我不知道为什么调用在其他屏幕（第二屏幕）之前显示的屏幕（第一屏幕）。我想删除第一个屏幕。在非常短的时间内（<3ms）显示拳头屏幕。我不想看到它。我的项目是从link下载的。
主要活动：
/*
* Copyright 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
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.os.SystemClock;
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;
/**
* This example illustrates a common usage of the DrawerLayout widget
* in the Android support library.
* <p/>
* <p>When a navigation (left) drawer is present, the host activity should detect presses of
* the action bar's Up affordance as a signal to open and close the navigation drawer. The
* ActionBarDrawerToggle facilitates this behavior.
* Items within the drawer should fall into one of two categories:</p>
* <p/>
* <ul>
* <li><strong>View switches</strong>. A view switch follows the same basic policies as
* list or tab navigation in that a view switch does not create navigation history.
* This pattern should only be used at the root activity of a task, leaving some form
* of Up navigation active for activities further down the navigation hierarchy.</li>
* <li><strong>Selective Up</strong>. The drawer allows the user to choose an alternate
* parent for Up navigation. This allows a user to jump across an app's navigation
* hierarchy at will. The application should treat this as it treats Up navigation from
* a different task, replacing the current task stack using TaskStackBuilder or similar.
* This is the only form of navigation drawer that should be used outside of the root
* activity of a task.</li>
* </ul>
* <p/>
* <p>Right side drawers should be used for actions, not navigation. This follows the pattern
* established by the Action Bar that navigation should be to the left and actions to the right.
* An action should be an operation performed on the current contents of the window,
* for example enabling or disabling a data overlay on top of the current content.</p>
*/
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) {
SystemClock.sleep(3000);
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;
}
}
}
Android Manifest：
<!--
Copyright 2013 The Android Open Source Project
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.android.navigationdrawerexample"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk android:minSdkVersion="14" android:targetSdkVersion="17" />
<application
android:label="@string/app_name"
android:icon="@drawable/ic_launcher"
android:theme="@android:style/Theme.Holo.Light.DarkActionBar">
<activity
android:name=".MainActivity"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
activity_main.xml中：
<!--
Copyright 2013 The Android Open Source Project
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<!-- A DrawerLayout is intended to be used as the top-level content view using match_parent for both width and height to consume the full space available. -->
<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" >
<!--
As the main content view, the view below consumes the entire
space available using match_parent in both dimensions.
-->
<FrameLayout
android:id="@+id/content_frame"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<!--
android:layout_gravity="start" tells DrawerLayout to treat
this as a sliding drawer on the left side for left-to-right
languages and on the right side for right-to-left languages.
The drawer is given a fixed width in dp and extends the full height of
the container. A solid background is used for contrast
with the content view.
-->
<ListView
android:id="@+id/left_drawer"
android:layout_width="280dp"
android:layout_height="514dp"
android:layout_gravity="start"
android:background="#6d386f"
android:choiceMode="singleChoice"
android:divider="@android:color/transparent"
android:dividerHeight="0dp" />
<RelativeLayout
android:layout_width="fill_parent"
android:layout_height="51dp"
android:layout_marginBottom="0dp"
android:layout_marginTop="514dp"
android:background="#6d386f" >
<Button
android:id="@+id/draw_btn"
android:layout_width="42dp"
android:layout_height="42dp"
android:layout_marginLeft="15dp"
android:background="@drawable/draw_btn" />
<Button
android:id="@+id/puzzle_btn"
android:layout_width="42dp"
android:layout_height="42dp"
android:layout_marginLeft="28dp"
android:layout_toRightOf="@id/draw_btn"
android:background="@drawable/puzzle_btn" />
<Button
android:id="@+id/keyboard_btn"
android:layout_width="47dp"
android:layout_height="28dp"
android:layout_marginLeft="32dp"
android:layout_marginTop="7dp"
android:layout_toRightOf="@id/puzzle_btn"
android:background="@drawable/keyboard_btn" />
<Button
android:id="@+id/mic_btn"
android:layout_width="42dp"
android:layout_height="42dp"
android:layout_marginLeft="27dp"
android:layout_toRightOf="@id/keyboard_btn"
android:background="@drawable/mic_btn" />
<Button
android:id="@+id/cam_btn"
android:layout_width="42dp"
android:layout_height="42dp"
android:layout_marginLeft="27dp"
android:layout_toRightOf="@id/mic_btn"
android:background="@drawable/cam_btn" />
</RelativeLayout>
</android.support.v4.widget.DrawerLayout>
drawer_list_item.xml
<!--
Copyright 2013 The Android Open Source Project
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<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"/>
fragment_planet.xml
<!--
Copyright 2013 The Android Open Source Project
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
-->
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ImageView
android:id="@+id/image"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#000000"
android:gravity="center"
android:padding="32dp" />
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hi"/>
</RelativeLayout>
请帮帮我。
谢谢你。
答案 0 :(得分：0)
我猜“在非常短的时间内显示的第一个屏幕（<3ms）”是导航片段已经关闭之后的滞后，恰好在所示的“行星”之前。这是此示例的常见错误（或其他）。
我已修复如下：
首先，我添加一个新的Handler和一个Runnable来“在另一个线程中完成工作”（正如我猜的那样）。
private Handler mHandler;
private Runnable mPendingRunnable;
然后，我修改了以下方法：
/* The click listner for ListView in the navigation drawer */
private class DrawerItemClickListener implements ListView.OnItemClickListener {
@Override
public void onItemClick(AdapterView<?> parent, View view, final int position, long id) {
mPendingRunnable = new Runnable() {
@Override
public void run() {
// update selected item and title, then close the drawer
// 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();
}
};
mDrawerList.setItemChecked(position, true);
setTitle(mPlanetTitles[position]);
mDrawerLayout.closeDrawer(mDrawerList);
}
}
//
public void onDrawerClosed(View view) {
getActionBar().setTitle(mTitle);
invalidateOptionsMenu(); // creates call to onPrepareOptionsMenu()
if (mPendingRunnable != null) {
mHandler.post(mPendingRunnable);
mPendingRunnable = null;
}
}
现在，您的导航窗格应平滑关闭，关闭后，行星将立即显示。
关于结束/开放过程的持续时间，您应该阅读此主题以获取更多信息：
Speed up 'Navigation Drawer' animation speed on closing?
所以，基本上，我的答案将在结束时清除导航窗格的延迟。