FragmentTabHost的使用

现在市面上app的主流框架大体分为两种：一种是在主界面点击菜单按钮，之后会滑出侧滑菜单，之后进入到各个模块，还有一种是在主界面的下面放置若干个tab按钮，点击按钮，切换到不同的模块。今天要讲的就是第二种的实现方式之一的FragmentTabHost.（选项卡）

一： 首先我们看看XML:

1.activity_main.xml

<FrameLayout
    android:id="@+id/layout_frame"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/white" />

<android.support.v4.app.FragmentTabHost
    android:id="@android:id/tabhost"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="bottom">

    <FrameLayout
        android:id="@android:id/tabcontent"
        android:layout_width="0dp"
        android:layout_height="0dp" />
</android.support.v4.app.FragmentTabHost>

2.tab.xml

<LinearLayout
    android:id="@+id/ll_tab"
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:background="@color/tab_bg"
    android:gravity="center"
    android:orientation="vertical">

    <ImageView
        android:id="@+id/tab_icon"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="5dp"
        android:background="@color/tab_bg"
        android:src="@mipmap/nav_icon_home_sel" />

    <TextView
        android:id="@+id/tab_title"
        style="@style/CustomTextViewStyle03"
        android:layout_marginTop="3dp"
        android:text="首页" />

</LinearLayout>

3,Activity中使用如下：

/**
 * tabhost选项卡
 */
private TabWidget mTabWidget;
private FragmentTabHost mTabHost;

/**
 * 要加载所有的Fragment
 */
private Class<?>[] mFragments = {HomeFragment.class, OrderFragment.class, SelectCarFragment.class, CustomerFragment.class, MineFragment.class,};

private String[] titles = new String[]{"首页", "订单", "底价购车", "客服", "我的"};


mTabHost = findViewByIdNoCast(android.R.id.tabhost);
mTabHost.setup(this, getSupportFragmentManager(), R.id.layout_frame);
//获取一个TabWiidget
mTabWidget = mTabHost.getTabWidget();
mTabWidget.setDividerDrawable(null);

//为tabHost添加fragment
int menuCount = mFragments.length;
for (int i = 0; i < menuCount; i++) {
    TabHost.TabSpec spec = mTabHost.newTabSpec(titles[i]).setIndicator(getItemView(i));
    mTabHost.addTab(spec, mFragments[i], null);
}

private View getItemView(int index) {
    View view = LayoutInflater.from(this).inflate(R.layout.tab, null);
    TextView tv = (TextView) view.findViewById(R.id.tab_title);
    ImageView icon = (ImageView) view.findViewById(R.id.tab_icon);
    return view;
}

//为FragmentTabHost添加点击事件
mTabHost.setOnTabChangedListener(new TabHost.OnTabChangeListener() {
    @Override
    public void onTabChanged(String tabName) {
for (int i = 0; i < mTabWidget.getTabCount(); i++) {

    View view = mTabWidget.getChildTabViewAt(i);

    TextView tab_title = (TextView) view.findViewById(R.id.tab_title);
    ImageView tab_icon = (ImageView) view.findViewById(R.id.tab_icon);
    if (i == mTabHost.getCurrentTab()) {
        current_tab = i;
        tab_icon.setImageResource(iconS[i]);
        tab_title.setTextColor(Color.parseColor("#ffff4b14"));
    } else {
        tab_title.setTextColor(Color.rgb(162, 172, 181));
        tab_icon.setImageResource(iconN[i]);
    }
}
    }
});
//指定tabhost选中那一个
mTabHost.setCurrentTab(0);

//根据tabId获取Fragment
private Fragment getFragment(int tabId)
{
    List<Fragment> fragments = getSupportFragmentManager().getFragments();
    for(Fragment fragment : fragments) {
        String str1 = fragment.getTag();
        String str2 = String.valueOf("TAB_TAG_" + tabId);
        if(str1 != null && str1.equals(str2)) // 最开始没有检查str1是否为空，导致crash！
            return fragment;
    }
    return null;
}