本文介绍了自实施FragmentTabHost的的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我在执行嵌套的片段在我的应用程序中使用新的API 17，它提供了一个 FragmentTabHost 这样做。不过，我有一个父片段在我的简单的2片片段，一些基本的事情就麻烦了：
- 我想嵌套的标签是在底部（视图1和视图2片）
- 在我想自定义的实际标签看起来不同于标准
有没有人与这些工作过，知道如何实现这一目标？这里的样品code，我有启动并运行：
进口android.os.Bundle;
进口android.support.v4.app.Fragment;
进口android.support.v4.app.FragmentTabHost;
进口android.view.LayoutInflater;
进口android.view.View;
进口android.view.ViewGroup;
公共类FragmentTabsFragmentSupport扩展片段{
私人FragmentTabHost mTabHost;
@覆盖
公共查看onCreateView（LayoutInflater充气，容器的ViewGroup，
捆绑savedInstanceState）{
mTabHost =新FragmentTabHost（getActivity（））;
mTabHost.setup（getActivity（），getChildFragmentManager（），R.id.fragment1）;
mTabHost.addTab（mTabHost.newTabSpec（TAB1）。setIndicator（简单），
NestedFragment1.class，NULL）;
mTabHost.addTab（mTabHost.newTabSpec（TAB2）。setIndicator（联系人），
NestedFragment2.class，NULL）;
返回mTabHost;
}
@覆盖
公共无效onDestroyView（）{
super.onDestroyView（）;
mTabHost = NULL;
}
}
我曾尝试以下操作以底部对齐选项卡，但没有运气：
TabWidget mTabWidget = mTabHost.getTabWidget（）;
mTabWidget.setGravity（Gravity.BOTTOM）;
mTabWidget.setVerticalGravity（Gravity.BOTTOM）;
解决方案
我终于到了这条底线。有一个问题FragmentTabHost.java这将总是创建一个TabHost的元素对你来说，不管你的XML定义和膨胀事先。
因此，我写我自己的版本FragmentTabHost.java时注释掉code部分。
请务必使用这个新的版本，在你的XML布局，＆LT; com.example.app.MyFragmentTabHost
当然它充气：
Fragment1.java：
mTabHost =（MyFragmentTabHost）view.findViewById（android.R.id.tabhost）;
mTabHost.setup（getActivity（），getChildFragmentManager（），android.R.id.tabcontent）;
MyFragmentTabHost.java：
包com.example.app;
进口的java.util.ArrayList;
进口android.content.Context;
进口android.content.res.TypedArray;
进口android.os.Bundle;
进口android.os.Parcel;
进口android.os.Parcelable;
进口android.support.v4.app.Fragment;
进口android.support.v4.app.FragmentManager;
进口android.support.v4.app.FragmentTransaction;
进口android.util.AttributeSet;
进口android.view.View;
进口android.widget.FrameLayout;
进口android.widget.TabHost;
/ **
*特别TabHost，允许使用{@link片段}对象为
*它的标签内容。当在一个视图层次结构将这个，充气后
*您必须调用层次{@link #setup（背景下，FragmentManager，INT）}
*以完成标签主机的初始化。
*
* /
公共类MyFragmentTabHost扩展TabHost
实现TabHost.OnTabChangeListener {
私人最终的ArrayList＆LT; TabInfo＆GT; mTabs =新的ArrayList＆LT; TabInfo＆GT;（）;
私人的FrameLayout mRealTabContent;
私人语境mContext;
私人FragmentManager mFragmentManager;
私人诠释mContainerId;
私人TabHost.OnTabChangeListener mOnTabChangeListener;
私人TabInfo mLastTab;
私人布尔mAttached;
静态final类TabInfo {
私人最终字符串标记;
私人最终类别＆LT;＆GT; CLSS;
私人最终捆绑的args;
私人片段片段;
TabInfo（字符串_tag，类＆LT;＆GT; _class，捆绑_args）{
标签= _tag;
CLSS = _class;
的args = _args;
}
}
静态类DummyTabFactory实现TabHost.TabContentFactory {
私人最终语境mContext;
公共DummyTabFactory（上下文的背景下）{
mContext =背景;
}
@覆盖
公共查看createTabContent（字符串变量）{
视图V =新景（mContext）;
v.setMinimumWidth（0）;
v.setMinimumHeight（0）;
返回伏;
}
}
静态类SavedState扩展BaseSavedState {
字符串curTab;
SavedState（Parcelable超级大国）{
超（超国家）;
}
私人SavedState（包裹中）{
超级（在）;
curTab = in.readString（）;
}
@覆盖
公共无效writeToParcel（包裹出来，诠释标志）{
super.writeToParcel（满分，旗）;
out.writeString（curTab）;
}
@覆盖
公共字符串的toString（）{
回归FragmentTabHost.SavedState {
+ Integer.toHexString（System.identityHash code（本））
+curTab =+ curTab +};
}
公共静态最终Parcelable.Creator＆LT; SavedState＆GT; CREATOR
=新Parcelable.Creator＆LT; SavedState＆GT;（）{
公共SavedState createFromParcel（包裹中）{
返回新SavedState（中）;
}
公共SavedState [] newArray（INT尺寸）{
返回新SavedState【尺寸】;
}
};
}
公共MyFragmentTabHost（上下文的背景下）{
//请注意，我们通过对接受一个的AttributeSet版本打电话，
//因为简单的上下文结构可能会导致在一个破碎的对象！
超（背景下，NULL）;
initFragmentTabHost（背景下，NULL）;
}
公共MyFragmentTabHost（上下文的背景下，ATTRS的AttributeSet）{
超（背景下，ATTRS）;
initFragmentTabHost（背景下，ATTRS）;
}
私人无效initFragmentTabHost（上下文的背景下，ATTRS的AttributeSet）{
TypedArray A = context.obtainStyledAttributes（ATTRS，
新INT [] {android.R.attr.inflatedId}，0，0）;
mContainerId = a.getResourceId（0，0）;
a.recycle（）;
super.setOnTabChangedListener（本）;
/ ***删除该功能的其余部分*** /
/ *** findViewById（android.R.id.tabs）IS NULL EVERY TIME *** /
}
/ **
* @德precated不要叫原TabHost设置，则必须改为
*电话{@link #setup（背景下，FragmentManager）}或
* {@link #setup（背景下，FragmentManager，INT）}。
* /
@覆盖@德precated
公共无效设置（）{
抛出新IllegalStateException异常（
必须呼叫建立（），需要一个语境和FragmentManager）;
}
公共无效设置（上下文的背景下，FragmentManager经理）{
super.setup（）;
mContext =背景;
mFragmentManager =经理;
ensureContent（）;
}
公共无效设置（上下文的背景下，FragmentManager经理，诠释containerId）{
super.setup（）;
mContext =背景;
mFragmentManager =经理;
mContainerId = containerId;
ensureContent（）;
mRealTabContent.setId（containerId）;
//我们必须有一个ID，以便能够保存/恢复我们的国家。如果
//店主并没有设置一个在这一点上，我们将它设置我们自己。
如果（的getId（）== View.NO_ID）{
SETID（android.R.id.tabhost）;
}
}
私人无效ensureContent（）{
如果（mRealTabContent == NULL）{
mRealTabContent =（的FrameLayout）findViewById（mContainerId）;
如果（mRealTabContent == NULL）{
抛出新IllegalStateException异常（
无标签内容的FrameLayout发现号+ mContainerId）;
}
}
}
@覆盖
公共无效setOnTabChangedListener（OnTabChangeListener L）{
mOnTabChangeListener =升;
}
公共无效addTab（TabHost.TabSpec则tabspec，类＆LT;＆GT; CLSS，捆绑参数）{
tabSpec.setContent（新DummyTabFactory（mContext））;
字符串变量= tabSpec.getTag（）;
TabInfo信息=新TabInfo（标签，CLSS，参数）;
如果（mAttached）{
//如果我们已经贴在窗户上，然后进行检查，以
//确保该选项卡的片段是无效的，如果它的存在。这不应该
//通常发生。
info.fragment = mFragmentManager.findFragmentByTag（标签）;
如果（info.fragment =空＆安培;！＆安培;！info.fragment.isDetached（））{
FragmentTransaction英尺= mFragmentManager.beginTransaction（）;
ft.detach（info.fragment）;
ft.commit（）;
}
}
mTabs.add（信息）;
addTab（则tabspec）;
}
@覆盖
保护无效onAttachedToWindow（）{
super.onAttachedToWindow（）;
串currentTab = getCurrentTabTag（）;
//遍历所有选项卡，并确保他们的片段匹配
//正确的状态。
FragmentTransaction英尺= NULL;
的for（int i = 0; I＆LT; mTabs.size（）;我++）{
TabInfo标签= mTabs.get（我）;
tab.fragment = mFragmentManager.findFragmentByTag（tab.tag）;
如果（tab.fragment =空＆安培;！＆安培;！tab.fragment.isDetached（））{
如果（tab.tag.equals（currentTab））{
//片段为这个标签已经存在和
//活跃，这是我们真正想拥有
//为当前选项卡。没事做。
mLastTab =标签;
} 其他 {
//将该片段恢复在激活状态，
//而不是当前选项卡。停用。
如果（英尺== NULL）{
英尺= mFragmentManager.beginTransaction（）;
}
ft.detach（tab.fragment）;
}
}
}
//我们现在可以走了。确保我们切换到
//正确的选项卡。
mAttached = TRUE;
FT = doTabChanged（currentTab，英尺）;
如果（英尺！= NULL）{
ft.commit（）;
mFragmentManager.executePendingTransactions（）;
}
}
@覆盖
保护无效onDetachedFromWindow（）{
super.onDetachedFromWindow（）;
mAttached = FALSE;
}
@覆盖
保护Parcelable的onSaveInstanceState（）{
Parcelable超级大国= super.onSaveInstanceState（）;
SavedState SS =新SavedState（覆）;
ss.curTab = getCurrentTabTag（）;
返回SS;
}
@覆盖
保护无效onRestoreInstanceState（Parcelable州）{
SavedState SS =（SavedState）状态;
super.onRestoreInstanceState（ss.getSuperState（））;
setCurrentTabByTag（ss.curTab）;
}
@覆盖
公共无效onTabChanged（字符串tabId）{
如果（mAttached）{
FragmentTransaction英尺= doTabChanged（tabId，NULL）;
如果（英尺！= NULL）{
ft.commit（）;
}
}
如果（mOnTabChangeListener！= NULL）{
mOnTabChangeListener.onTabChanged（tabId）;
}
}
私人FragmentTransaction doTabChanged（字符串tabId，FragmentTransaction英尺）{
TabInfo newTab = NULL;
的for（int i = 0; I＆LT; mTabs.size（）;我++）{
TabInfo标签= mTabs.get（我）;
如果（tab.tag.equals（tabId））{
newTab =标签;
}
}
如果（newTab == NULL）{
抛出新IllegalStateException异常（无标签闻名的标记+ tabId）;
}
如果（mLastTab！= newTab）{
如果（英尺== NULL）{
英尺= mFragmentManager.beginTransaction（）;
}
如果（mLastTab！= NULL）{
如果（mLastTab.fragment！= NULL）{
ft.detach（mLastTab.fragment）;
}
}
如果（newTab！= NULL）{
如果（newTab.fragment == NULL）{
newTab.fragment = Fragment.instantiate（mContext，
newTab.clss.getName（），newTab.args）;
ft.add（mContainerId，newTab.fragment，newTab.tag）;
} 其他 {
ft.attach（newTab.fragment）;
}
}
mLastTab = newTab;
}
返回英尺;
}
}
I am implementing nested fragments in my app using the new API 17, which provides a FragmentTabHost for doing so. However, I'm having trouble with a few basic things for my simple 2 tab fragments inside a parent fragment:
- I would like the nested tabs to be at the bottom (View1 and View2 tabs)
- I would like to customize the actual tabs to look different than standard
Has anyone worked with these before and know how to achieve this? Here's the sample code which I have up and running:
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentTabHost;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
public class FragmentTabsFragmentSupport extends Fragment {
private FragmentTabHost mTabHost;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
mTabHost = new FragmentTabHost(getActivity());
mTabHost.setup(getActivity(), getChildFragmentManager(), R.id.fragment1);
mTabHost.addTab(mTabHost.newTabSpec("Tab1").setIndicator("Simple"),
NestedFragment1.class, null);
mTabHost.addTab(mTabHost.newTabSpec("Tab2").setIndicator("Contacts"),
NestedFragment2.class, null);
return mTabHost;
}
@Override
public void onDestroyView() {
super.onDestroyView();
mTabHost = null;
}
}
I have tried the following to bottom align the tabs, but no luck:
TabWidget mTabWidget = mTabHost.getTabWidget();
mTabWidget.setGravity(Gravity.BOTTOM);
mTabWidget.setVerticalGravity(Gravity.BOTTOM);
解决方案
I finally got to the bottom of this. There is an issue with FragmentTabHost.java which will always create a TabHost element for you, no matter what you define in XML and inflate beforehand.
As such, I commented out that part of code when writing my own version of FragmentTabHost.java.
Make sure to use your new version of this in your XML layout, <com.example.app.MyFragmentTabHost
And of course inflate it:
Fragment1.java:
mTabHost = (MyFragmentTabHost) view.findViewById(android.R.id.tabhost);
mTabHost.setup(getActivity(), getChildFragmentManager(), android.R.id.tabcontent);
MyFragmentTabHost.java:
package com.example.app;
import java.util.ArrayList;
import android.content.Context;
import android.content.res.TypedArray;
import android.os.Bundle;
import android.os.Parcel;
import android.os.Parcelable;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.util.AttributeSet;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.TabHost;
/**
* Special TabHost that allows the use of {@link Fragment} objects for
* its tab content. When placing this in a view hierarchy, after inflating
* the hierarchy you must call {@link #setup(Context, FragmentManager, int)}
* to complete the initialization of the tab host.
*
*/
public class MyFragmentTabHost extends TabHost
implements TabHost.OnTabChangeListener {
private final ArrayList<TabInfo> mTabs = new ArrayList<TabInfo>();
private FrameLayout mRealTabContent;
private Context mContext;
private FragmentManager mFragmentManager;
private int mContainerId;
private TabHost.OnTabChangeListener mOnTabChangeListener;
private TabInfo mLastTab;
private boolean mAttached;
static final class TabInfo {
private final String tag;
private final Class<?> clss;
private final Bundle args;
private Fragment fragment;
TabInfo(String _tag, Class<?> _class, Bundle _args) {
tag = _tag;
clss = _class;
args = _args;
}
}
static class DummyTabFactory implements TabHost.TabContentFactory {
private final Context mContext;
public DummyTabFactory(Context context) {
mContext = context;
}
@Override
public View createTabContent(String tag) {
View v = new View(mContext);
v.setMinimumWidth(0);
v.setMinimumHeight(0);
return v;
}
}
static class SavedState extends BaseSavedState {
String curTab;
SavedState(Parcelable superState) {
super(superState);
}
private SavedState(Parcel in) {
super(in);
curTab = in.readString();
}
@Override
public void writeToParcel(Parcel out, int flags) {
super.writeToParcel(out, flags);
out.writeString(curTab);
}
@Override
public String toString() {
return "FragmentTabHost.SavedState{"
+ Integer.toHexString(System.identityHashCode(this))
+ " curTab=" + curTab + "}";
}
public static final Parcelable.Creator<SavedState> CREATOR
= new Parcelable.Creator<SavedState>() {
public SavedState createFromParcel(Parcel in) {
return new SavedState(in);
}
public SavedState[] newArray(int size) {
return new SavedState[size];
}
};
}
public MyFragmentTabHost(Context context) {
// Note that we call through to the version that takes an AttributeSet,
// because the simple Context construct can result in a broken object!
super(context, null);
initFragmentTabHost(context, null);
}
public MyFragmentTabHost(Context context, AttributeSet attrs) {
super(context, attrs);
initFragmentTabHost(context, attrs);
}
private void initFragmentTabHost(Context context, AttributeSet attrs) {
TypedArray a = context.obtainStyledAttributes(attrs,
new int[] { android.R.attr.inflatedId }, 0, 0);
mContainerId = a.getResourceId(0, 0);
a.recycle();
super.setOnTabChangedListener(this);
/*** REMOVE THE REST OF THIS FUNCTION ***/
/*** findViewById(android.R.id.tabs) IS NULL EVERY TIME ***/
}
/**
* @deprecated Don't call the original TabHost setup, you must instead
* call {@link #setup(Context, FragmentManager)} or
* {@link #setup(Context, FragmentManager, int)}.
*/
@Override @Deprecated
public void setup() {
throw new IllegalStateException(
"Must call setup() that takes a Context and FragmentManager");
}
public void setup(Context context, FragmentManager manager) {
super.setup();
mContext = context;
mFragmentManager = manager;
ensureContent();
}
public void setup(Context context, FragmentManager manager, int containerId) {
super.setup();
mContext = context;
mFragmentManager = manager;
mContainerId = containerId;
ensureContent();
mRealTabContent.setId(containerId);
// We must have an ID to be able to save/restore our state. If
// the owner hasn't set one at this point, we will set it ourself.
if (getId() == View.NO_ID) {
setId(android.R.id.tabhost);
}
}
private void ensureContent() {
if (mRealTabContent == null) {
mRealTabContent = (FrameLayout)findViewById(mContainerId);
if (mRealTabContent == null) {
throw new IllegalStateException(
"No tab content FrameLayout found for id " + mContainerId);
}
}
}
@Override
public void setOnTabChangedListener(OnTabChangeListener l) {
mOnTabChangeListener = l;
}
public void addTab(TabHost.TabSpec tabSpec, Class<?> clss, Bundle args) {
tabSpec.setContent(new DummyTabFactory(mContext));
String tag = tabSpec.getTag();
TabInfo info = new TabInfo(tag, clss, args);
if (mAttached) {
// If we are already attached to the window, then check to make
// sure this tab's fragment is inactive if it exists. This shouldn't
// normally happen.
info.fragment = mFragmentManager.findFragmentByTag(tag);
if (info.fragment != null && !info.fragment.isDetached()) {
FragmentTransaction ft = mFragmentManager.beginTransaction();
ft.detach(info.fragment);
ft.commit();
}
}
mTabs.add(info);
addTab(tabSpec);
}
@Override
protected void onAttachedToWindow() {
super.onAttachedToWindow();
String currentTab = getCurrentTabTag();
// Go through all tabs and make sure their fragments match
// the correct state.
FragmentTransaction ft = null;
for (int i=0; i<mTabs.size(); i++) {
TabInfo tab = mTabs.get(i);
tab.fragment = mFragmentManager.findFragmentByTag(tab.tag);
if (tab.fragment != null && !tab.fragment.isDetached()) {
if (tab.tag.equals(currentTab)) {
// The fragment for this tab is already there and
// active, and it is what we really want to have
// as the current tab. Nothing to do.
mLastTab = tab;
} else {
// This fragment was restored in the active state,
// but is not the current tab. Deactivate it.
if (ft == null) {
ft = mFragmentManager.beginTransaction();
}
ft.detach(tab.fragment);
}
}
}
// We are now ready to go. Make sure we are switched to the
// correct tab.
mAttached = true;
ft = doTabChanged(currentTab, ft);
if (ft != null) {
ft.commit();
mFragmentManager.executePendingTransactions();
}
}
@Override
protected void onDetachedFromWindow() {
super.onDetachedFromWindow();
mAttached = false;
}
@Override
protected Parcelable onSaveInstanceState() {
Parcelable superState = super.onSaveInstanceState();
SavedState ss = new SavedState(superState);
ss.curTab = getCurrentTabTag();
return ss;
}
@Override
protected void onRestoreInstanceState(Parcelable state) {
SavedState ss = (SavedState)state;
super.onRestoreInstanceState(ss.getSuperState());
setCurrentTabByTag(ss.curTab);
}
@Override
public void onTabChanged(String tabId) {
if (mAttached) {
FragmentTransaction ft = doTabChanged(tabId, null);
if (ft != null) {
ft.commit();
}
}
if (mOnTabChangeListener != null) {
mOnTabChangeListener.onTabChanged(tabId);
}
}
private FragmentTransaction doTabChanged(String tabId, FragmentTransaction ft) {
TabInfo newTab = null;
for (int i=0; i<mTabs.size(); i++) {
TabInfo tab = mTabs.get(i);
if (tab.tag.equals(tabId)) {
newTab = tab;
}
}
if (newTab == null) {
throw new IllegalStateException("No tab known for tag " + tabId);
}
if (mLastTab != newTab) {
if (ft == null) {
ft = mFragmentManager.beginTransaction();
}
if (mLastTab != null) {
if (mLastTab.fragment != null) {
ft.detach(mLastTab.fragment);
}
}
if (newTab != null) {
if (newTab.fragment == null) {
newTab.fragment = Fragment.instantiate(mContext,
newTab.clss.getName(), newTab.args);
ft.add(mContainerId, newTab.fragment, newTab.tag);
} else {
ft.attach(newTab.fragment);
}
}
mLastTab = newTab;
}
return ft;
}
}
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