navigation_drawer, container, false);
mDrawerListView
.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
selectItem(position);
}
});
mDrawerListView.setAdapter(new ArrayAdapter<String>(getActionBar()
.getThemedContext(),
android.R.layout.simple_list_item_activated_1,
android.R.id.text1, new String[] {
getString(R.string.title_home),
getString(R.string.title_section1),
getString(R.string.title_section2),
getString(R.string.title_section3),
getString(R.string.title_section4),
getString(R.string.title_section5)}));
mDrawerListView.setItemChecked(mCurrentSelectedPosition, true);
return mDrawerListView;
}
public boolean isDrawerOpen() {
return mDrawerLayout != null
&& mDrawerLayout.isDrawerOpen(mFragmentContainerView);
}
/**
* Users of this fragment must call this method to set up the navigation
* drawer interactions.
*
* @param fragmentId
* The android:id of this fragment in its activity's layout.
* @param drawerLayout
* The DrawerLayout containing this fragment's UI.
*/
public void setUp(int fragmentId, DrawerLayout drawerLayout) {
mFragmentContainerView = getActivity().findViewById(fragmentId);
mDrawerLayout = drawerLayout;
// set a custom shadow that overlays the main content when the drawer
// opens
mDrawerLayout.setDrawerShadow(R.drawable.drawer_shadow,
GravityCompat.START);
// set up the drawer's list view with items and click listener
ActionBar actionBar = getActionBar();
actionBar.setDisplayHomeAsUpEnabled(true);
actionBar.setHomeButtonEnabled(true);
// ActionBarDrawerToggle ties together the the proper interactions
// between the navigation drawer and the action bar app icon.
mDrawerToggle = new ActionBarDrawerToggle(getActivity(), /* host Activity */
mDrawerLayout, /* DrawerLayout object */
R.drawable.ic_drawer, /* nav drawer image to replace 'Up' caret */
R.string.navigation_drawer_open, /*
* "open drawer" description for
* accessibility
*/
R.string.navigation_drawer_close /*
* "close drawer" description for
* accessibility
*/
) {
@Override
public void onDrawerClosed(View drawerView) {
super.onDrawerClosed(drawerView);
if (!isAdded()) {
return;
}
getActivity().invalidateOptionsMenu(); // calls
// onPrepareOptionsMenu()
}
@Override
public void onDrawerOpened(View drawerView) {
super.onDrawerOpened(drawerView);
if (!isAdded()) {
return;
}
if (!mUserLearnedDrawer) {
// The user manually opened the drawer; store this flag to
// prevent auto-showing
// the navigation drawer automatically in the future.
mUserLearnedDrawer = true;
SharedPreferences sp = PreferenceManager
.getDefaultSharedPreferences(getActivity());
sp.edit().putBoolean(PREF_USER_LEARNED_DRAWER, true)
.apply();
}
getActivity().invalidateOptionsMenu(); // calls
// onPrepareOptionsMenu()
}
};
// If the user hasn't 'learned' about the drawer, open it to introduce
// them to the drawer,
// per the navigation drawer design guidelines.
if (!mUserLearnedDrawer && !mFromSavedInstanceState) {
mDrawerLayout.openDrawer(mFragmentContainerView);
}
// Defer code dependent on restoration of previous instance state.
mDrawerLayout.post(new Runnable() {
@Override
public void run() {
mDrawerToggle.syncState();
}
});
mDrawerLayout.setDrawerListener(mDrawerToggle);
}
private void selectItem(int position) {
mCurrentSelectedPosition = position;
if (mDrawerListView != null) {
mDrawerListView.setItemChecked(position, true);
}
if (mDrawerLayout != null) {
mDrawerLayout.closeDrawer(mFragmentContainerView);
}
if (mCallbacks != null) {
mCallbacks.onNavigationDrawerItemSelected(position);
}
}
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mCallbacks = (NavigationDrawerCallbacks) activity;
} catch (ClassCastException e) {
throw new ClassCastException(
"Activity must implement NavigationDrawerCallbacks.");
}
}
@Override
public void onDetach() {
super.onDetach();
mCallbacks = null;
}
@Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt(STATE_SELECTED_POSITION, mCurrentSelectedPosition);
}
@Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
// Forward the new configuration the drawer toggle component.
mDrawerToggle.onConfigurationChanged(newConfig);
}
@Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
// If the drawer is open, show the global app actions in the action bar.
// See also
// showGlobalContextActionBar, which controls the top-left area of the
// action bar.
if (mDrawerLayout != null && isDrawerOpen()) {
inflater.inflate(R.menu.global, menu);
showGlobalContextActionBar();
}
super.onCreateOptionsMenu(menu, inflater);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
if (item.getItemId() == R.id.action_example) {
Toast.makeText(getActivity(), "Example action.", Toast.LENGTH_SHORT)
.show();
return true;
}
return super.onOptionsItemSelected(item);
}
/**
* Per the navigation drawer design guidelines, updates the action bar to
* show the global app 'context', rather than just what's in the current
* screen.
*/
private void showGlobalContextActionBar() {
ActionBar actionBar = getActionBar();
actionBar.setDisplayShowTitleEnabled(true);
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
actionBar.setTitle(R.string.app_name);
}
private ActionBar getActionBar() {
return getActivity().getActionBar();
}
/**
* Callbacks interface that all activities using this fragment must
* implement.
*/
public static interface NavigationDrawerCallbacks {
/**
* Called when an item in the navigation drawer is selected.
*/
void onNavigationDrawerItemSelected(int position);
}
}