- 目前側(cè)滑菜單已廣泛應(yīng)用于各大應(yīng)用棍弄,這一菜單形式簡潔明了倚喂,深受用戶的喜愛墨状。在谷歌官方推出 DrawerLayout 之前,開發(fā)者大都通過 SlidingMenu 開源庫來實現(xiàn)這一功能柑爸。而現(xiàn)在 DrawerLayout 被谷歌包含在了 android-support-v4.jar 這個包下,可以讓開發(fā)者更簡單方便的實現(xiàn)側(cè)滑菜單這一功能盒音。
- Google I/O 2013Android更新了Support庫表鳍,Support Library包中實現(xiàn)了側(cè)滑菜單效果的控件---drawerLayout馅而,支持創(chuàng)建 Navigation Drawer(導(dǎo)航抽屜)模式。
- drawerLayout其實是一個布局控件进胯,跟LinearLayout等控件是一種東西用爪,但是drawerLayout帶有滑動的功能。只要按照drawerLayout的規(guī)定布局方式寫完布局胁镐,就能有側(cè)滑的效果偎血。
- drawerLayout分為側(cè)邊菜單和主內(nèi)容區(qū)兩部分,側(cè)邊菜單可以根據(jù)手勢展開與隱藏(drawerLayout自身特性)盯漂,主內(nèi)容區(qū)的內(nèi)容可以隨著菜單的點(diǎn)擊而變化(這需要使用者自己實現(xiàn))颇玷。這個東西主要的原理就是左邊是一個ListView(抽屜菜單),右邊是一個FrameLayout.(用來顯示頁面的主要內(nèi)容)就缆。
- 在需要抽屜菜單的界面帖渠,用DrawerLayout 作為界面根控件。在DrawerLayout里面第一個View為當(dāng)前界面主內(nèi)容竭宰;第二個和第三個View為抽屜菜單內(nèi)容空郊。如果當(dāng)前界面只需要一個抽屜菜單,則第三個View可以省略
- 具體可參考以下鏈接切揭,官方的開發(fā)頁是:
Android Navigation Drawer Design :
http://developer.android.com/design/patterns/navigation-drawer.html
Android Navigation Drawer 教程:
https://developer.android.com/training/implementing-navigation/nav-drawer.html(包含官方Demo的實例 大家也可以自己下載看一下)
接下來附上完整的drawerLayout的例子狞甚,來源于官方網(wǎng)站的demo
Activity:
package com.example.android.navigationdrawerexample;
import java.util.Locale;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.SearchManager;
import android.content.Intent;
import android.content.res.Configuration;
import android.os.Bundle;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
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.ImageView;
import android.widget.ListView;
import android.widget.Toast;
public class MainActivity extends Activity {
private DrawerLayout mDrawerLayout;
private ListView mDrawerList;
private ActionBarDrawerToggle mDrawerToggle;
private CharSequence mDrawerTitle;
private CharSequence mTitle;
private String[] mPlanetTitles;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTitle = mDrawerTitle = getTitle();
mPlanetTitles = getResources().getStringArray(R.array.planets_array);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
mDrawerList = (ListView) findViewById(R.id.left_drawer);
// 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
mDrawerList.setAdapter(new ArrayAdapter<String>(this,
R.layout.drawer_list_item, mPlanetTitles));
mDrawerList.setOnItemClickListener(new DrawerItemClickListener());
// enable ActionBar app icon to behave as action to toggle nav drawer
getActionBar().setDisplayHomeAsUpEnabled(true);
getActionBar().setHomeButtonEnabled(true);
// ActionBarDrawerToggle ties together the the proper interactions
// between the sliding drawer and the action bar app icon
mDrawerToggle = new ActionBarDrawerToggle(
this, /* host Activity */
mDrawerLayout, /* DrawerLayout object */
R.drawable.ic_drawer, /* nav drawer image to replace 'Up' caret */
R.string.drawer_open, /* "open drawer" description for accessibility */
R.string.drawer_close /* "close drawer" description for accessibility */
) {
public void onDrawerClosed(View view) {
getActionBar().setTitle(mTitle);
invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
}
public void onDrawerOpened(View drawerView) {
getActionBar().setTitle(mDrawerTitle);
invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
}
};
mDrawerLayout.setDrawerListener(mDrawerToggle);
if (savedInstanceState == null) {
selectItem(0);
}
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main, menu);
return super.onCreateOptionsMenu(menu);
}
/* Called whenever we call invalidateOptionsMenu() */
@Override
public boolean onPrepareOptionsMenu(Menu menu) {
// If the nav drawer is open, hide action items related to the content view
boolean drawerOpen = mDrawerLayout.isDrawerOpen(mDrawerList);
menu.findItem(R.id.action_websearch).setVisible(!drawerOpen);
return super.onPrepareOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// The action bar home/up action should open or close the drawer.
// ActionBarDrawerToggle will take care of this.
if (mDrawerToggle.onOptionsItemSelected(item)) {
return true;
}
// Handle action buttons
switch(item.getItemId()) {
case R.id.action_websearch:
// create intent to perform web search for this planet
Intent intent = new Intent(Intent.ACTION_WEB_SEARCH);
intent.putExtra(SearchManager.QUERY, getActionBar().getTitle());
// catch event that there's no activity to handle intent
if (intent.resolveActivity(getPackageManager()) != null) {
startActivity(intent);
} else {
Toast.makeText(this, R.string.app_not_available, Toast.LENGTH_LONG).show();
}
return true;
default:
return super.onOptionsItemSelected(item);
}
}
/* The click listner for ListView in the navigation drawer */
private class DrawerItemClickListener implements ListView.OnItemClickListener {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
selectItem(position);
}
}
private void selectItem(int position) {
// update the main content by replacing fragments
Fragment fragment = new PlanetFragment();
Bundle args = new Bundle();
args.putInt(PlanetFragment.ARG_PLANET_NUMBER, position);
fragment.setArguments(args);
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
// update selected item and title, then close the drawer
mDrawerList.setItemChecked(position, true);
setTitle(mPlanetTitles[position]);
mDrawerLayout.closeDrawer(mDrawerList);
}
@Override
public void setTitle(CharSequence title) {
mTitle = title;
getActionBar().setTitle(mTitle);
}
/**
* When using the ActionBarDrawerToggle, you must call it during
* onPostCreate() and onConfigurationChanged()...
*/
@Override
protected void onPostCreate(Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
// Sync the toggle state after onRestoreInstanceState has occurred.
mDrawerToggle.syncState();
}
@Override
public void onConfigurationChanged(Configuration newConfig) {
super.onConfigurationChanged(newConfig);
// Pass any configuration change to the drawer toggls
mDrawerToggle.onConfigurationChanged(newConfig);
}
/**
* Fragment that appears in the "content_frame", shows a planet
*/
public static class PlanetFragment extends Fragment {
public static final String ARG_PLANET_NUMBER = "planet_number";
public PlanetFragment() {
// Empty constructor required for fragment subclasses
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_planet, container, false);
int i = getArguments().getInt(ARG_PLANET_NUMBER);
String planet = getResources().getStringArray(R.array.planets_array)[i];
int imageId = getResources().getIdentifier(planet.toLowerCase(Locale.getDefault()),
"drawable", getActivity().getPackageName());
((ImageView) rootView.findViewById(R.id.image)).setImageResource(imageId);
getActivity().setTitle(planet);
return rootView;
}
}
}
Xml
activity_main.xml
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<FrameLayout
android:id="@+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<ListView
android:id="@+id/left_drawer"
android:layout_width="240dp"
android:layout_height="match_parent"
android:layout_gravity="start"
android:choiceMode="singleChoice"
android:divider="@android:color/transparent"
android:dividerHeight="0dp"
android:background="#111"/>
</android.support.v4.widget.DrawerLayout>
fragment_planet.xml
<ImageView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/image"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#000000"
android:gravity="center"
android:padding="32dp" />
drawer_list_item.xml
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@android:id/text1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceListItemSmall"
android:gravity="center_vertical"
android:paddingLeft="16dp"
android:paddingRight="16dp"
android:textColor="#fff"
android:background="?android:attr/activatedBackgroundIndicator"
android:minHeight="?android:attr/listPreferredItemHeightSmall"/>
注意的點(diǎn):
1. activity_main.xml中主內(nèi)容區(qū)的布局代碼要放在側(cè)滑菜單布局的前面,這可以幫助DrawerLayout判斷誰是側(cè)滑菜單,誰是主內(nèi)容區(qū)廓旬;側(cè)滑菜單的部分的布局(這里是ListView)可以設(shè)置layout_gravity屬性哼审,如果為"start" 即為從左往右調(diào)用菜單,如果為"end" 即為從右往左調(diào)用菜單孕豹。
2. 我們看到很多使用drawerLayout的代碼中都同時使用了Fragment涩盾,這會造成誤解,以為使用drawerLayout必須用到Fragment励背,其實這是錯誤的春霍,使用Fragment是因為在側(cè)滑菜單被點(diǎn)擊的時候,主內(nèi)容區(qū)如果內(nèi)容比較復(fù)雜叶眉,用Fragment去填充會更容易终畅,如果你的主內(nèi)容區(qū)只是一個簡單的字符串,只想在不同菜單點(diǎn)擊的時候更新一下字符串的內(nèi)容竟闪,我覺得沒必要用Fragment离福。不過官方的例子其實中,F(xiàn)ragment所做的就是更新字符串內(nèi)容這么簡單炼蛤。
**3.側(cè)邊菜單其實只是一個普通的View妖爷,一般里面裝的是ListView,看起來就像菜單,他完全可以是一個button絮识,textView等等绿聘。雖然稱為菜單,但跟Activity的菜單形式是兩碼事次舌,Activity的菜單只需要在資源文件中定義好熄攘,就能按照固定的形式顯示出來。而drawerLayout的側(cè)邊菜單顯示成什么樣完全是取決于你自己彼念,同樣點(diǎn)擊事件也完全由你自己去寫挪圾。在點(diǎn)擊側(cè)邊菜單選項的時候我們往往需要隱藏菜單來顯示整個菜單對應(yīng)的內(nèi)容。DrawerLayout.closeDrawer方法用于隱藏側(cè)邊菜單逐沙,DrawerLayout.openDrawer方法用于展開側(cè)邊菜單哲思。如下代碼 **
mDrawerList.setAdapter(new ArrayAdapter<String>(this,
R.layout.drawer_list_item, mPlanetTitles));
mDrawerList.setOnItemClickListener(new DrawerItemClickListener());
/* The click listner for ListView in the navigation drawer */
private class DrawerItemClickListener implements ListView.OnItemClickListener {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
selectItem(position);
}
}
private void selectItem(int position) {
// update the main content by replacing fragments
Fragment fragment = new PlanetFragment();
Bundle args = new Bundle();
args.putInt(PlanetFragment.ARG_PLANET_NUMBER, position);
fragment.setArguments(args);
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
// update selected item and title, then close the drawer
mDrawerList.setItemChecked(position, true);
setTitle(mPlanetTitles[position]);
mDrawerLayout.closeDrawer(mDrawerList);
}
4. view注意事項:
- 顯示界面主要內(nèi)容的View (上面的 FrameLayout ) 必須為DrawerLayout的第一個子View, 原因在于 XML 布局文件中的View順序為Android系統(tǒng)中的 z-ordering順序吩案,而抽屜必須出現(xiàn)在內(nèi)容之上棚赔。
- 顯示界面內(nèi)容的View寬度和高度設(shè)置為和父View一樣,原因在于當(dāng)抽屜菜單不可見的時候徘郭,界面內(nèi)容代表整個界面UI靠益。
- 抽屜菜單 (上面的 ListView) 必須使用android:layout_gravity屬性設(shè)置水平的 gravity值 .如果要支持 right-to-left (RTL,從右向左閱讀)語言 用 "start" 代替 "left" (當(dāng)在 RTL語言運(yùn)行時候残揉,菜單出現(xiàn)在右側(cè))捆毫。
- **抽屜菜單的寬度為 dp 單位而高度和父View一樣。抽屜菜單的寬度應(yīng)該不超過320dp冲甘,這樣用戶可以在菜單打開的時候看到部分內(nèi)容界面。 **