【移动应用开发技术】怎么在Android中利用FragmentTabHost实现一个底部菜单功能

【移动应用开发技术】怎么在Android中利用FragmentTabHost实现一个底部菜单功能

怎么在Android中利用FragmentTabHost实现一个底部菜单功能？很多新手对此不是很清楚，为了帮助大家解决这个难题，下面在下将为大家详细讲解，有这方面需求的人可以来学习下，希望你能有所收获。FragmentTabHost简单介绍首先我们看下官方文档的介绍OK，接着官方还给出了一份使用的代码，我们也来看下Activity中使用import

com.example.android.supportv4.R;

import

android.os.Bundle;

import

android.support.v4.app.FragmentActivity;

import

android.support.v4.app.FragmentTabHost;

/**

*

This

demonstrates

how

you

can

implement

switching

between

the

tabs

of

a

*

TabHost

through

fragments,

using

FragmentTabHost.

*/

public

class

FragmentTabs

extends

FragmentActivity

{

private

FragmentTabHost

mTabHost;

@Override

protected

void

onCreate(Bundle

savedInstanceState)

{

super.onCreate(savedInstanceState);

setContentView(R.layout.fragment_tabs);

mTabHost

=

(FragmentTabHost)findViewById(android.R.id.tabhost);

mTabHost.setup(this,

getSupportFragmentManager(),

R.id.realtabcontent);

mTabHost.addTab(mTabHost.newTabSpec("simple").setIndicator("Simple"),

FragmentStackSupport.CountingFragment.class,

null);

mTabHost.addTab(mTabHost.newTabSpec("contacts").setIndicator("Contacts"),

LoaderCursorSupport.CursorLoaderListFragment.class,

null);

mTabHost.addTab(mTabHost.newTabSpec("custom").setIndicator("Custom"),

LoaderCustomSupport.AppListFragment.class,

null);

mTabHost.addTab(mTabHost.newTabSpec("throttle").setIndicator("Throttle"),

LoaderThrottleSupport.ThrottledLoaderListFragment.class,

null);

}

}Fragment中使用import

com.example.android.supportv4.R;

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("simple").setIndicator("Simple"),

FragmentStackSupport.CountingFragment.class,

null);

mTabHost.addTab(mTabHost.newTabSpec("contacts").setIndicator("Contacts"),

LoaderCursorSupport.CursorLoaderListFragment.class,

null);

mTabHost.addTab(mTabHost.newTabSpec("custom").setIndicator("Custom"),

LoaderCustomSupport.AppListFragment.class,

null);

mTabHost.addTab(mTabHost.newTabSpec("throttle").setIndicator("Throttle"),

LoaderThrottleSupport.ThrottledLoaderListFragment.class,

null);

return

mTabHost;

}

@Override

public

void

onDestroyView()

{

super.onDestroyView();

mTabHost

=

null;

}

}FragmentTabHost布局问题官方在给出例子的时候，并没有贴出对应的布局文件，这个布局文件有一些要求，所以我就把我自己写的贴出来吧，方便大家观看<?xml

version="1.0"

encoding="utf-8"?>

<LinearLayout

xmlns:android="/apk/res/android"

xmlns:app="/apk/res-auto"

xmlns:tools="/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:orientation="vertical"

tools:context="com.study.buttomtabdemo.MainActivity">

<FrameLayout

android:id="@+id/flayout_content"

android:layout_width="match_parent"

android:layout_height="0dp"

android:layout_weight="1"/>

<com.study.buttomtabdemo.widget.FragmentTabHost

android:id="@android:id/tabhost"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:background="#ffffff">

<FrameLayout

android:id="@android:id/tabcontent"

android:layout_width="0dp"

android:layout_height="0dp"

android:layout_weight="0"/>

</com.study.buttomtabdemo.widget.FragmentTabHost>

</LinearLayout>这里要注意以下几点：1.我自己自定义了一个FragmentTabHost，因为原来的FragmentTabHost每次切换Fragment事都会走一遍onCreateView（）和onResume（）方法；2.id必须是android:id=”@android:id/tabhost”这个；3.里面的FrameLayout的id必须是android:id=”@android:id/tabcontent”FragmentTabHost使用下面就到了具体使用的过程了1.定义Tab类因为它属于Tab的一个组合吧，里面包含好多个Tab，所以我们先定义一个Tab类/**

*

主页TAB对应实体

*

Created

by

HFS

on

2017/5/7.

*/

public

class

Tab

{

private

int

title;

//

文字

private

int

icon;

//

图标

private

Class

fragment;

//

对应fragment

public

Tab(Class

fragment,int

title,

int

icon

)

{

this.title

=

title;

this.icon

=

icon;

this.fragment

=

fragment;

}

public

int

getTitle()

{

return

title;

}

public

void

setTitle(int

title)

{

this.title

=

title;

}

public

int

getIcon()

{

return

icon;

}

public

void

setIcon(int

icon)

{

this.icon

=

icon;

}

public

Class

getFragment()

{

return

fragment;

}

public

void

setFragment(Class

fragment)

{

this.fragment

=

fragment;

}

}这里面要对应相应的Fragment，所以需要一个Fragment对象2.初始化Tab集合有几个Tab就往Tab集合添加几个Tab

Tab

tab_home

=

new

Tab(HomeFragment.class,R.string.home,R.drawable.selector_icon_home);

Tab

tab_hot

=

new

Tab(HotFragment.class,R.string.hot,R.drawable.selector_icon_hot);

Tab

tab_category

=

new

Tab(CategoryFragment.class,R.string.catagory,R.drawable.selector_icon_category);

Tab

tab_cart

=

new

Tab(CartFragment.class,R.string.cart,R.drawable.selector_icon_cart);

Tab

tab_mine

=

new

Tab(MineFragment.class,R.string.mine,R.drawable.selector_icon_mine);

mTabs.add(tab_home);

mTabs.add(tab_hot);

mTabs.add(tab_category);

mTabs.add(tab_cart);

mTabs.add(tab_mine);3.setUp找到该控件之后，就要调用对应的这个方法

mInflater

=

LayoutInflater.from(this);

mTabhost

=

(FragmentTabHost)

this.findViewById(android.R.id.tabhost);

mTabhost.setup(this,getSupportFragmentManager(),R.id.flayout_content);4.添加TabSpec到这一步就要添加TabSpec了，有几个Tab，就添加几个TabSpec

for

(Tab

tab

:

mTabs){

TabHost.TabSpec

tabSpec

=

mTabhost.newTabSpec(getString(tab.getTitle()));

tabSpec.setIndicator(buildIndicator(tab));

mTabhost.addTab(tabSpec,tab.getFragment(),null);

}

//构建Indicator

private

View

buildIndicator(Tab

tab){

View

view

=mInflater.inflate(R.layout.tab_indicator,null);

ImageView

img

=

(ImageView)

view.findViewById(R.id.icon_tab);

TextView

text

=

(TextView)

view.findViewById(R.id.txt_indicator);

img.setBackgroundResource(tab.getIcon());

text.setText(tab.getTitle());

return

view;

}5.设置默认显示第一个mTabhost.setCurrentTab(0);6.设置没有分割线mTabhost.getTabWidget().setShowDividers(LinearLayout.SHOW_DIVIDER_NONE);自定义FragmentTabHost类package

com.study.buttomtabdemo.widget;

/**

*

Created

by

monkey

*

on

2014/9/24

*

功能描述：修改过的FragmentTabHost,保存fragment实例不销毁

*/

/*

*

Copyright

(C)

2012

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

*

*

/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.

*/

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.view.ViewGroup;

import

android.widget.FrameLayout;

import

android.widget.LinearLayout;

import

android.widget.TabHost;

import

android.widget.TabWidget;

/**

*

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.

*

*

<p>

*

Here

is

a

simple

example

of

using

a

FragmentTabHost

in

an

Activity:

*

*

{@sample

*

development/samples/Support4Demos/src/com/example/android/supportv4/app/

*

FragmentTabs.java

complete}

*

*

<p>

*

This

can

also

be

used

inside

of

a

fragment

through

fragment

nesting:

*

*

{@sample

*

development/samples/Support4Demos/src/com/example/android/supportv4/app/

*

FragmentTabsFragmentSupport.java

complete}

*/

public

class

FragmentTabHost

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

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

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

Creator<SavedState>

CREATOR

=

new

Creator<SavedState>()

{

public

SavedState

createFromParcel(Parcel

in)

{

return

new

SavedState(in);

}

public

SavedState[]

newArray(int

size)

{

return

new

SavedState[size];

}

};

}

public

FragmentTabHost(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

FragmentTabHost(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);

}

private

void

ensureHierarchy(Context

context)

{

//

If

owner

hasn't

made

its

own

view

hierarchy,

then

as

a

convenience

//

we

will

construct

a

standard

one

here.

if

(findViewById(android.R.id.tabs)

==

null)

{

LinearLayout

ll

=

new

LinearLayout(context);

ll.setOrientation(LinearLayout.VERTICAL);

addView(ll,

new

LayoutParams(

ViewGroup.LayoutParams.MATCH_PARENT,

ViewGroup.LayoutParams.MATCH_PARENT));

TabWidget

tw

=

new

TabWidget(context);

tw.setId(android.R.id.tabs);

tw.setOrientation(TabWidget.HORIZONTAL);

ll.addView(tw,

new

LinearLayout.LayoutParams(

ViewGroup.LayoutParams.MATCH_PARENT,

ViewGroup.LayoutParams.WRAP_CONTENT,

0));

FrameLayout

fl

=

new

FrameLayout(context);

fl.setId(android.R.id.tabcontent);

ll.addView(fl,

new

LinearLayout.LayoutParams(0,

0,

0));

mRealTabContent

=

fl

=

new

FrameLayout(context);

mRealTabContent.setId(mContainerId);

ll.addView(fl,

new

LinearLayout.LayoutParams(

LinearLayout.LayoutParams.MATCH_PARENT,

0,

1));

}

}

/**

*

@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)

{

ensureHierarchy(context);

//

Ensure

views

required

by

super.setup()

super.setup();

mContext

=

context;

mFragmentManager

=

manager;

ensureContent();

}

public

void

setup(Context

context,

FragmentManager

manager,

int

containerId)

{

ensureHierarchy(context);

//

Ensure

views

required

by

super.setup()

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(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.hide(info.fragment);

mit();

}

}

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.fragment

!=

null)

{

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);

ft.hide(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)

{

mitAllowingStateLoss();

mFragmentManager.executePendingTransactions();

}

}

@Override

protected

void

onDetachedFromWindow()