将片段分配给具有不同方向的 ActionBar 中的选项卡 [英] Assigning Fragments to tabs in the ActionBar with different orientations
问题描述
我有 3 个片段和一个活动.我想启用 ActionBar 上的选项卡并将 Fragment 分配给 3 个选项卡中的每一个.如何正确连接?
I have 3 fragments and an activity. I want to enable tabs on the ActionBar and assign a Fragment to each of the 3 tabs. How do I hook that up correctly?
原帖
我正在开发一个应用，使用 Google I/O 应用作为指南.我已经在 ActionBar 中实现了选项卡.他们似乎一直在工作，直到平板电脑的方向发生变化.例如，所有 3 个选项卡都有一个 Fragment.我可以很好地在它们之间切换，但是当我改变方向时，无论我上次查看的 Fragment 保持可见，但单击选项卡不再改变视图......就像它们已断开连接一样.正如预期的那样，回到原来的方向并不能修复"它.
I have an app that I'm developing using the Google I/O app as a guide. I've implemented tabs into the ActionBar. They seem to be working until the tablet's orientation changes. For example, all 3 tabs have a Fragment. I can switch between them just fine, but when I change the orientation, whatever the Fragment I was last viewing stays visible, but clicking the tabs no longer changes the view... like they have become disconnected. As expected, going back to the original orientation does not "fix" it.
我已经研究过保存和恢复状态，但我不知道这些会有什么帮助.
I've looked into saving and restoring state, but I'm not seeing how those would help.
编辑
模块级别:
Fragment mFragmentA = (Fragment) new AFragmentTab();
Fragment mFragmentB = (Fragment) new BFragmentTab();
Fragment mFragmentC = (Fragment) new CFragmentTab();
我在活动的 onCreate 中有这样的东西:
I have something like this in the activity's onCreate:
ActionBar actionBar = getActionBar();
actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
actionBar.setDisplayShowTitleEnabled(false);
ActionBar.Tab tabA = actionBar.newTab().setText("text a");
ActionBar.Tab tabB = actionBar.newTab().setText("text b");
ActionBar.Tab tabC = actionBar.newTab().setText("text c");
tabA.setTabListener(this);
tabB.setTabListener(this);
tabC.setTabListener(this);
actionBar.addTab(tabA);
actionBar.addTab(tabB);
actionBar.addTab(tabC);
还有一个 TabListener 像这样:
编辑已删除
class MyTabListener implements ActionBar.TabListener {
private Fragment mFragment;
// Called to create an instance of the listener when adding a new tab
public MyTabListener(Fragment fragment) {
mFragment = fragment;
}
public void onTabSelected(Tab tab, FragmentTransaction ft) {
ft.add(R.id.fragment_content, mFragment, null);
}
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
ft.remove(mFragment);
}
public void onTabReselected(Tab tab, FragmentTransaction ft) {
// do nothing
}
}
编辑
我已经移动了 TabListener.我没有将它作为一个单独的类，而是在 Activity 上实现了 TabListener.然后在 Selected 和 Unselected 方法上，我有类似的东西:
I've moved the TabListener. Instead of it being a separate class, I implement the TabListener on the Activity. Then on the Selected and Unselected methods I have something like:
public void onTabSelected(Tab tab, FragmentTransaction ft) {
switch (tab.getPosition()) {
case 0:
ft.add(R.id.fragment_content, mFragmentA, null);
break;
case 1:
ft.add(R.id.fragment_content, mFragmentB, null);
break;
case 2:
ft.add(R.id.fragment_content, mFragmentC, null);
break;
}
}
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
switch (tab.getPosition()) {
case 0:
ft.remove(mFragmentA);
break;
case 1:
ft.remove(mFragmentB);
break;
case 2:
ft.remove(mFragmentC);
break;
}
}
它仍然在做同样的事情.我真的不知道发生了什么.
It's still doing the same thing. I really don't know what's happening.
推荐答案
看来我的答案可以在这里找到:http://developer.android.com/resources/samples/ApiDemos/src/com/example/android/apis/app/FragmentTabs.html
It looks like my answer can be found here: http://developer.android.com/resources/samples/ApiDemos/src/com/example/android/apis/app/FragmentTabs.html
/*
* Copyright (C) 2011 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.apis.app;
import com.example.android.apis.R;
import android.app.ActionBar;
import android.app.ActionBar.Tab;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.widget.Toast;
/**
* This demonstrates the use of action bar tabs and how they interact
* with other action bar features.
*/
public class FragmentTabs extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
final ActionBar bar = getActionBar();
bar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
bar.setDisplayOptions(0, ActionBar.DISPLAY_SHOW_TITLE);
bar.addTab(bar.newTab()
.setText("Simple")
.setTabListener(new TabListener<FragmentStack.CountingFragment>(
this, "simple", FragmentStack.CountingFragment.class)));
bar.addTab(bar.newTab()
.setText("Contacts")
.setTabListener(new TabListener<LoaderCursor.CursorLoaderListFragment>(
this, "contacts", LoaderCursor.CursorLoaderListFragment.class)));
bar.addTab(bar.newTab()
.setText("Apps")
.setTabListener(new TabListener<LoaderCustom.AppListFragment>(
this, "apps", LoaderCustom.AppListFragment.class)));
bar.addTab(bar.newTab()
.setText("Throttle")
.setTabListener(new TabListener<LoaderThrottle.ThrottledLoaderListFragment>(
this, "throttle", LoaderThrottle.ThrottledLoaderListFragment.class)));
if (savedInstanceState != null) {
bar.setSelectedNavigationItem(savedInstanceState.getInt("tab", 0));
}
}
@Override
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("tab", getActionBar().getSelectedNavigationIndex());
}
public static class TabListener<T extends Fragment> implements ActionBar.TabListener {
private final Activity mActivity;
private final String mTag;
private final Class<T> mClass;
private final Bundle mArgs;
private Fragment mFragment;
public TabListener(Activity activity, String tag, Class<T> clz) {
this(activity, tag, clz, null);
}
public TabListener(Activity activity, String tag, Class<T> clz, Bundle args) {
mActivity = activity;
mTag = tag;
mClass = clz;
mArgs = args;
// Check to see if we already have a fragment for this tab, probably
// from a previously saved state. If so, deactivate it, because our
// initial state is that a tab isn't shown.
mFragment = mActivity.getFragmentManager().findFragmentByTag(mTag);
if (mFragment != null && !mFragment.isDetached()) {
FragmentTransaction ft = mActivity.getFragmentManager().beginTransaction();
ft.hide(mFragment);
ft.commit();
}
}
public void onTabSelected(Tab tab, FragmentTransaction ft) {
if (mFragment == null) {
mFragment = Fragment.instantiate(mActivity, mClass.getName(), mArgs);
ft.add(android.R.id.content, mFragment, mTag);
} else {
ft.show(mFragment);
}
}
public void onTabUnselected(Tab tab, FragmentTransaction ft) {
if (mFragment != null) {
ft.hide(mFragment);
}
}
public void onTabReselected(Tab tab, FragmentTransaction ft) {
Toast.makeText(mActivity, "Reselected!", Toast.LENGTH_SHORT).show();
}
}
}
这篇关于将片段分配给具有不同方向的 ActionBar 中的选项卡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！
